University of Surrey
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Professor David Bradley

Emeritus Professor

Academic and research departments

School of Mathematics and Physics.

About

Biography

David Bradley (PhD (USM), MSc (London), BSc (Exeter)) is Professor of Radiation and Medical Physics at the University of Surrey. He has taught and researched in Universities for some 35 years. For some 14 years he Directed MSc programmes in Medical Physics. He was also for six years the Secretary of the International Radiation Physics Society (IRPS). Presently he is Editor-in-Chief of the British Journal of Radiology and Consulting Editor to the Elsevier journals 'Applied Radiation and Isotopes' and 'Radiation Physics and Chemistry'. Dr Bradley is the author of over 250 publications and has made more than 150 presentations at conferences. His interests are in researching the fundamental interactions of radiation in matter as well as their applications in biomedical areas and in industry.

University roles and responsibilities

Course Deputy Director for the MSc Programme in Medical Physics and the MSc Programme in Medical Physics

Research

Research interests

Dr Bradley has active research interests in the fundamentals and applications of photon scattering, radioanalytical techniques for determination of trace element concentrations, radiological risks associated with Naturally Occurring Radioactive Material (NORM), the development of synchrotron techniques for characterisation of media, predominantly biological tissues, radiation effects on tissues, and development of silica based luminesence dosimeters.

Research projects of current interest include: the localisation of Zn and Sr in synovial joints, the development of doped radiosensitive glass, the effects of ionizing radiation on extracellular matrix, and near-edge elastic photon scattering from dilute aqueous ions.

Teaching

Module Leader for PHYM018 Radiation Protection.

Publications

Ali Taheri, Mayeen Uddin Khandaker, Farhad Moradi, David Andrew Bradley (2024)A simulation study on the radiosensitization properties of gold nanorods, In: Physics in medicine & biology69(4)

Gold nanorods (GNRs) have emerged as versatile nanoparticles with unique properties, holding promise in various modalities of cancer treatment through drug delivery and photothermal therapy. In the rapidly evolving field of nanoparticle radiosensitization (NPRS) for cancer therapy, this study assessed the potential of gold nanorods as radiosensitizing agents by quantifying the key features of NPRS, such as secondary electron emission and dose enhancement, using Monte Carlo simulations. Approach: Employing the TOPAS track structure code, we conducted a comprehensive evaluation of the radiosensitization behavior of spherical gold nanoparticles and gold nanorods. We systematically explored the impact of nanorod geometry (in particular size and aspect ratio) and orientation on secondary electron emission and deposited energy ratio, providing validated results against previously published simulations. Main Results: Our findings demonstrate that gold nanorods exhibit comparable secondary electron emission to their spherical counterparts. Notably, nanorods with smaller surface-area-to-volume ratios (SA:V) and alignment with the incident photon beam proved to be more efficient radiosensitizing agents, showing superiority in emitted electron fluence. However, in the microscale, the deposited energy ratio (DER) was not markedly influenced by the SA:V of the nanorod. Additionally, our findings revealed that the geometry of gold nanoparticles has a more significant impact on the emission of M-shell Auger electrons (with energies below 3.5 keV) than on higher-energy electrons. Significance: This research investigated the radiosensitization properties of gold nanorods, positioning them as promising alternatives to the more conventionally studied spherical gold nanoparticles in the context of cancer research. With increasing interest in multimodal cancer therapy, our findings have the potential to contribute valuable insights into the perspective of gold nanorods as effective multipurpose agents for synergistic photothermal therapy and radiotherapy. Future directions may involve exploring alternative metallic nanorods as well as further optimizing the geometry and coating materials, opening new possibilities for more effective cancer treatments.

Muhammad Azlan, Heryanto Heryanto, Abdelmoneim Sulieman, David A. Bradley, Dahlang Tahir (2024)Composite Cassava Starch/Rhizophora spp particleboards/Zn nanoparticle for phantom applications, In: Radiation physics and chemistry (Oxford, England : 1993)218111587 Elsevier Ltd

This paper presents the fabrication of Cassava Starch/Rhizophora Spp/Zn nanoparticle composite as a phantom for X-ray radiation. The use of phantoms is crucial in controlling the quality of radiation doses in medical applications. The composite materials were synthesized using a sol-gel method, and the structural properties were characterized using X-ray Diffraction (XRD) and bonding characteristics by Fourier transform infrared spectrophotometry (FTIR). Mechanical testing was performed to assess the physical and mechanical properties of the phantoms. The linear attenuation coefficient and mass attenuation coefficient were determined using CT-Scan and Mobile X-ray tests. The results showed that the composite materials exhibited amorphous characteristics with crystal structure patterns. The addition of Zn nanoparticles affected the diffraction intensity and crystal size. The FTIR analysis revealed the presence of functional groups such as hydroxyl, alkane, siloxane, alkene, and ether bonds in the composite. The synthesized phantom composites showed potential as substitutes for commercial phantoms due to the Cassava starch/Rhizophora spp/Zn 1gr phantom is generally close to the attenuation coefficient value of the human liver phantom reported in previous studies, which is about 0.293 cm−1. This suggests that this phantom composite has a good potential as a substitute for human liver tissue in X-ray testing. •The phantom research as X-ray testing have explored various materials.•The composite materials were synthesized using a sol-gel method.•We found the best for liver phantom is phantom with 1 gr Zn in composite.•Attenuation coefficient value for human liver phantom is about 0.293 cm–1.

Abdullah Almujally, Saad Alenezi, Khalid Nasser Alddosary, Ahmed Otayni, Abdelmoneim Sulieman, Amr Abdelghani, Nissren Tamam, Raafat Mohtasib, Ahmed Masawi, Belal Moftah, D.A. Bradley (2023)Abdomen and pelvis computed tomography procedure: Effective dose assessment and establishment of a local diagnostic reference level, In: Radiation physics and chemistry (Oxford, England : 1993)203 Elsevier Ltd

Exposure to ionizing radiation may induce cancer risk to the patients proportional to the radiation absorbed dose and the organ sensitivity. Therefore protection of radiation exposure is essential to minimize the radiation cancer risk and prevent the deterministic effects. The International Atomic Energy Agency (IAEA) encourages member countries to establish national diagnostic reference levels (DRLs) to reduce unjustified radiation exposure. This study establishes a local DRL for computed tomography (CT) abdomen and pelvis procedures. In total, 1444 CT abdomen procedures were carried out during nine months. CT abdomen procedures were carried out at King Faisal Specialist Hospital and research center using six CT machines from different vendors. The mean and range of patients' weight (kg) are 50 (42–120). The recommended DRLs values in DLP (mGy.cm) and CTDIvol (mGy) were 900 and 15 per CT abdomen and pelvis procedure, respectively. 3% (41 cases) were higher than the national DRL for CT abdomen and pelvis. The proposed DRL values are slightly higher than the European and the American College of Radiologists (ACR) DRL values in DLP. The purpose of DRL in terms of CTDIvol (mGy) is comparable with the international guidelines. Thus reducing the scan length, is recommended ensuring that patients receive a minimal possible radiation dose while maintaining the image quality. •Patient radiation was calculated for CT abdomen examinations.•Six multi-detector CT machines 64, 128, 384 and 256 (three machines) were used.•3% (41 cases) were higher than the national DRL for CT abdomen and pelvis.•The proposed DRL is higher than previously reported values in Europe.

A. A. Z. Ahmad Nazeri, S. F. Abdul Sani, N. M. Ung, K. S. Almugren, F. H. Alkallas, D. A. Bradley (2021)Borosilicate glass 60Co high dose rate brachytherapy thermoluminescence dosimetry, In: Applied radiation and isotopes176 Elsevier

Brachytherapy is commonly used in treatment of cervical, prostate, breast and skin cancers, also for oral cancers, typically via the application of sealed radioactive sources that are inserted within or alongside the area to be treated. A particular aim of the various brachytherapy techniques is to accurately transfer to the targeted tumour the largest possible dose, at the same time minimizing dose to the surrounding normal tissue, including organs at risk. The dose fall-off with distance from the sources is steep, the dose gradient representing a prime factor in determining the dose distribution, also representing a challenge to the conduct of measurements around sources. Amorphous borosilicate glass (B2O3) in the form of microscope cover slips is recognized to offer a practicable system for such thermoluminescence dosimetry (TLD), providing for high-spatial resolution (down to < 1 mm), wide dynamic dose range, good reproducibility and reusability, minimal fading, resistance to water and low cost. Herein, investigation is made of the proposed dosimeter using a 1.25 MeV High Dose Rate (HDR) Co-60 brachytherapy source, characterizing dose response, sensitivity, linearity index and fading. Analysis of the TL glow curves were obtained using the T-max -T-stop method and first-order kinetics using GlowFit software, detailing the frequency factors and activation energy.

Yarima Mudassir Hassan, Hasnah Muhd Zaid, Beh Hoe Guan, Mayeen Uddin Khandaker, D. A. Bradley, A. Sulieman, Sk A. Latif (2021)Radioactivity in staple foodstuffs and concomitant dose to the population of Jigawa state, Nigeria, In: Radiation physics and chemistry (Oxford, England : 1993)178 Elsevier

In addition to the presence of primordial radionuclides, inputs from technological progress together with nuclear technology proliferation have also contributed to the level of radioactivity in the soil. Due to the transfer of radionuclides in the chain soil-plant-human, notably via the ingestion pathway, it is important to assess the concentrations of radioactive materials in staple foodstuffs. Present study via HPGe gamma-ray spectrometry was undertaken to measure the concentrations of Ra-226, Ra-228 and K-40 in the more prominent staple Nigerian foodstuffs (rice, wheat, and millet). For Ra-226, Ra-228 and K-40, the activity concentrations (Bq/kg) in rice were in the respective range of 0.9-2.4, 0.5-2.4 and 78-326, while for wheat they were 1.3-5.1, 0.7-1.2 and 192-264, and for millet the range of 2.5-9.9, 0.8-1.9 and 186-197 in the same order. Overall, the measured data were found to be below the global average values of 67 Bq/kg, 82 Bq/kg and 310 Bq/kg prescribed by UNSCEAR for Ra-226 Ra-228 and K-40, respectively. The committed effective dose via consumption of the studied foodstuffs shows millet to have the greatest contribution, albeit not superseding the dose limit of 290 mu Sv/y proposed by UNSCEAR. The threshold consumption rates for the studied foodstuffs were within the range of 66-343 kg/y (mean value 153 kg/y), approximating to individual consumption of similar to 419 g/d, not equating to unacceptable radiological risk. The lifetime cancer risk from consumption of the studied food was also assessed and found to be below the ICRP (2013) cancer risk factor of 4.5 x 10(-3) based on an additional annual dose limit of 1 mSv (above background) for the general public. In summary, consumption of the studied foodstuffs poses an insubstantial threat to the public.

K.S. Almugren, S.F. Abdul Sani, M.S. Jaafar, Azhar Mohamad, A.S Siti Shafiqah, D.A. Bradley (2023)The effect of acute gamma radiation onto growth media for mother culture of a Volvariella mushroom, In: Radiation physics and chemistry (Oxford, England : 1993)202 Elsevier Ltd

Potato Dextrose Agar (PDA) is a semicrystalline polymer made from amylopectin, agarose, and amylose, used in laboratories for Agar plate culturing for a multitude of fungal strains. The existing pretreatment method for the elimination of pathogenic bacteria, namely steam sterilization, has shown several drawbacks, including high cost, uneven heating due to temperature differentials and an inability to treat specimens volumetrically. These drawbacks are mitigated by gamma irradiation, being carried out in order to improve hygienic quality and germination control, retarding sprouting, also enhancing physical attributes of the food product. Present study investigates the growth and survival of pretreated potato dextrose agar (PDA) substrate with gamma irradiations, for doses ranging from 0 kGy (unirradiated) up to 20 kGy, particularly for Volvariella mushroom cultivation. The relative elemental composition of PDA substrate has been obtained through use of Energy Dispersive X-ray Analysis (EDX), identifying carbohydrate (53.35%), oxygen (45.29%) and 1.36% of mineral trace elements. Gamma irradiation doses to the PDA substrate of 0.5 kGy, 1 kGy and 1.5 kGy have been found to be associated with respective growth rates of 0.93 ± 0.03, 0.94 ± 0.02 and 0.89 ± 0.02 cm/day, the PDA becoming more amorphous and acidic with reduced viscosity at higher doses. The findings of this study could pave the way for a low-cost yet highly effective system for irradiation in mushroom, as well as offering a viable alternative to current conventional sterilizations, well suited to applications in food security. •Potato dextrose agar (PDA) substrate irradiated with gamma at 0.5–20 kGy.•PDA substrate used for Volvariella mushroom cultivation.•PDA substrate becoming amorphous and acidic with reduced viscosity at higher doses.•PDA substrate of 1 kGy have been found to produce effective growth rates.•Gamma irradiation shows an alternative and effective method of sterilization.

A. Sulieman, N. Tamam, Abdelrahman Elnour, M. Alkhorayef, E. Babikir, Huda I. Al-Mohammed, N. Abuhadi, Mayeen Uddin Khandaker, David A. Bradley (2022)Effective radiation dose and radiogenic cancer risk during contrast enhanced abdominal computed tomography examinations, In: Radiation physics and chemistry (Oxford, England : 1993)200 Elsevier Ltd

Pediatrics and children have higher radiosensitivity to ionizing radiation and radiogenic risks than adults due to their rapidly dividing tissues. This study explores the infant and children radiation doses during computed tomography (CT) abdomen and estimates the cancer risk from the procedure. In total, 87 were examined for CT enhanced abdominal examination. The abdominal CT scan with contrast was performed using a 128-slice multi slice CT (MSCT) scan. The mean, standard deviation, and range of patients' age (years) are 13 ± 4.5 (2–17). The mean and range of the air kerma length product (PKL(mGy.cm)) and volume CT air kerma index (Cvol (mGy)) were 1740 (157.8–8440.3) (mGy.cm) and 9.8 (2.09–45.77) (mGy) per CT abdomen procedure, respectively. The mean and range of the effective dose (mSv) per procedure are 34 (3.14–176.8). The average radiogenic risk per CT procedure is one cancer incidence per 250 CT enhanced abdomen procedures. The mean and range of total irradiation even are 4.0 (2.0–8.0) times per procedure. The results of this study showed that child risk is high compared to other CT examinations. Therefore, patients’ dose optimization and proper establishment of a diagnostic reference level (DRL) are necessary to preventing avoidable radiation risks. •Radiation dose were assessed for 87 abdomen Contrast enhanced Computed tomography (CECT) examinations.•The average radiogenic risk per CT procedure is one cancer incidence per 250 CT enhanced abdomen procedures.•The results of this study showed that child risk is high compared to other CT examinations.•The results obtained in this study are similar to those reported in previous studies.

Thanh-Nghia Nguyen, Thanh-Tai Duong, Hiba Omer, Abdelmoneim Sulieman, David A. Bradley (2023)The Design and Construction of a 12-Channel Electrocardiogram Device Developed on an ADS1293 Chip Platform, In: Electronics (Basel)12(11)2389 Mdpi

An accurate and compact electrocardiogram (ECG) device will greatly assist doctors in diagnosing heart diseases. It will also help to address the increasing number of deaths caused by heart disease. Accordingly, the goal of the project is to design and construct an easy-to-use compact 12-lead electrocardiogram device that communicates with a computer to create a system that can continuously monitor heart rate and which can be connected to allied medical systems. The design is based on an ECG receiver circuit utilizing an IC ADS1293 and an Arduino Nano. The ADS1293 has built-in input Electromagnetic Interference (EMI) filters, quantizers, and digital filters, which help in reducing the size of the device. The software has been created using the C# programming language, with Windows Presentation Foundation (WPF), aiding the collection of the ECG signals from the receiving circuit via the computer port. An ECG Multiparameter Simulator has been used to calibrate the ECG device. Finally, a plan has been developed to connect the arrangement to health systems according to HL7 FHIR (Health Level Seven Fast Healthcare Interoperability Resources) through Representational State Transfer Application Programming Interface (Rest API). The ECG device, completed at the cost of U$169 excluding labor, allows for the signal of 12 leads of ECG signal to be obtained from 10 electrodes mounted on the body. The processed ECG data was written to a JSON file with a maximum recording time of up to three days, managed by a Structured Query Language Server (SQL) Server database. The software retrieves patient data from electrical medical records in accordance with HL7 FHIR standards. A compact and easy-to-use ECG device was successfully designed to record ECG signals. An in-house developed software was also completed to display and store the ECG signals.

Eltayeb Osman, A. Sulieman, Khalid Alzimami, N. Tamam, Layal K. Jambi, E. Babikir, Amr A. Abd-Elghany, M. Abuzaid, Hiba Omer, D.A. Bradley (2021)Radiation exposure during therapeutic cardiac interventional procedures, In: Radiation physics and chemistry (Oxford, England : 1993)188 Elsevier Ltd

The purpose the current work were to assess the radiation exposure given to patients during percutaneous coronary interventions (PCI), pacemaker (PM) and coronary angiography (CA), procedures. In total, 419 procedures were carried out in 4 specialized hospitals. Calibrated Kerma area product meters were used to quantify the patient doses. Effective dose was extrapolated using the national radiological protection board (NRPB) software program. The mean KAP (Gy.cm2) per procedure were 8.6, 6.2 and 5.6 for PCI, PM, and CA procedures, respectively. While in that order, e mean and Entrance Surface Air Kerma (ESAK, mGy) per procedure were 705.9,509, and 464.7 for PCI, PM, and CA. Patients’ doses is below the level of the deterministic effects and the effective dose per procedure is low. Patients radiation doses is lowest compared to the previous studies. •Patients' radiation doses were monitored during cardiac catheterization procedures.•The patient's doses were measured using a Kerma area product meter (KAP).•The variances in radiation doses incurred during PCI were greater than the variance in doses incurred in CA and pacemaker.•DRL values derived in this study were comparable with values reported in international literature.

Ming Tsuey Chew, Eman Daar, Mayeen Uddin Khandaker, Bleddyn Jones, Andrew Nisbet, David A Bradley (2021)Low radiation dose to treat pneumonia and other inflammations, In: British journal of radiology94(1124)pp. 20201265-20201265

Infection, the invasion of pathogenic microorganisms and viruses, causes reactive inflammation mediated by endogenous signals, with influx of leucocytes with distinct properties and capable of mounting a cellular or antibody response. Different forms of inflammation may also occur in response to tumours, in allergy and autoimmune disorders. Pneumonia, respiratory tract infection and septic shock for instance can arise as serious complications of the Covid-19 virus. While radiotherapy has been most widely used to control malignant tumours, it has also been used for treatment of non-malignant diseases, including acute and chronic inflammation in situations where anti-inflammatory drugs may be ineffective or contraindicated. The present review examines the history and prospects for low-dose anti-inflammatory radiation treatments, the present interest largely being motivated by the increased incidence of pulmonary disease associated Covid-19 infections. Evidence in support of the suggested efficacy are covered, together with an appraisal of one of the number of potential convenient sources that could complement external beam arrangements.

Md. Refat Jahan Rakib, Y. N. Jolly, Christian Ebere Enyoh, Mayeen Uddin Khandaker, M. Belal Hossain, Shirin Akther, Abdullah Alsubaie, Abdulraheem S. A. Almalki, D. A. Bradley (2021)Levels and health risk assessment of heavy metals in dried fish consumed in Bangladesh, In: Scientific reports11(1)pp. 14642-14642 Nature Publishing Group UK

As a cheap source of high-quality protein, healthy fats and essential nutrients, dried fish is a common item in the daily diet of the Bangladesh populace. In this study, ten types of widely consumed dried fish ( H. neherius, T. lepturu, P.chinensis, P. affinis, A. mola, P. microdon, I. megaloptera, C. dussumieri, L. calcarifer, and G. chapra ) were analyzed for Cr, Mn, Fe, Co, Cu, Zn, Se, Rb, Hg, Pb, Ni and As by using an Energy Dispersive X-ray Fluorescence (EDXRF) technique. The concentration of the studied metals was found in the order Fe > Zn > Hg > Cu > Se > Cr > Mn > Co > Rb > Pb, while As and Ni were below the limit of detection. All fish species showed moderate to high pollution, where the species H. Neherius and P. Chinensis are the most and least polluted ones, respectively. The probable source of contamination is the leaching from the drying pans into the fish samples, atmospheric deposition, anthropogenic contamination, etc. of the water body where these fish were harvested. The calculated hazard index for the general population was below the maximum limiting value (i.e.,

Entesar Zawam Dalah, Abdulmunhem Obaideen, Sabaa Anam, Khalid Alzimami, Layal Khalid Jambi, David A Bradley (2022)Gender based lung cancer risks for symptomatic coronary artery disease patients undergone cardiac CT, In: PloS one17(4)pp. e0265609-e0265609

We estimate the lifetime attributable risk (LAR) of lung cancer incidence in symptomatic Coronary Artery Disease (CAD) patients receiving enhanced Coronary Computed Tomography Angiography (CCTA) and the unenhanced Computed Tomography Calcium Scoring (CTCS) examination. Retrospective analysis has been made of CCTA and CTCS data collected for 87 confirmed CAD adult patients. Patient effective dose (E) and organ doses (ODs) were calculated using CT-EXPO. Statistical correlation and the differences between E and ODs in enhanced CCTA and unenhanced CTCS were calculated using the Pearson coefficient and Wilcoxon unpaired t-test. Following BEIR VII report guidance, organ-specific LARs for the cohort were estimated using the organ-equivalent dose-to-risk conversion factor for numbers of cases per 100,000 patients exposed to low doses of 0.1 Gy. Significant statistical difference (p

Md. Refat Jahan Rakib, Sultan Al Nahian, María B. Alfonso, Mayeen Uddin Khandaker, Christian Ebere Enyoh, Fauziah Shahul Hamid, Abdullah Alsubaie, Abdulraheem S. A. Almalki, D. A. Bradley, Hamidreza Mohafez, Mohammad Aminul Islam (2021)Microplastics pollution in salt pans from the Maheshkhali Channel, Bangladesh, In: Scientific reports11(1)pp. 23187-23187 Nature Publishing Group UK

Microplastics (MP) were recognized as an emergent pollution problem due to their ubiquitous nature and bioaccumulative potential. Those present in salt for consumption could represent a human exposure route through dietary uptake. The current study, conducted in Bangladesh, reports microplastics contamination in coarse salt prepared for human consumption. Sea salt samples were collected from eight representative salt pans located in the country's largest salt farming area, in the Maheshkhali Channel, along the Bay of Bengal. Microplastics were detected in all samples, with mean concentrations ranging from 78 ± 9.33 to 137 ± 21.70 particles kg −1 , mostly white and ranging in size from 500–1000 µm. The prevalent types were: fragments (48%) > films (22%) > fibers (15%) > granules and lines (both 9%). Fourier transform mid-IR and near-IR spectra (FT-MIR-NIR) analysis registered terephthalate (48%), polypropylene (20%), polyethylene (17%), and polystyrene (15%) in all samples. These results contribute to the MP's pollution knowledge in sea salts to understand and reduce this significant human exposure route and environmental pollution source in the future.

H.G. Sarhan, S.M. Saini, N.M. Bahari, D.A. Bradley, H.T. Zubair, A. Basaif, A.A. Oresegun, H.A. Abdul Rashid, N. M. Noor (2023)Real-time germanium-doped optical fibers for clinical computed tomography dosimetry, In: Radiation physics and chemistry (Oxford, England : 1993)209 Elsevier Ltd

In studies focusing on the practice of clinical computed tomography (CT) a particular concern has been that of delivering unnecessary dose to patients and with it the added risk for radiation-induced cancers. For a CT system, present work has investigated the dosimetric characteristics of a Ge-doped optical fiber real-time dosimetry system (model LS-2000, Lumisyns), measuring beam quality, exposure linearity and exposure duration accuracy. For comparison, the study has used a RaySafe X2 test device (Unfors RaySafe) and a Black Piranha (RTI) QA meter. Irradiations were made using a Somatom Definition Flash dual-source 128-slice CT scanner (Siemens Healthcare). The LS-2000, RaySafe X2, and Black Piranha sensors were exposed to beams energized at accelerating potentials ranging from 80 to 140 kVp, with tube current-time products from 50 to 300 mA, and exposure durations from 750 to 2000 ms. Constant signal responses from the LS-2000 have been obtained, measured in respect of beam quality, exposure linearity, and time accuracy. In respect of accuracy of beam quality, the RaySafe X2 and Black Piranha maximum deviations were 1% and 5%, respectively; the coefficients of linearity of RaySafe, Black Piranha and LS-2000 are 1%, 0.4% and 1.4%, respectively; the maximum deviation for the time accuracy test for the three sensors are 0.5%, 2% and 1.3%, respectively. Evaluation of the LS-2000 real-time dosimetry system with a Ge-doped optical fiber scintillator points to potential for its use in clinical CT dosimetry. •We investigate the real-time Ge-doped for clinical computed tomography (CT).•The comparison has been made used of Unfors and RTI QA meters.•The beam quality, exposure linearity and exposure duration accuracy were established.•The LS-2000 shows good potential for use in Clinical CT dosimetry.

Meshari Alnaaimi, Abdelmoneim Sulieman, Mohammed Alkhorayef, Hasan Salah, Musa Alduaij, Mosab Algaily, O. Alomair, Y. Alashban, H. Almohammad, David Bradley, C. Kappas (2021)Organs dosimetry in targeted radionuclide therapy, In: Radiation physics and chemistry (Oxford, England : 1993)188 Elsevier

The objective of this study is to assess the patients' effective and organ dose during theranostic applications in Kuwait. In total, eighteen adults' patients were conducted nuclear medicine procedures with 177Lu Dotatate for theranostic purpose in Kuwait Cancer control center (KCCC), Kuwait. Medium energy collimator (MEC) (208 keV Scatter 26% better than 113 keV Scatter 60%) was utilized to obtain scans in definite time intervals ranged from one to 2 h (before voiding), 6:00, 24:00, 48:00, 72:00 h. Patients, tissue and organ radiation doses were computed utilizing OLINDA/EXM Software. The average radiation effective dose (in mSv/MBq) for bladder, liver, and both kidneys (left & right), were 0.36, 0.08, 0.61 & 0.60. The range of the effective dose was from 0.55 mSv to 7.7 mSv. The acquired scans using 177Lu were delivered diagnostic findings. The patients' effective dose is lower compared to the previous studies. Variation is attributed to the departmental protocol and administered activity. The values of the mean organ dose were comparable and lower than previously published studies. Different organs have different level of doses, which may affected by the presence of the metastatic tumors in the entire organ.

Mayeen Uddin Khandaker, Nwokoma Oliver Chijioke, Nurul' Adillah Binti Heffny, David A. Bradley, Abdullah Alsubaie, Abdelmoneim Sulieman, Mohammad Rashed Faruque, M. Sayyed, K. S. Al-mugren (2021)Elevated concentrations of metal(Loids) in seaweed and the concomitant exposure to humans, In: Foods10(2) Mdpi

While the consumption of seaweed and seaweed-based products is very common amongst East Asian nations, forming a notable component of the daily diet, relatively very few studies have concerned the concentrations of heavy metals in these together with potential effects on human health. The present study analyses the concentrations of 17 elements in locally resourced seaweed, also assessing potential noncarcinogenic and carcinogenic risks. The samples were ground, homogenized, and quantified using the ICP-OES technique. It has been found that the essential elements K, Ca, Mg, Zn, and Na typically show concentrations somewhat greater than a number of potentially toxic metals, in particular, Cd, Pb, Ag, and As, with exceptions being Ni, Cr-VI, and Si. Statistical analysis indicates all of the latter to have similar origin, with increased concentration of these metals within the marine ecosystem. While the daily estimated intake of most metals is seen to be within the daily dietary allowance level recommended by various international organizations, the noncarcinogenic risk shows a value greater than unity, estimated via the hazard quotient. This indicates a potential for adverse effects to health arising from consumption of the sampled seaweed. The carcinogenic risk resulting from nonessential elements shows values greater than the United States Environmental Protection Agency (US-EPA) reference limit of 10(-4). Considering the nonbiodegradability of heavy metals and metalloids and their potential accumulation in seaweed, there is need for critical examination of metal levels in the seaweeds obtained from the present study locations, together with the introduction of practices of removal of heavy metals via bio-adsorbent techniques.

Matthew Tikpangi Kolo, Mayeen Uddin Khandaker, Matthew O. Isinkaye, Anayo Ugwuanyi, Nwachukwu Chibueze, Opeyemi Falade, Paul Onuche, Amal Alqahtani, D.A. Bradley, I.M. Ashraf (2023)Radon in groundwater sources of Bosso Community in North Central Nigeria and concomitant doses to the public, In: Radiation physics and chemistry (Oxford, England : 1993)203

H. I. Al-Mohammed, A. Sulieman, Fareed H. Mayhoub, Hassan Salah, Celestino Lagarde, M. Alkhorayef, Ali Aldhebaib, C. Kappas, D. A. Bradley (2021)Occupational exposure and radiobiological risk from thyroid radioiodine therapy in Saudi Arabia, In: Scientific reports11(1)pp. 14557-14557 NATURE PORTFOLIO

Worldwide, thyroid cancer accounts for some 10% of total cancer incidence, most markedly for females. Thyroid cancer radiotherapy, typically using I-131 (T-1/2 8.02 days; beta (-) max energy 606 keV, branching ratio 89.9%), is widely adopted as an adjunct to surgery or to treat inoperable cancer and hyperthyroidism. With staff potentially receiving significant doses during source preparation and administration, radiation protection and safety assessment are required in ensuring practice complies with international guidelines. The present study, concerning a total of 206 patient radioiodine therapies carried out at King Faisal Specialist Hospital and Research Center over a 6-month period, seeks to evaluate patient and occupational exposures during hospitalization, measuring ambient doses and estimating radiation risk. Using calibrated survey meters, patient exposure dose-rate estimates were obtained at a distance of 30-, 100- and 300 cm from the neck region of each patient. Occupational and ambient doses were measured using calibrated thermoluminescent dosimeters. The mean and range of administered activity (AA, in MBq) for the thyroid cancer and hyperthyroidism treatment groups were 4244 +/- 2021 (1669-8066), 1507.9 +/- 324.1 (977.9-1836.9), respectively. The mean annual occupational doses were 1.2 mSv, that for ambient doses outside of the isolation room corridors were found to be 0.2 mSv, while ambient doses at the nursing station were below the lower limit of detection. Exposures to staff from patients being treated for thyroid cancer were less compared to hyperthyroidism patients. With a well-defined protocol, also complying with international safety requirements, occupational exposures were found to be relatively high, greater than most reported in previous studies.

Jubair Al Mahmud, M. M. Mahfuz Siraz, Mohammad Shafiqul Alam, Sudeb Chandra Das, David Andrew Bradley, Mayeen Uddin Khandaker, Shinji Tokonami, Afroza Shelley, Selina Yeasmin (2023)A study into the long-overlooked carcinogenic radon in bottled water and deep well water in Dhaka, Bangladesh, In: International journal of environmental analytical chemistryahead-of-print(ahead-of-print)pp. 1-13 Taylor & Francis

Radon ( 222 Rn), a radioactive and gaseous progeny of Uranium ( 238 U) decay series, accounts for almost 50% of the total background radiation in our dwelling environment. Inhalation and ingestion of radon in excessive amounts pose serious health effects to humans. The first-ever measurement of radon concentration in commercial bottled water available in Dhaka city and deep well water samples from the campus of the University of Dhaka was carried out using the RAD7 Radon monitoring system. The concentration of radon in the bottled water ranged from 0.11 Bq/L to 1.30 Bq/L with a mean of 0.59 Bq/L, and the deep well water showed a mean of 4.88 Bq/L with a range of 3.02 Bq/L to 5.98 Bq/L. All twenty-five samples of water had radon concentrations within the recommended limits of USEPA and WHO. The mean annual effective doses from radon in bottled water and deep well water were evaluated to be 0.126 µSv/y and 12.481 µSv/y, respectively. Although the calculated doses indicate the least potential risk according to WHO and UNSCEAR, however, it is expected that the present results play an important role in setting up a national guideline for radon in drinking water, and the monitoring of radon for the safety of public health.

Wadah M. Ali, Abdelmoneim Sulieman, Hassan Salah, H. I. Almohammed, Mohammed Alkhorayef, D. A. Bradley (2021)Short-term retention of 99mTc activity in bone scintigraphy, In: Radiation physics and chemistry (Oxford, England : 1993)178 Elsevier

The objective of present study is estimation of the radioactivity held within the urinary bladder and kidneys 3 h post radiopharmaceutical (Tc-99m-MDP) administration, comparison being made via use of MIRDose. Using the conjugate-view method and built-in camera software Mediso XP Interview, urinary bladder and kidney radionuclide activities were calculated using patient clinical data acquired at the aforesaid 3 h post Tc-99m-MDP injection juncture. The study was of a cohort of 40 patients attending for staging and cancer follow-up at the Nuclear Medicine Department, Royal Care International Hospital (RCIH), Sudan, Ethical and Research Committee approval for the study having been obtained. The radioisotope biokinetics were simulated using the Medical Internal Radiation Dose (MIRD) biokinetics model, specifically in regard to radionuclide activity in the kidneys and bladder. The results were compared with the data achieved via clinical study, showing the experimentally estimated radionuclide activity in the kidney to be greater by some 50% compared to that of simulation while the bladder radionuclide activity was found to be just 2% of the simulation result. The study also found that 0.9% of the administered radioactivity remained in the urinary bladder and kidneys 3 h post administration of the radionuclide, suggestive of low radiation dose to the urinary bladder and kidneys post Tc-99m-MDP bone scans.

M. Kanmalar, Siti Fairus Abdul Sani, Nur Izzahtul Nabilla B. Kamri, Nur Akmarina B. M. Said, Amirah Hajirah B. A. Jamil, S. Kuppusamy, K. S. Mun, D. A. Bradley (2022)Raman spectroscopy biochemical characterisation of bladder cancer cisplatin resistance regulated by FDFT1: a review, In: Cellular & molecular biology letters27(1)pp. 9-9 BioMed Central

Bladder cancer is the fourth most common malignancy in males. It can present across the whole continuum of severity, from mild through well-differentiated disease to extremely malignant tumours with poor survival rates. As with other vital organ malignancies, proper clinical management involves accurate diagnosis and staging. Chemotherapy consisting of a cisplatin-based regimen is the mainstay in the management of muscle-invasive bladder cancers. Control via cisplatin-based chemotherapy is threatened by the development of chemoresistance. Intracellular cholesterol biosynthesis in bladder cancer cells is considered a contributory factor in determining the chemotherapy response. Farnesyl-diphosphate farnesyltransferase 1 (FDFT1), one of the main regulatory components in cholesterol biosynthesis, may play a role in determining sensitivity towards chemotherapy compounds in bladder cancer. FDFT1-associated molecular identification might serve as an alternative or appendage strategy for early prediction of potentially chemoresistant muscle-invasive bladder cancer tissues. This can be accomplished using Raman spectroscopy. Developments in the instrumentation have led to it becoming one of the most convenient forms of analysis, and there is a highly realistic chance that it will become an effective tool in the pathology lab. Chemosensitive bladder cancer tissues tend to have a higher lipid content, more protein genes and more cholesterol metabolites. These are believed to be associated with resistance towards bladder cancer chemotherapy. Herein, Raman peak assignments have been tabulated as an aid to indicating metabolic changes in bladder cancer tissues that are potentially correlated with FDFT1 expression.

Mohammed Alsufayan, Abdelmoneim Sulieman, Rayan Moslem, Abdullah Asiri, Abdullah Alomary, Bandar M. Alanazi, Hassan Aldossari, Batil Alonazi, David A. Bradley (2021)Assessment of imaging protocol and patients radiation exposure in computed tomography colonography, In: Applied sciences11(11) Mdpi

In the screening and identifying of colon and rectum malignancy, computed tomography colonography (CTC) is a highly effective imaging technique, albeit patients receiving a significant effective dose. Accordingly, patient dose evaluation is an important need, seeking to ensure benefits outweigh the projected cancer risk. Objective: For CTC procedures carried out in the Radiology Department, Medical Imaging Operation Services, King Fahad Medical City (KFMC), evaluation is done using the current American College of Radiology (ACR) imaging protocol and concomitant patient-effective doses. Study is carried out on a sample size of 55 CTC procedures, involving 25 males (45%) and 30 females (55%). The patients were classified as follows: two groups based on CT machine; four groups based on the applied protocol; and three groups based on the procedure results. All procedures were carried out using two machines, the products of two different vendors (a GE Healthcare DISCOVERY CT 750 HD 64 slices dual-energy scanner and a Philips Brilliance CT 64 slices scanner). The overall mean, standard deviation (SD), median, and range of the effective dose (in mSv) were 11.57 +/- 7.75, 9.25 (2.17-31.93). Automatic tube current modulation (ATCM) shows a significant increase in CTDIvol up to 69% and effective dose (mSv) up to 95% than the manual tube current (mA) compared to the standard protocol. The CT protocol variation results in a three-fold variation in patient-effective dose. The technologist role is crucial in selecting a noise reference based on patient weight and adjusting tube current per slice to avoid overexposure during ATCM protocol.

Muhammad Riaz, Amrina Suleman, Pervaiz Ahmad, Mayeen Uddin Khandaker, Amal Alqahtani, David A. Bradley, Muhammad Qayyum Khan (2022)Biogenic Synthesis of AgNPs Using Aqueous Bark Extract of Aesculus indica for Antioxidant and Antimicrobial Applications, In: Crystals (Basel)12(2) Mdpi

Nanotechnology has received a lot of attention from the scientific community because of the greater surface-to-volume ratio of nanomaterials, which phenomenally increases their efficacy in practical applications. Among the various synthesis techniques, the biogenic or green synthesis of nanomaterials shows advantages over other techniques such as physical, chemical, etc. This study reports the biogenic synthesis of silver nanoparticles (AgNPs) using aqueous bark extract of Aesculus indica. The as-synthesized NPs were characterized by UV-visible, FT-IR, XRD, and SEM, and then tested for their antioxidant and antimicrobial potency. We have identified phenols, flavonoids, tannins, saponins, and carbohydrates in the bark extract of A. indica. The extract-loaded-AgNPs showed the highest inhibition for Staphylococcus aureus (28.0 mm), Pseudomonas aeruginosa (17.66 mm), Escherichia coli (14.33 mm), Acetobacter serratia (14.00 mm), and Klebsiella pneumoniae (12.33 mm). The methanolic bark extract inhibited S. aureus (24.33 mm), P. aeruginosa (10.66 mm), E. coli (11.33 mm), A. serratia (9.66 mm), and K. pneumoniae (11.66 mm). Aqueous bark extract inhibited S. aureus (22.33 mm), P. aeruginosa (8.33 mm), E. coli (9.33 mm), A. serratiaa (8.33 mm), and K. pneumoniae (9.66 mm). Its aqueous extract showed the highest antioxidant potency; IC50 (0.175 mu g/mL) followed by the methanolic extract; IC50 (0.210 mu g/mL) and extract-loaded nanoparticles; IC50 (0.901 mu g/mL). Our findings provide meaningful interest for antioxidant, anti-microbial applications of, and AgNPs synthesis by, aqueous bark extract of A. indica.

Siti Norbaini Sabtu, S. F. Abdul Sani, D. A. Bradley, L. M. Looi, Z. Osman (2020)A review of the applications of Raman spectroscopy for breast cancer tissue diagnostic and their histopathological classification of epithelial to mesenchymal transition, In: Journal of Raman spectroscopy51(3)pp. 380-389 Wiley

Breast cancer is one of the leading cancers in women worldwide. Notwithstanding the clear advances being made in treatment, early diagnosis of the disease can certainly be expected to reduce morbidity and mortality. With increasing evidence of the role of epithelial to mesenchymal transition (EMT) in tumour progression, early detection of this phenomenon is suggested to be important given that the majority of breast cancer deaths are due to tumour invasion and metastasis. Although histopathology and biomedical imaging techniques continue to be used as standard procedures in breast cancer diagnosis, these techniques have a number of disadvantages, including being time-consuming, the imaging in particular having attendant limited resolution, sensitivity, and specificity, leading to results that are prone to errors in human interpretation. Due to its rapidity and high specificity, Raman spectroscopy has emerged as a diagnostic tool for breast cancer, useful in identifying malignancy of breast cells, correlated with the EMT phenotype, expressed at the molecular level. Detailed biochemical information from tissue biopsies can also be provided from use of this technique. The use of Raman spectroscopy in breast cancer investigations over the past 10 years and more, including in the study of EMT, is reviewed in the present work also listing the corresponding Raman peaks reported in the literature in seeking to better facilitate identification of peaks of interest.

M. M. Mahfuz Siraz, Debasish Roy, Md. Jafor Dewan, M. S. Alam, A. M. Jubair, Md. Bazlar Rashid, Mayeen Uddin Khandaker, D. A. Bradley, S. Yeasmin (2023)Vertical distributions of radionuclides along the tourist-attractive Marayon Tong Hill in the Bandarban district of Bangladesh, In: Environmental monitoring and assessment195(3)pp. 382-382 Springer Nature

This is the first attempt in the world to depict the vertical distribution of radionuclides in the soil samples along several heights (900 feet, 1550 feet, and 1650 feet) of Marayon Tong hill in the Chittagong Hill Tracts, Bandarban by HPGe gamma-ray spectrometry. The average activity concentrations of Th-232, Ra-226, and K-40 were found to be 37.15 +/- 3.76 Bqkg(-1), 19.69 +/- 2.15 Bqkg(-1), and 347.82 +/- 24.50 Bqkg(-1), respectively, where in most cases, Th-232 exceeded the world average value of 30 Bqkg(-1). According to soil characterization, soils ranged from slightly acidic to moderately acidic, with low soluble salts. The radium equivalent activity, outdoor and indoor absorbed dose rate, external and internal hazard indices, external and internal effective dose rates, gamma level index, and excess lifetime cancer risk were evaluated and found to be below the recommended or world average values; but a measurable activity of Cs-137 was found at soils collected from ground level and at an altitude of 1550 feet, which possibly arises from the nuclear fallout. The evaluation of cumulative radiation doses to the inhabitants via periodic measurement is recommended due to the elevated levels of Th-232.This pioneering work in mapping the vertical distribution of naturally occurring radioactive materials (NORMs) can be an essential factual baseline data for the scientific community that may be used to evaluate the variation in NORMs in the future, especially after the commissioning of the Rooppur Nuclear Power Plant in Bangladesh in 2024.

Siti Norbaini Sabtu, S F Abdul Sani, L M Looi, S F Chiew, Dharini Pathmanathan, D A Bradley, Z Osman (2021)Indication of high lipid content in epithelial-mesenchymal transitions of breast tissues, In: Scientific reports11(1)pp. 3250-3250

The epithelial-mesenchymal transition (EMT) is a crucial process in cancer progression and metastasis. Study of metabolic changes during the EMT process is important in seeking to understand the biochemical changes associated with cancer progression, not least in scoping for therapeutic strategies aimed at targeting EMT. Due to the potential for high sensitivity and specificity, Raman spectroscopy was used here to study the metabolic changes associated with EMT in human breast cancer tissue. For Raman spectroscopy measurements, tissue from 23 patients were collected, comprising non-lesional, EMT and non-EMT formalin-fixed and paraffin embedded breast cancer samples. Analysis was made in the fingerprint Raman spectra region (600-1800 cm ) best associated with cancer progression biochemical changes in lipid, protein and nucleic acids. The ANOVA test followed by the Tukey's multiple comparisons test were conducted to see if there existed differences between non-lesional, EMT and non-EMT breast tissue for Raman spectroscopy measurements. Results revealed that significant differences were evident in terms of intensity between the non-lesional and EMT samples, as well as the EMT and non-EMT samples. Multivariate analysis involving independent component analysis, Principal component analysis and non-negative least square were used to analyse the Raman spectra data. The results show significant differences between EMT and non-EMT cancers in lipid, protein, and nucleic acids. This study demonstrated the capability of Raman spectroscopy supported by multivariate analysis in analysing metabolic changes in EMT breast cancer tissue.

M.T. Chew, B. Jones, M. Hill, D.A. Bradley (2021)Radiation, a two-edged sword: From untoward effects to fractionated radiotherapy, In: Radiation physics and chemistry (Oxford, England : 1993)178 Elsevier Ltd

Radiations in medicine cover a wide range of applications, predominantly in diagnostic imaging and radiotherapy, encompassing photons (x- and γ-rays) and particle radiation, as well as with the use of liquid sources in nuclear medicine focusing on physiological functional imaging, tumour detection or targeted radiotherapy. The biological interactions of ionizing radiation leads naturally to questions of benefits and risk following dose exposures. The inherent properties of ionizing radiation in sterilising dividing cells can offer immense benefits with respect to tumour control, but radiation can also deliver potential harm in the form of normal tissue toxicity or carcinogenesis. The advances in radiation technology, offering accurate and reliable dose delivery, in concert with greater understanding of the underpinning radiobiological effects are creating an ever-growing ability to extract maximum benefit and minimise risk. The radiobiological effects fall broadly under the headings of mutagenesis, chromosomal aberrations, radiation induced genomic instability and cell death. The enormity of evidence derived from these underlie the mechanism of the six Rs of controlled radiotherapy: repair, repopulation, reoxygenation, redistribution, radiosensitivity and most recently, remote bystander cellular effects (including low dose hyper-radiosensitivity, adaptive response, hormesis, abscopal effect and immune response). Herein, we seek to discuss how such understanding leads to optimised radiotherapy. •Radiation in medicine is used primarily for diagnosis and radiotherapy.•Ionizing radiation beneficial and detrimental effects.•The 6 Rs of radiotherapy.

M.M. Mahfuz Siraz, Jubair Al Mahmud, M.S. Alam, Md. Bazlar Rashid, Zakir Hossain, Mayeen Uddin Khandaker, D.A. Bradley, M.M.H. Miah, B. Alshahrani, S. Yeasmin (2023)Risk assessment of naturally occurring radioactivity in soil adjacent to a coal-fired brick kiln, In: Radiation physics and chemistry (Oxford, England : 1993)209 Elsevier Ltd

Being aware of the potential health effects brought on by exposure to radionuclides, besides chemical and air pollution, produced by coal-fired brick kilns, first-ever measurements of terrestrial radionuclides were performed in the topsoil sampled from the surrounding of a randomly chosen coal-fired brick kiln operating at the outskirts of megacity Dhaka, Bangladesh. By employing the HPGe gamma-ray spectroscopy, the activity concentrations of 226Ra, 232Th, and 4 K was found to be in the range of (19.2 ± 2.7–54 ± 7.0) Bq/kg, (33 ± 5.3–68 ± 9.5) Bq/kg, and (360 ± 43–540 ± 65) Bq/kg respectively, where almost all the values of 40 K, 232Th; and some of the values of 226Ra exceeded the corresponding world average values. Possible causes of the elevated level of radionuclides include the deposition of bottom ash in lowlands, the accumulation of fly ash in soils, and the fallout of fine particles that absorb the minerals released from the coal burning process. 137Cs was also found in two samples that might indicate contamination of the feed coal. Most of the outdoor absorbed dose rates, some internal absorbed dose rates, annual effective dose, gamma level index and excess lifetime cancer risk surpass the worldwide average. According to these hazard parameters, there are health risks to the brick kiln workers and the populace who consumes food crops produced in the studied agricultural soils. The present quantitative measurements urge the municipal authorities to manage and monitor the discharge of fly ash from the brick kilns and take precautionary actions to reduce unwanted health hazards. It also demands to monitor of the human health of workers and residents near the brick kilns. •First-ever radionuclide measurement in soil sampled from coal-fired brick kiln.•Elevated 226Ra, 232Th and 40 K activity concentrations were observed.•Most of the radiological hazard parameters surpass the worldwide average.•The outcomes will be used as a radiological baseline data.

Norfadira Binti Wahib, Mayeen Uddin Khandaker, S. F. Abdul Sani, K. S. Al-mugren, D. A. Bradley, A. Sulieman, Mohammad Rashed Iqbal Faruque, M. I. Sayyed (2020)The potential use of car windscreens for post-accident dose reconstruction in the periphery of nuclear installations, In: Applied sciences10(20)pp. 1-14 Mdpi

Cars of a variety of brands are usually parked at a fixed but increasing distance in the periphery of nuclear installations. Herein we focus on the potential use of car windscreens for post-accident dose reconstruction from unplanned nuclear events and natural disasters, also in regard to unexpected events arising during large-scale use of radioactive and nuclear materials. The situation requires identification of analytical techniques that could both readily and reliably be used to assess absorbed dose, sufficient to prompt remedial action where necessary. Samples from three widely used car brands-Honda, Toyota and Proton-are studied in respect of their thermoluminescence (TL) yield. Key TL dosimetric features in the gamma-ray dose range of 1-100 Gy are examined. An ERESCO model 200 MF4-RW X-ray machine has also been used for energy response studies; a Harshaw 3500 TLD reader equipped with WinREMS software was used for the luminescence measurements. All brands exhibit linearity of TL yield versus dose, the samples from Honda showing the greatest response followed by that of the Toyota and Proton brands. The marked energy dependence reflects the effect of the strongly Z-dependent photoelectric effect. Signal fading was investigated over a period of 28 days, the Toyota and Proton brand windshield glass showing a relatively low loss at 52.1% and 52.6% respectively compared to a 56.7% loss for that of the Honda samples. This work forms the first such demonstration of the potential of car windshield glass as a retrospective accident dosimeter.

A. Sulieman, A. Abdelrazig, H. Al-Mohammed, M. Alkhorayef, B. Alonazi, I. I. Suliman, N. Abuhadi, D. Bradley (2020)Radiogenic risks to patients and staff from fluoro-assisted therapeutic cardiac catheterizations, In: Radiation physics and chemistry (Oxford, England : 1993)167 Elsevier

Advances in sectional imaging have led to prolonged x-ray fluoro-assisted therapeutic cardiac catheterizations. Given the frequency of such procedures, limited data are available for patient and staff doses. For certain pediatric cardiac catheterization procedures we examine: (i) effective and organ doses, also the radiogenic and tissue reaction risks and; (ii) staff effective dose during cardiac interventions. At four cardiac catheterization centres, patient doses were measured with a calibrated kerma area product (KAP) meter; staff doses were measured using calibrated TLDs. The mean and range of age (years) and weight (kg) for patients were 4.3 (0.04-14.0) and 10.8 (3.0-46.0) respectively; the overall mean and range of fluoroscopic time (min) was 13.0 (1.4-54.8). For coronary angiography and pacemaker procedures the overall mean and range of cumulative kerma area product (CRAP, cGy.cm(2)) were 350 (12.0-510). The average annual staff dose of 9.0 (7.2-14.4) mSv is relatively low given the current workload. Some patients received high doses approaching the threshold for tissue reactions. Optimisation of radiation dose is required as is follow-up of patients receiving high doses to detect the possibility of tissue reactions.

W. Elshami, M.M. Abuzaid, M.M. Gibril, A. Sulieman, D.A. Bradley (2022)Impact of high kilo-voltage peak technique on radiation dose for neonates undergoing chest radiography: Experimental study, In: Radiation physics and chemistry (Oxford, England : 1993)199 Elsevier Ltd

Chest radiography remains the most often utilized radiological modality in the neonatal intensive care unit. Neonates are more radiosensitive and are at higher risk of cancer than adults. In addition, they have a longer life expectancy, which increases the risk of cancer. Therefore, it is essential to protect neonates from radiation hazards. The study aims to assess the effectiveness of using high HKVp technique on reducing radiation dose to neonates undergoing Antero-posterior (AP) chest x-rays. The experiment used a newborn anthropomorphic phantom to simulate a neonate. Chest x-ray images were acquired using different combinations of KVp and mAs. Dose area product (DAP) was recorded in the Digital Imaging and Communications in Medicine (DICOM) header. The effective dose was determined using Monte Carlo simulation. Subjective assessment of image quality was evaluated by three radiologists blindly. The Objective assessment of image quality uses the calculation of the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR). The reduction in the DAP and effective dose at 50 KVp was 26.7% and 19.2%, respectively and for 60 KVp it was 22.9 and 20.2, respectively. While, the reduction in the DAP and effective dose at 70 KVp was 40% and 26%, respectively. There were no significant differences in the means of the DAP, SNR, CNR, and effective dose among different combinations of KVp and mAs. The use of the high KVp technique can play an important role in reducing radiation dose without significant loss of image quality. •Use of the high KVp technique can reduce radiation dose without significant loss of image quality.•At 70 KVp, the DAP and effective dose reduced by 40% and 26%, respectively.•Use of high kVp showed no significant difference in SNR, CNR and radiation dose.•Effort should be made to reduce patients' dose without compromising diagnostic outcome.

Ali Aamry, Abdelmoneim Sulieman, N. Tamam, Nouf H. Abuhadi, Yehia Johary, Hussin Aamri, E. Mattar, Hassan Salah, Hamid Osman, Mayeen Uddin Khandaker, David Bradley (2022)Evaluation of the annual occupational effective doses in a SPECT/CT department, In: Applied radiation and isotopes181pp. 110097-110097 Elsevier Ltd

Staff occupational radiation exposure is limited to 20 mSv annually to preclude tissue reaction and lower risk of cancer effect. Staff occupational exposure arises during the preparation, injection, and scanning of the patients. Recent studies reported that nuclear medicine personnel might exceed the annual dose limit in high workload and poor radiation protection circumstances. Therefore, an accurate estimation of the annual dose limit is recommended. The goal of this research is to calculate the cumulative external effective dose (mSv) per year for nuclear medicine physicians, technologists, and nurses at SPECT/CT department. A total of 15 staff worked in the nuclear medicine department at King Saud Medical City (KSMC), Riyadh, Saudi Arabia were evaluated for the last six years. 99mTc is used more frequently for most of the patients. The procedures include renal, cardiac scintigraphy procedures. Staff dose was quantified using calibrated thermoluminecnt dosimeters (TLD-100) with an automatic TLD reader (Harshaw 6600). Exposure to ionizing radiation was evaluated in terms of deep doses (Hp(10) were evaluated. The overall average and standard deviation of the external doses for nuclear medicine physicians, technologists' and nurses were 1.8 ± 0.7, 1.9 ± 0.6, 2.0 ± 0.9, 2.2 ± 0.8, 6.0 ± 2.8, and 3.6 ± 1.3 for the years 2015,2016,2017,2018,2019, and 2020, respectively. Technologists and nurses received higher doses of compared to the nuclear medicine physicians. Technologists and nurses involved in radionuclide preparation, patients' injection, and image acquisition. Staff annual exposure is below the annual dose limits; however, this external dose is considered high compared to the current workload. •Staff annual effective dose was estimated at nuclear medicine department equipped with two SPECT/CT systems.•External effective dose in terms of Hp(10) was monitored for six consecutive years.•Occupational exposure was quantified with thermoluminecnt dosimeters (TLD-100).•Technologists and nurses received higher doses than the nuclear medicine physicians.•Staff annual radiation from external exposure is 50% below the annual dose limits.

Nissren Tamam, H. Salah, Mohammad Rabbaa, Mohammad Abuljoud, A. Sulieman, M. Alkhorayef, D. A. Bradley (2021)Evaluation of patients radiation dose during mammography imaging procedure, In: Radiation physics and chemistry (Oxford, England : 1993)188 Elsevier

This study investigates patients' dose levels during digital mammography procedures and proposes a local diagnostic reference level (DRL). The patient sample is 1055 patients who have been examined at the Riyadh Care Hospital, Riyadh, Saudi Arabia. All procedures were carried out for medically justified clinical conditions. All procedures were carried out using a direct digital mammography (DDR) radiology system. The mean and range of ESAK (mGy) were 5.19 +/- 3.18 (0.33-29.9), while the mean AGD (mGy) is 1.3 +/-(1.0-7.2) per procedure. The third quartile value for ESAK (mGy) and AGD (mGy) is 6 and 1.5, respectively. Measured ESAK (mGy) per procedure and estimated AGD are comparable with previous studies. The interpatient and interdepartmental variation is attributed mainly to the number of projections per procedure.

Noor Zati Hani Abu Hanifah, Suhairul Hashim, Halmat Jalal Hassan, Nur Nabihah Yusof, D.A. Bradley (2021)Radioactive material in cosmetic and healthcare products: Regulatory controls, In: Radiation physics and chemistry (Oxford, England : 1993)188 Elsevier Ltd

We provide an overview of the issue of the regulatory control of cosmetics and healthcare products that intentionally contain added radioactivity, the suggested health benefits from such product utilisation being firmly within the realm of the unproven. Examples are offered of control practices in several countries. Access to the products depends strongly on national controls. This apart, there is a general lacking in public awareness of such radioactive content and the potential for harm in the circumstance of daily exposure to such media. With prolonged use of these adding to cancer risk, at the manufacturing stage it is suggested that the products should be subject to regulatory inspection and certification, crucial in reducing radiation exposure. In particular, based on published data from a number of European and Asian countries, review is made of such cosmetic and healthcare products, also including estimates of the effective doses implied from the utilisation of these. The information concerns the progeny of the primordial radionuclides 238U, 232Th, and 40K, encompassing a comparatively large range of values, from 1.7×10-4 to 2.8×103 Bq per kg for 238U, 3×10-5 to 1.2×104 Bq per kg for 232Th and 1.1×10-3 to 9.5×102 for 40K. In many countries standards and regulations have been implemented typically with authority over exemptions for radioactive materials in cosmetic and healthcare products. In the absence of harmonised regulations, transnational access and the use of such cosmetic and healthcare products will remain a worldwide concern. •The exemption limits of various national authorities have been reviewed.•The effective dose from use of selected cosmetic and healthcare products assessed.•Call made for global harmonisation in regulation of NORM-added consumer products.

Abdullah Almujally, Nissren Tamam, Abdelmoneim Sulieman, Duong Thanh Tai, Hiba Omer, Nouf Abuhadi, Hassan Salah, Essam Mattar, Mayeen Uddin Khandaker, David Bradley (2022)Evaluation of paediatric computed tomography imaging for brain, and abdomen procedures, In: Radiation physics and chemistry (Oxford, England : 1993)200 Elsevier Ltd

Computed tomography (CT) are often used for adult and pediatric patients. This is basically due to its powerful diagnostic capabilities in providing the tiniest details of pathologies in the body. Nevertheless, this detailed and accurate imaging occurs at the expense of the high doses received by the patients, although in general, the benefits outweighs the risks precisely of malignancy. Pediatrics are radiosensitive more than adults due to their longer life expectancy and their rapidly dividing cells. This study aims at measuring and evaluating pediatric patient doses in four hospitals equipped with 16, 20 and 128 CT detectors. Forty-eight pediatric patients who underwent brain (72.7%) and abdomen (36.3%) Computed Tomography are included in this study. Data includes CTDIvol (mGy) and DLP (mGy.cm). CTDOSE computer software which is based on Monte Carlo simulations was used to calculate the effective and organ equivalent doses (mSv). The CTDIvol (mGy) per procedure range was 11.0–95.0 mGy for brain CT and 3.0–30.0 mGy for abdomen CT. DLP on the other hand ranged between 129.0 and 2510.0 mGy cm for brain CT and 84.0–1604.0 for abdomen CT. The high doses were attributed to the fact that the protocols used for pediatric patients were the adult protocols, not bearing in mind the high radio-sensitivity of the pediatrics. Establishing a protocol for pediatric CT is hence of great importance to prevent them from receiving unnecessary high doses which may eventually cause cancer. •The radiation doses during specific pediatric CT examinations in four hospitals were evaluated.•Patient dose per CT procedure ranged from 84.0 to 2510.0 mGy cm.•Adults protocols used for pediatric patients resulted in unnecessary exposure.•Standardizing imaging protocols during pediatric CT imaging is recommended.

S. Karthikayini, Mefleh S. Hamideen, A. Chandrasekaran, Mayeen Uddin Khandaker, D.A. Bradley (2023)X-ray fluorescence analysis of coastal sediments of Tamil Nadu with a statistical approach, In: Radiation physics and chemistry (Oxford, England : 1993)209 Elsevier Ltd

X-ray fluorescence spectroscopy is applied to determine the concentration of essential and toxic heavy metals such as silicon (Si), potassium (K), calcium (Ca), titanium (Ti), iron (Fe), copper (Cu), zinc (Zn), nickel (Ni), and lead (Pb) in the sediments of Kovalam coastal area, Tamil Nadu, India. Fe (599280 ppm), an essential heavy metal/mineral shows the highest average concentration, followed by Si (181593 ppm), Ca (130913 ppm), K (99673 ppm), Ti (77620 ppm), Cu (64 ppm), Ni (43 ppm), Pb (20 ppm), and Zn (8 ppm). Heavy metal contamination was assessed using various pollution indicators such as the geo-accumulation index (Igeo), contamination factor (CF), pollution load index (PLI), and enrichment factor (EF). Si, K, Ca, Ti, Fe, Cu, Ni, Pb, and Zn had mean Igeo values of −1.29, 1.54, 1.07, 3.59, 3.19, 0.64, −1.14, −0.22, and −3.70, respectively. Except for Ti (19.36) and Fe (13.87), the average CF value for determined heavy metals was significantly low. The PLI value ranges from 1.47 to 2.46. Heavy metal EF values are greater than 1 in all sampling locations. Multivariate statistical analyses such as Pearson correlation analysis, cluster analysis, and principal component analysis are performed to identify the sources of heavy metals in the studied sediment samples. The findings indicate that anthropogenic sources such as boating and tourism activities have a probable contribution on the enrichment of K, Ca, Ti, Fe, Cu, and Pb in sediments, necessitating more attention in monitoring of toxic heavy metals (such as Pb) contamination in the coastal environment. •Concentration of Fe, Si, Ca, K, Ti, Cu, Ni, Pb, Zn was reported for sediments by XRF.•Ti, Fe and K is found to be 19, 13 and 4 times more than the background value.•Statistical methods are applied to identify the metal sources.•Ti, Fe, Ca, Cu and K are derived from anthropogenic activities.

Abdullah Alsubaie, Eman Daar, L. Alsulaiti, Abdullah N. Al-Dabbous, Mariem Chamakh, Maisarah Jaafar, D A Bradley (2020)Reprint of Elemental evaluation of urban road dirt in tropical, arid and maritime climates, In: Radiation physics and chemistry (Oxford, England : 1993)167 Elsevier Ltd

Interest is in vehicular trace elemental contributions to the environment, evaluated via analysis of road dirt. Results from SEM/EDX, ICP-MS and ICP-OES are compared for a wide range of elements. ICP-OES and ICPMS provide absolute quantification while SEM/EDX has provided weight % assessments. Roadside dirt has been sampled along busy campus roads of universities/research centres in Guildford, Riyadh, Kuwait City, Doha and Kuala Lumpur, satisfying interest in climatic influences as well as vehicle engine size (Gulf non-commercial vehicle engine capacities tending to be greater than those in the UK or Malaysia). A total of 100 street dust samples have been analyzed, elemental concentrations being reported for Mg, Al, Ti, Mn, Fe, Co, Zr, Mo, Ba, Tl, V, Rd, Pb, Cu, Zn, Ni, Cr, Cd, As, Hg and Au. For all five urban centres, Al, Fe, Mg, and Si values were found to be well above background while concentrations of Ti, Cr and Ba were lower than values reported by others. Au and Ag from catalytic convertors were found in some centres, albeit at very low concentrations and with particle sizes of the order of 0.5 µm. The various techniques offer complementary information on vehicular emission elemental concentrations in urban environments. •Metal element concentrations investigated in road dirt.•Concentration obtained in urban road dirt in tropical, arid and maritime climates.•Elevated levels Al, Fe, Mg and Si found, less so in tropical and maritime roads than in the arid zones.•The concentrations of Mg show greater elevations in a few of the Doha locations.

Hassan Salah, Fareed H. Mayhoub, A. Sulieman, M. Abuzaid, H. I. Al-Mohammed, M. Alkhorayef, D. A. Bradley (2020)Fluoro-D-glucose (18F-FDG) PET/CT and patient effective dose, In: Radiation physics and chemistry (Oxford, England : 1993)173 Elsevier

In the present study, patient exposures Evaluations herein concern patient exposures (positron and gamma-rays) that result from fluoro-D-glucose PET and CT were investigated and radio-carcinogenic risks estimated. The six-month study, conducted at King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia, included a total of 636 patients (lymphoma = 187, nasopharyngeal carcinoma = 82, thyroid = 30 and others = 337). Patient effective dose estimations were made from administered radioactivity (AA) and CT exposures (General Electric (GE) PET/CT VCT), the mean and range of AA (in MBq) and effective dose (in mSv) were respectively: lymphoma 433.9 +/- 70.6 (297.5-735.9) and 8.2 +/- 1.3 (5.7-13.9); nasopharyngeal carcinoma 417.7 +/- 55.9 (325.6-547.6) and 7.9 +/- 1.1 (6.2-10.4); thyroid 450.1 +/- 71.4 (344.1-566.1) and 8.6 +/- 1.4 (6.5-10.8). In the same units, the mean and range of AA and effective dose for other procedures were 421.6 +/- 58.3 (283.4-606.8) and 8.0 +/- 1.1 (5.4-11.5), respectively. The mean and range of the tube current-time product (mAs) for the CT procedures were 30 (8.2-42.4). A constant tube voltage of 120 kVp was used for all patient procedures. On average, CT contributed 73% to patient effective doses, suggesting that optimisation of CT acquisition parameters are vital in seeking effective dose reduction. Patient effective doses were found to be a little above that of previous studies.

Layal Jambi, Mohammed Alkhorayef, Mohammed Almuwanis, Hiba Omer, Nazar Alhasan, Duong Thanh Tai, Abdelmoneim Sulieman, David Bradley (2022)Assessment of the effective radiation dose and radiogenic effect in intravenous urography imaging procedures, In: Radiation physics and chemistry (Oxford, England : 1993)200 Elsevier Ltd

The pathology of the urinary system is usually investigated using Intravenous Urography (IVU). The study objectives are to quantify patients’ radiation dose and radiation induced malignant tumors risk during IVU examination. The radiation doses during IVU and the subsequent risks from exposure are studied, using data from 50 patients imaged in one hospital. The demographic data given as (mean ± std) was as follows:The age of patients was 39 ± 14 years; height of patients was 1.7 ± 0.1 m, the mass was 69 ± 10 kg and the body-mass-index was 24.3 ± 4.1 kg m−2. The physical exposure parameters recorded were: kVp: 74.04 ± 3.1, mAs: 33.64 ± 4. Moreover, the average number of films per procedure was 5.72 ± 1.49. The entrance-surface air kerma (ESAK) was 2.1 ± 0.64 mGy, and the mean effective dose was 0.131 ± 0.04 mSv. Calculation of the overall cancer risk yielded 5.9 × 10−6 procedures. ESAK (mGy) and effective dose values obtained in this study were comparable with reported studies as shown in the text. The effective and cancer risk are around ten times lower during IVU procedures than for example, contrast enhanced computed tomography urography (CTU) examination. Reduction of doses received by patients to meet the values of the diagnostic reference levels without compromising the quality and clarity of the images is highly recommended. Radiation dosimetry; IVU; Radiology; Cancer risk; medical imaging. •The radiation doses during IVU and the subsequent risks from exposure are studied.•The entrance-surface air kerma (ESAK) and effective dose were quantified.•Calculation of the overall cancer risk yielded 5.85 per million procedures.•Patients received higher doses due to unoptimized imaging protocol.

H Salah, Nissren Tamam, Mohammad Rabbaa, Mohammad Abuljoud, Ali Zailae, Alkhorayef, N Abuhadi, W Elshami, A Sulieman, D A Bradley (2023)Assessment of patients radiation doses associated with computed tomography coronary angiography, In: Applied radiation and isotopes192pp. 110548-110548

Computed tomography coronary angiography (CTCA) has generated tremendous interest over the past 20 years by using multidetector computed tomography (MDCT) because of its high diagnostic accuracy and efficacy in assessing patients with coronary artery disease. This technique is related to high radiation doses, which has raised serious concerns in the literature. Effective dose (E, mSv) may be a single parameter meant to reflect the relative risk from radiation exposure. Therefore, it is necessary to calculate this quantity to point to relative radiation risk. The objectives of this study are to evaluate patients' exposure during diagnostic CCTA procedures and to estimate the risks. Seven hundred ninety patients were estimated during three successive years. The patient's exposure was estimated based on a CT device's delivered radiation dose (Siemens Somatom Sensation 64 (64-MDCT)). The participating physicians obtained the parameters relevant to the radiation dose from the scan protocol generated by the CT system after each CCTA study. The parameters included the volume CT dose index (CTDIvol, mGy) and dose length product (DLP, mGy × cm). The mean and range of CTDIvol (mGy) and DLP (mGy × cm) for three respective year was (2018):10.8 (1.14-77.7) and 2369.8 ± 1231.4 (290.4-6188.9), (2019): 13.82 (1.13-348.5), and 2180.5 (501.8-9534.5) and (2020) 10.9 (0.7-52.9) and 1877.3 (149.4-5011.1), respectively. Patients' effective doses were higher compared to previous studies. Therefore, the CT acquisition parameter optimization is vital to reduce the dose to its minimal value.

Musa Joya, Zabihullah Stanikzai, Isa Akbarzadeh, Somayyeh Babaloui, David.A. Bradley, Shakardokht M. Jafari (2020)Prevalence of cancers diagnosed in Jamhuriyat Hospital, Kabul, Afghanistan, In: Heliyon6(3)pp. e03603-e03603 Elsevier Ltd

Throughout the world, there exists a clear need for the maintenance of cancer statistics, forming an essential part of any rational programme of cancer control, health-care planning, etiological research, primary and secondary prevention, benefiting both individuals and society. The present work reports only on the prevalence of cancers in the Oncology Department of Jamhuriyat Hospital, Kabul, Afghanistan following several decades of war. A quantitative retrospective cross-sectional study was conducted using the medical records of patients diagnosed and treated from October 2015 to December 2017. Data includes information on gender, age, economic status, address and types of cancer diagnosed. The data was transferred to a customized form and analysed using Microsoft Excel program to classify cancer types. The total number of patients with completed documents were 1025. Of these, 403 (39.3%) were male and 622 (60.7%) female. Most of the patients were in the age range of 20–70 years old. The most common cancers in women were breast cancer (45.8%), followed by oesophagus (12.5%), colorectal (4.8%), Non-Hodgkin Lymphoma (4.7%), sarcoma (4.7%), ovary (3.8%), both stomach and liver (2.6%) and cervix uteri (1.9%). Contrarily to men, esophageal cancer was highest (21.8%), followed by stomach (12.2%), Non-Hodgkin Lymphoma (9.4%), sarcoma (8.9%), gastroesophageal junction (8.9%), colorectal (8.6%), Hodgkin lymphoma (4.7%), testis (4.2%), liver (3.2%), lung (2.7%) and Nonmelanoma skin squamous cell carcinoma 9 (2.2%). Results showed that the most frequent cancers among Afghans were breast and oesophagus. The most common cancer in men was oesophagus and stomach at the age range of 50–70 years while in women, breast and oesophagus cancers were common and within the age range of 25–65 years old. Cancer research; Epidemiology; Public health; Oncology; Women's health; Oncology; Afghanistan; Cancer prevalence; Kabul Jamhoriyat hospital.

Rasha Jaafar, Abdelmoneim Sulieman, Nissren Tamam, Hiba Omer, Abdelrahman Elnour, Ali Alhailiy, Mohammed Alkhorayef, Mayeen Uddin Khandaker, D.A. Bradley (2021)Multiphase vascular lower limb computed tomography: Assessment of patients doses and radiogenic risk, In: Radiation physics and chemistry (Oxford, England : 1993)188 Elsevier Ltd

The purposes of this study are to estimate patient's radiation doses and radiogenic risk in vascular lower limb computed tomography (CT). In total, 188 (109 (68%) males and 79 (42%) females) patients undergone vascular CT for the lower limbs at three radiology departments. Three CT scanners, 160, 128, and 64 slices CT, were used in this study. CT-Expo and ImPACT CT dose estimation software were used to extrapolate the effective dose. The overall average and range of volume CT dose index (CTDIvol (mGy) and dose length product (DLP) (mGy.cm) 7.3 (2.3–22.9), and 3000 (279.1–8374.4) the same order. The overall effective dose average value was 18 mSv per procedure. The proposed diagnostic reference level (DRL) values are 9 mGy (CTDIvol) and 2500 mGy cm (DLP) per vascular lower limb CT procedure. The risk of cancer from the peripheral CT angiography procedures ranges from 1 in 1000 to 1 in 3000 procedures. The cancer risk per procedure should be considered during the justification and image acquisition stages. •Peripheral CT angiography for lower extremities were performed using three CT machines.•CT dose per procedure (DLP (mGy.cm) is higher up to 10 times compared to previous.•Patients are being seen to be receiving unnecessary radiation doses during triphasic CT abdomen procedure.•A local diagnostic reference level was proposed was established for further dose reduction.

Duong Thanh Tai, Truong Thi Hong Loan, Abdelmoneim Sulieman, Nissren Tamam, Hiba Omer, David A. Bradley (2021)Measurement of neutron dose equivalent within and outside of a linac treatment vault using a neutron survey meter, In: Quantum beam science5(4) Mdpi

This work concerns neutron doses associated with the use of a Siemens Primus M5497 electron accelerator, which is operated in the photon mode at 15 MV. The conditions offer a situation within which a fraction of the bremsstrahlung emission energies exceed the photoneutron threshold. For different field sizes, an investigation has been made of neutron dose equivalent values at various measurement locations, including: (i) At the treatment table, at a source-surface distance of 100 cm; (ii) at the level of the floor directly adjacent to the treatment table; and (iii) in the control room and patient waiting area. The evaluated neutron dose equivalent was found to range from 0.0001 to 8.6 mSv/h, notably with the greatest value at the level of the floor directly adjacent to the treatment couch (8.6 mSv/h) exceeding the greatest value on the treatment table (5.5 mSv/h). Low values ranging from unobservable to between 0.0001 to 0.0002 mSv/h neutron dose were recorded around the control room and patient waiting area. For measurements on the floor, the study showed the dose equivalent to be greatest with the jaws closed. These data, most particularly concerning neutron distribution within the treatment room, are of great importance in making steps towards improving patient safety via the provision of protective measures.

S. F. Abdul Sani, M. K. Muhamad Azim, A. A. Marzuki, M. U. Khandaker, K. S. Almugren, E. Daar, F. H. Alkallas, D. A. Bradley (2022)Radioactivity and elemental concentrations of natural and commercial salt, In: Radiation physics and chemistry (Oxford, England : 1993)190 Elsevier

Salt (NaCl) has importance not only in regard to the seasoning and preservation of food but also in greater mass utilisation settings, including the salting of roads in wintery conditions. The assessment of health benefits and risk from the intake of salt is of paramount importance, well appreciated in regard to hypernatremia and hypertension but much less considered within the content of natural radioactivity and heavy metals contamination. Present study examines the elemental and radionuclide concentrations of commonly used artificial salts in Malaysia, including Himalayan salt, table salt and Dead Sea cooking salt along with the natural Jordan Dead Sea salt, employing the techniques of Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and High Purity Germanium (HPGe) gamma-ray spectrometry. Measured data have been compared with international advisory limits, as provided by the World Health Organization (WHO) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Individual health risk assessment has been couched in terms of committed effective dose per year from the radionuclides U-238, Th-232, K-40, resulting from the consumption of the various salt inputs. This has led to an upper estimate for terrestrial radionuclide exposure radiation dose to individuals of some 17.1 mu Svy(-1), with an average of 4.3 mu Svy(-1), the latter some 70 times lower compared to the UNSCEAR reference annual advisory dose limit of 290 mu Sv (corresponding to the typical allowable limit for public exposures of 1 mSvy(-1)), representing negligible risk. With respect to heavy metals, the estimated daily intake (EDI) due to the consumption of salts shows the investigated salt samples to all be within the tolerable daily intake (TDI) as guided by the WHO, thereby posing inappreciable toxicity to human health.

H. S Poh, M. C Lee, S. S Yap, S. Y Teow, D. A Bradley, S. L Yap (2020)Potential use of plasma focus radiation sources in superficial cancer therapy, In: Japanese Journal of Applied Physics59(SH) IOP Publishing

The new multidisciplinary field of plasma medicine combines plasma physics, electrical engineering, life sciences and clinical medicine. Bekeschus et al. [Plasma Processes Polym. 16, 1800033 (2019)]. Here we explore potential uses in medicine, most particularly cancer therapy, the plasma source being brought out of the field of industrial applications into the life sciences, the focus being on superficial cancer radiotherapy strategies. Existing radiotherapy practices for such cancers rely on the use of rather large facilities, most popularly the electron linear accelerator and X-ray tube-based devices. Conversely, a compact plasma radiation source can be housed in a relatively small space, there being considerable promise for such devices to produce the fluence requirements of radiotherapy for treatment of skin cancers. The present study of feasibility investigates the plasma focus device, with the emission produced by a single discharge shown to generate an X-ray dose of few tens of mGy. The X-ray dose is the integration of emission in the discharge durations of less than a s, it is therefore possible using these devices to build up fractional irradiation dose through repetitive operation of the discharge system.

Abdelmoneim Sulieman, Hussein Adam, M. Z. Mahmoud, O. Hamid, Mohammed Alkhorayef, David A. Bradley (2020)Radiogenic risk assessment for abdominal vascular computed tomography angiography, In: Radiation physics and chemistry (Oxford, England : 1993)168 Elsevier

Computed tomography (CT) has become a prominent source of medical exposures, conduct requiring measures that mitigate radio carcinogenic risk and deterministic tissue reaction effects. The objective of present study, conducted in Sudan, has been to evaluate patient radiogenic risk during vascular CT procedures. Study was made of 485 patients, the cohort comprising 218 males (45%) and 267 females (55%) of mean age +/- 1 s.d. of 48.2 +/- 17 years (ranging from 18.0 to 93.0 years). The investigation involved nine radiology departments, covering three different CT modalities (16, 64 and 128 slice). Patient organ and effective doses were estimated using established computer software (specifically, CT-Expo, ImPACT and that of the NRPB). The range of patient dose in terms of dose length product (DLP) (mGy.cm) and volume CT dose index (CTDIvol (mGy) were 3.2-28.51 mGy and 257.0-9263.5, respectively. The mean and range of effective dose were 25.5 +/- 18 mSv and 4.0-138.9 mSv respectively. The wide range of doses indicates the likelihood that patients have been receiving avoidable radiation exposure, their being potential for mitigation of cancer incidence risk through further optimisation of procedures. On the basis of present study of vascular CT procedure doses, the mean risk of carcinogenesis has been estimated to be 1 in 1000 procedures.

Mayeen Uddin Khandaker, Mehdi Hassanpour, Saeedeh Khezripour, Mohammad Reza Rezaei, Atefeh Bazghandi, Marzieh Hassanpour, Mohammad Rashed Iqbal Faruque, D.A. Bradley (2023)Investigation of the effect of 131I on blood parameters for thyroid cancer treatment, In: Radiation physics and chemistry (Oxford, England : 1993)208 Elsevier Ltd

Hematopoiesis plays a significant role in mammals' life. Hematopoietic damage due to radiations of different arrays, such as ionizing and non-ionizing radiations, could lead to external infections, internal infections, and anemia. Different cancers' treatment using radioactive sources affects the blood parameters (i.e., mature cells, immature cells, and stem cells). In the present paper, the effect of intravascular injection of Iodine-131 (131I) on the blood parameters for thyroid cancer treatment has been investigated utilizing the MCNPX code and Runge-Kutta fourth-order method. The simulation results showed that the accumulated absorbed dose in adult phantom (ORNL whole body phantom) due to normalized intravascular injection of 1 mCi (mCi) of 131I was 1.97 × 10−2 Sv. Based on the accumulated absorbed dose, the blood parameters show a function of injected 131I activity, and their variation in the activity range of 15–300 mCi was calculated using the fourth-order Runge-Kutta method. It shows that injecting 131I with an activity of less than 150 mCi does not have much effect on blood parameters in the period of two to eight days. But, the injection of 131I with an activity greater than 150 mCi and up to a maximum value of 300 mCi, reduces blood parameters by a maximum of 21.21% in a period of two to eight days. Based on the smaller variation (in percent) of blood parameters due to the injection of low activity 131I (

A Sulieman, H Adam, A Elnour, N Tamam, A Alhaili, M Alkhorayef, S Alghamdi, Mayeen Khandaker, D A Bradley (2021)Patient radiation dose reduction using a commercial iterative reconstruction technique package, In: Radiation physics and chemistry (Oxford, England : 1993)178 Elsevier BV

With 75.4% of the effective doses from imaging estimated to result from computed tomography (CT), it is the leading source of medical radiation. This important observation links with a further estimate that some 2% of all cancers are a result of medical imaging exposures. Acknowledging justification and optimization to be key towards preventing unnecessary radiation exposure, present study aims to investigate radiation exposures reduction for patients undergoing multiphase CT abdomen. Study was made of 111 CT examinations, use being made of two imaging protocols. Of these cases, 55 (49.5%) were obtained using a standard imaging protocol, the remainder being studied using the pure 3D SureExposure™ low-dose technique to obtain a complete abdomen multi-phase examination. Image quality was the subject of blind analysis by two experienced radiologists. For the standard imaging protocol, the mean and standard deviation for CTDIvol and DLP were respectively 7.2 ± 2.3 mGy and 1325 ± 605 mGy cm. For the pure 3D SureExposure™ low-dose technique the respective values were 5.2 ± 1.6 mGy and 812 ± 157 mGy cm. With an achieved mean dose reduction of up to 48%, use of the low dose techniques offers appreciable potential for dose saving without affecting the image quality.

M.J. Abedin, M.R. Karim, Mayeen Uddin Khandaker, M. Kamal, S. Hossain, M.H.A. Miah, D.A. Bradley, M.R.I. Faruque, M.I. Sayyed (2020)Dispersion of radionuclides from coal-fired brick kilns and concomitant impact on human health and the environment, In: Radiation physics and chemistry (Oxford, England : 1993)177 Elsevier Ltd

Realizing the probable health implications via the exposures to radionuclides released from coal-fired brick kilns, concentrations of terrestrial radionuclides in feed coal, fly- and bottom ash collected from some major coal-fired brick kilns of Southern region in Bangladesh were measured using HPGe γ-ray spectrometry. Respective mean activity concentrations (Bq kg−1) for 226Ra, 232Th and 40K were found to be 36.3 ± 1.8, 26.2 ± 2.1 and 314 ± 18 in feed coal; 60.8 ± 3.9, 36.6 ± 3.9 and 338 ± 19 in fly ash; 54.9 ± 4.0, 39.7 ± 4.6 and 311 ± 18.0 in bottom ash samples. As a result of the combustion process, radionuclide concentration enhancements have been observed in proceeding from feed coal to fly- and bottom-ash. The calculated values of air absorbed dose-rates for fly- and bottom-ash are greater than the world average of 55 nGy/h reported by UNSCEAR, and the Lifetime Cancer Risk (LCR) approaches towards the safe limit recommended by the ICRP. As such, this does flag up a potential concern for those dwelling in nearby areas, especially for the coal workers who normally do not take any protective measures against exposure to ash dust. Multivariate statistical analysis has been used in examining for correlations between the origins of the radionuclides and their influence on the calculated radiological parameters. The measured data indicate significance for human health, also for the scientific community, and could be used for modeling studies in the region. •Coal fired brick kilns release terrestrial radionuclides via inhalable ash particles.•Prolonged inhalation of smoke/ash gives rise enhanced radiation exposure to lungs.•Hazardous level of absorbed dose and carcinogenic risk were found for exposed population•Respiratory protection of kiln workers and members of public is highly recommended for radioprotection reasons.•This study suggests the discharging management of fly ash should be revised significantly.

Md.Refat Jahan Rakib, Y. N. Jolly, Diana Carolina Dioses-Salinas, Carlos Ivan Pizarro-Ortega, Gabriel Enrique De-la-Torre, Mayeen Uddin Khandaker, Abdullah Alsubaie, Abdulraheem S. A. Almalki, D. A. Bradley (2021)Macroalgae in biomonitoring of metal pollution in the Bay of Bengal coastal waters of Cox s Bazar and surrounding areas, In: Scientific reports11(1)pp. 20999-20999 Nature Publishing Group UK

Although coastal water marine algae have been popularly used by others as indicators of heavy metal pollution, data within the Bay of Bengal for the estuarine Cox’s Bazar region and Saint Martin’s Island has remained scarce. Using marine algae, the study herein forms an effort in biomonitoring of metal contamination in the aforementioned Bangladesh areas. A total of 10 seaweed species were collected, including edible varieties, analyzed for metal levels through the use of the technique of EDXRF. From greatest to least, measured mean metal concentrations in descending order have been found to be K > Fe > Zr > Br > Sr > Zn > Mn > Rb > Cu > As > Pb > Cr > Co. Potential toxic heavy metals such as Pb, As, and Cr appear at lower concentration values compared to that found for essential mineral elements. However, the presence of Pb in Sargassum oligocystum species has been observed to exceed the maximum international guidance level. Given that some of the algae species are cultivated for human consumption, the non-carcinogenic and carcinogenic indices were calculated, shown to be slightly lower than the maxima recommended by the international organizations. Overall, the present results are consistent with literature data suggesting that heavy metal macroalgae biomonitoring may be species-specific. To the best of our knowledge, this study represents the first comprehensive macroalgae biomonitoring study of metal contamination from the coastal waters of Cox’s Bazar and beyond.

Y. Khairi, H. Omer, A. Sulieman, N. Deiab, Maha H. Mokhtar, Fouad A. Abolaban, M. Alkhorayef, D.A. Bradley (2021)Radiation dose homogeneity and critical organs in radiotherapy treatment of prostate cancer, In: Radiation physics and chemistry (Oxford, England : 1993)178 Elsevier Ltd

Present study compares two different 3D radiotherapy techniques: three-dimensional conformal radiotherapy (3D-CRT) and 3D external-beam radiation dose fields from computerized treatment plans, produced for 30 prostate cancer patients. All of the patients were the subject of treatment at the National Cancer Institute in Egypt. Evaluation was made of dose homogeneity within the target volume and the dose to critical organs (organs at risk, OAR). The plans were based on CT scans, all for cases of localized prostate cancer (all stage T2N0M0), with the CT scans transferred to the treatment planning systems. Comparison of the two different 3D radiation techniques was made in terms of isodose distributions and dose-volume histograms. The percentage of the planning target volume receiving 95% (V95) and 107% (V107) of the prescribed dose were obtained. For the 3D-CRT technique, the mean values for these were respectively 90.6% and 5.7% while for the other 3D technique they were 94.9% and 3.8%. In examining the dose received by the OAR, use of the 3D-CRT technique was found to provide the preferred dose distribution, with much greater sparing of the bladder, rectum and head of both femora. For the rectum the mean V70, V75 and D95 values (the latter referring to doses to 95% of the treatment volume) for the 3D-CRT technique were 35.5%, 32.2% and 34% while for the other 3D technique these were 8.4%, 0.2% and 12% respectively. For the bladder, the mean V40 and V65 values obtained using the 3D-CRT technique were 80.8% and 74.9% while for the alternative 3D technique they were 20.4% and 17% respectively. Thus for the particular cohort, the 3D-CRT technique provided superior target coverage and reduction of dose to the OAR. •Dosimetric comparison made of comparison of two different 3D-CRT and 3D techniques for treatment of prostate cancer.•Comparison performed using isodose distributions and dose-volume histograms.•3D planning provides a better target coverage and reduces dose to the OAR.

Ahmed E. Abdel Gawad, Khaled Ali, Hassan Eliwa, M. I. Sayyed, Mayeen Uddin Khandaker, David A. Bradley, Hamid Osman, Basem H. Elesawy, Mohamed Y. Hanfi (2021)Radiological investigation on sediments: A case study of wadi rod elsayalla the southeastern desert of egypt, In: Applied sciences11(24) Mdpi

The presence of heavy radioactive minerals in the studied granitoids from which the Wadi sediments leads to the study of the exposure to emitted gamma rays from the terrestrial radionuclides, such as U-238, Th-232, and K-40. The geological study revealed that the Wadi sediments derived from the surrounding granitoids, such as syenogranite, alkali feldspar granite, and quartz syenite. The mineral analysis confirmed that the granitoids were enriched with radioactive minerals, such as uranothorite as well as monazite, zircon, yttrocolumbite, and allanite. The mean activity of the U-238, Th-232, and K-40 concentrations are 62.2 +/- 20.8, 84.2 +/- 23.3, and 949.4 +/- 172.5 Bq kg(-1), respectively, for the investigated Wadi sediments, exceeding the reported limit of 33, 45 and 412 Bq kg(-1), respectively. Public exposure to emitted gamma radiation is detected by estimating many radiological hazard indices, such as the radium equivalent content (Ra-eq), external and internal hazard indices (H-ex and H-in), annual effective dose (AED), annual gonadal dose equivalent (AGDE), and excess lifetime cancer (ELCR). The obtained results of the radiological hazards parameters showed that public exposure to emitted gamma radiation can induce various dangerous health effects. Thus, the application of the investigated sediments in different building materials and infrastructures fields is not safe. A multivariate statistical analysis (MSA) was applied to detect radionuclide correlations with the radiological hazard parameters estimated in the granite samples.

M. Abuzaid, A. Abdelrazig, A. Sulieman, M. Alkhorayef, E. Babikir, B. Alonazi, D.A. Bradley (2020)Radiation dose to the paediatric undergoing diagnostic coronary angiography and percutaneous intervention procedures, In: Radiation physics and chemistry (Oxford, England : 1993)167 Elsevier Ltd

Successful diagnostic and clinical outcomes in use of interventional cardiac imaging procedures make them strong choices in dealing with cardiovascular disease. Interventional procedures in developing countries are now growing markedly, increasing with the availability of equipment and trained staff. Present study in Sudan has examined pediatric radiation doses during Diagnostic Coronary Angiography (DCA) and Percutaneous Intervention Procedures (PCI), identifying relationships leading to high values, in particular with patient characteristics and exposure parameters. Retrospective data analysis from DCA cases (n = 9) and PCI (n = 48) examined patient-based characteristics, exposure parameters and the Kerma Area Product (KAP). For DCA and PCI, the mean KAP and fluoroscopic time were 4372.4 ± 3190.1 and 3877.6 ± 1249.1 cGy cm2 and 5 ± 4.7 and 5.3 ± 3.6 min respectively, with correlations between KAP and weight and KAP and fluoroscopic time of r = 0.91 and r = 0.71 respectively. The radiation dose for children during DCA and PCI is a critical issue, avoidable radiogenic risk, needing to be mitigated through optimization. •Pediatric radiation dose is a critical issue and should be optimized.•Radiation dose benchmark guideline should be available to achieve ALARA.•Monitoring of radiation dose and awareness improvement among healthcare workers.

Awais Khalid, Pervaiz Ahmad, Abdulrahman Alharthi, Saleh 