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About 70% of all collective doses from medical tests come from computed tomography (CT), the primary public radiation exposure source. Patients received higher doses during contrast-enhanced CT procedures (Angiography) than routine CT procedures. The current research aims to quantify the patients' radiation doses, estimate the cancer risk probability, and establish institutional diagnostic reference level (IDRL) during lower extremity angiography. One hundred eleven patients (61.3% male and 38.7% female) underwent contrast-enhanced CT procedures. A 160-Slice CT scanner was used for image acquisition for all patient populations. IDRL values were quantified based on the 3rd quartile value of the CT dose descriptors. All procedures were carried out at Al-Moaallim Medical City, Khartoum, Sudan. A computer software (CT-Expo, ImPACT) was used to extrapolate the effective dosage per extremity CTA examination was estimated. The mean patient age (years) was 56.1 ± 18 (18–82). The patient's radiation doses was quantified using volume CTDI and dose length product (DLP) to 7.3 ± 2 (2.9–16.8) (mGy) and 3712 ± 126 (279–8374) (mGy.cm), respectively. The average effective doses were 22 mSv (range: 1.7–50) per lower CT angiography for the lower extremity. The proposed IDRL for the VCTA procedure was 3562 mGy cm and 17 mGy for DLP and CTDIvol, respectively. The proposed IDRL is higher than the previously published studies; therefore, patient dose optimization is recommended. • Radiation doses were determined for patients undergoing VCTA procedure. • A 160-Slice CT scanner with iterative reconstruction techniques was used for examining the patients. • The average effective doses were 22 mSv (range: 1.7–50) per VCTA. • The proposed LDRL for the VCTA procedure was 3562 mGy cm and 17 mGy for DLP and CTDIvol, respectively. [ABSTRACT FROM AUTHOR]

Cardiovascular nuclear medicine (NM) imaging examinations expose patients to extremely high absorbed doses of ionizing radiation, which necessitates extensive efforts to reduce the doses without compromising the quality of images. This study aims to assess patients' radiation doses to patients and public exposure in Cardiac rest and stress single photon emission computed tomography (SPECT) scans. The patients' exposure was calculated for 21 patients using the administered activity (AA, MBq). (GE SPECT) was the device used for all patients. AA (MBq) mean and range were 370 for Rest and 1110 for Stress. The average range of the dose rate was 1.59 (0.67–2.34) mR/h for rest and 7.29 (4.2–9.98) mR/h for stress when computed at 30 cm from the patient's chest level after injection. At 100 cm from the patient, the mean dose rate values were 0.37 (0.16–0.73) mR/h for rest and 1.39 (1.01–2.0) mR/h for stress. The overall effective dose is 12.1 mSv per rest and stress SPECT procedure. The mean effective dose for cardiac rest is comparable with previously published studies while the effective dose from cardiac stress is higher than previously published studies. The variation in the effective dose depends on several factors, including the department's clinical indication imaging protocols and radiation safety measures. • The patient's effective dose and dose were quantified during cardiac rest and stress SPECT procedures. • The mean effective dose for cardiac rest is comparable with previously published studies. • The effective dose from cardiac stress is higher than previously published studies. • The current AA activity for rest and stress is lower than the DRL and the previous studies. [ABSTRACT FROM AUTHOR]

Renal diseases and urinary tract disorders are causing a global burden, with an estimated prevalence of around 13%. Contrast-enhanced computed tomography urography (CE-CTU) is a well-known diagnostic technique for urinary system diseases for initial diagnosis and, very often, for follow-up. CE-CTU procedure exposes patients to high doses of ionizing radiation; hence, justification and optimization of doses are necessary to maximize the benefits and minimize the patients' risks. This study aims to evaluate radiation doses to patients during CE-CTU procedures and estimate the subsequent radiogenic risk. The study included twenty-seven patients who underwent CE-CTU examination in two different hospitals (National Ribat Hospital (NRH) and National Security Fource Hospital (NSFH)), where 16-slice CT machines from different vendors are used. The variables and significance were analyzed using SPSS and Scheffe's statistical tool. Data collected included the age of patients (19–70 years), the radiation dose received by patients: dose length product (DLP, mGy.cm) and volume CT dose index (CTDIvol (mGy)), and tube current-time product (mAs). Patients' dose measurements per CE-CTU procedure given as (mean and range) was: DLP 3098 (647–5301) (mGy.cm) and CTDIvol 44.11 (15–136) (mGy). The results revealed statistically significant differences in DLP (mGy.cm), CTDIvol (mGy), and mAs, and this could be attributed to discrepancies in protocols, machines, and operators among the hospitals and within each hospital. Considering gender, the variables (age, tube current-time product (mAs), and CTDIvol) showed no statistically significant differences. The radiogenic risks from the CE-CTU procedure were ≈1 per 400. Comparison between the two hospitals showed that the variables varied significantly between the hospitals studied, but no significant differences were found based on gender. CE-CTU with contrast medium exposes patients to high doses. Therefore, proper dose optimization is crucial. • 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. • The effective and cancer risk are around ten times lower during IVU procedures compared to CTU. [ABSTRACT FROM AUTHOR]

Mammary glands or breasts are radiosensitive organs that makeup 12% of the body's overall radiation sensitivity. According to estimates, Saudi Arabia has a 27.3% overall cancer incidence rate for breast cancer. Recent studies reported that breasts get significant organ equivalent doses during diagnostic procedures with ionizing radiation, even though the breast is not the target organ. The objective of this work is to assess the effective and breast equivalent doses during positron emission tomography (PET)/Computed tomography (CT) imaging examinations. The effective and breast equivalent doses per PET/CT (GE PET/CT 710) examination were quantified using the amount of the injected radiopharmaceutical (MBq) (18F- fluorodeoxyglucose (FDG)), and external doses from CT examinations. The average, standard deviation (SD) and range of examined patients' age (years) and body mass index ((BMI), kg/m2) were 58 ± 11 (39–76) and 30 ± 5 (20.7–43.1), respectively. Constant administered activity (AA, 185 MBq) and tube potential (120 kVp) were used for all patients. The average, SD, and range of the patients effective dose (mSv) from PET/CT (18F- FDG) examination was 8.0 ± 0.93 (7.0–10.0) and 2.075 ± 0.11 (1.91–2.29) in that order. Breast doses are comparable with previous studies during the PET/CT and mammographic examination. Proper justification criteria and dose optimization are essential to lowering excessive exposure while preserving image quality, especially for young females because they have a higher risk of radiation-induced cancer. • Breast doses during PET/CT imaging procedures were evaluated. • Breast absorbed dose depends on CT protocol and administered activity. • The organ equivalent dose ranged from 1.91 to 2.29 mGy per procedure. • Breast doses are comparable with previous studies PET/CT procedures. • Young females have a higher risk of breast cancer due to PET/CT procedure. [ABSTRACT FROM AUTHOR]

Graphite ion chambers and semiconductor diode detectors have been used to make measurements in phantoms but these active devices represent a clear disadvantage when considered for in vivo dosimetry. In such circumstance, dosimeters with atomic number similar to human tissue are needed. Carbon nanotubes have properties that potentially meet the demand, requiring low voltage in active devices and an atomic number similar to adipose tissue. In this study, single-wall carbon nanotubes (SWCNTs) buckypaper has been used to measure the beta particle dose deposited from a strontium-90 source, the medium displaying thermoluminescence at potentially useful sensitivity. As an example, the samples show a clear response for a dose of 2 Gy. This finding suggests that carbon nanotubes can be used as a passive dosimeter specifically for the high levels of radiation exposures used in radiation therapy. Furthermore, the finding points towards further potential applications such as for space radiation measurements, not least because the medium satisfies a demand for light but strong materials of minimal capacitance. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The young are significantly more sensitive to radiation than adults, by up to 3 times, due to their rapidly dividing cells and anticipation of a relatively longer lifespan. Positron emission tomography (PET)/Computed tomography (CT) plays a major role in the diagnosis of many clinical disorders, albeit with patients being subject to enhanced radiogenic risk from ionizing radiation. The aims of present research are to assess the effective doses during pediatric PET/CT examination using 18F-Sodium fluoride (18F-NaF) and 18F- Fluorodeoxy- d -glucose (18F-FDG) radiotracers. A total of 122 pediatric patients were examined, 78% (95 patients) and 22% (27 patients) undergoing 18F-FDG and 18F-NaF studies, respectively. The patients were scanned using two General Electric (GE) Discovery 710 128 slice PET/CT facilities installed in two tertiary hospitals. Patients were categorized into three age groups: ≤5 years, 6 - ≤10 years and 11 - ≤15 years. Per procedure, the mean cumulative effective doses (in mSv) for 18F-FDG group were 12.1, 10.7 and 12.1 for the three respective age groups. Moreover, the mean cumulative effective doses (in mSv) for 18F-NaF group were 6.8, 6.4 and 7.1 for the same three respective age groups. The cumulative effective doses have been found to be comparable with previous studies. • Effective doses evaluated during pediatric PET/CT examination using 18F-NaF and 18F FDG radiotracers. • The PET/CT 18F FDG radiation effective doses have been found to be comparable with previous studies. • The pediatric doses resulted from 18F FDG procedures is 40% higher than the 18F-NaF procedures. • CT contributed up to 80% of patient effective radiation dose during PET/CT procedure. [ABSTRACT FROM AUTHOR]

75 μm thick PTFE tape attracts interest, forming the basis of a potential skin dosimeter capable of utilization in radiotherapeutic external beam applications. The medium is readily available, for instance in the form of ordinary plumber's tape as used herein, typically of 12 mm width mounted on a spool. A60Co (mean energy 1.25 MeV) irradiator has been used to deliver doses in the range 0.1- to 10 Gy, with disrupted molecular bonds inspected via Raman spectrometry. The peak of greatest magnitude, at a wavenumber of ∼734 cm−1, corresponds to the difluoromethylene (CF 2) symmetric stretching mode. Reduction in the peak intensity is seen to occur over the range 0.1- to 5 Gy, covering the values of skin dose typically arising in a single fractionated radiotherapeutic treatment. Results from these preliminary investigations point to a technique offering viability for radiotherapy skin dosimetry, utilizing a soft, low atomic number medium of particularly low-cost, also available in hypoallergenic form. • Molecular disruptions in irradiated PTFE tape investigated for skin dosimetry. • Doses in the range of 0.1- to 10 Gy evaluated. • TOPAS Monte Carlo code simulations carried out. • Raman spectroscopy of 75 μm thick PTFE offers dosimetric utility. [ABSTRACT FROM AUTHOR]

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. • Patients' organs dosimetry in targeted radionuclide therapy were carried out in Kuwait Cancer Control Centre. • A total of 18 patients were undergone theranostic procedures with 177Lu Dotatate. • Organ and total patients doses were calculated using Organ Level INternal Dose Assessment (OLINDA) Software. • Optimization of the PET/CT imaging protocol is recommended to assure that patients received a minimal effective dose. [ABSTRACT FROM AUTHOR]

The main objective of this study is to identify the atmospheric 7Be concentrations in 130 surface air samples collected from three stations located in Riyadh, Haql and Khafji cities in Saudi Arabia between November 2012 and April 2014. Monthly variations as well as seasonal patterns of 7Be were studied using a medium-volume air sampler and a gamma spectroscopy system equipped with a high-purity germanium (HPGe) detector. 7Be exhibited one maximum specific activity in summer and one minimum in winter with average monthly concentrations of 12.4 ± 0.9, 15.4 ± 1.2, and 18.0 ± 1.3 mBq m−3 in Riyadh, Haql and Khafji, respectively. Overall, the average 7Be concentration in the three stations was 12.9 ± 1.0 mBq m−3, whereas the maximum value of 29.5 mBq m−3 was registered in Khafji city in August 2013. Besides 7Be, measurements indicate observations of 40 K, 137Cs, 226Ra radionuclides in surface air samples collected from the three stations. 40 K showed measurable concentrations, whereas the concentrations of 137Cs and 226Ra were only detected in a limited number of samples. • 7Be were studied using a medium-volume air sampler and a gamma spectroscopy system. • The measurements were performed in three locations in Saudi Arabia. • 4 K showed measurable concentrations, whereas the concentrations of 137Cs and 226Ra were below the detection limit. • 7Be and 4 K radionuclides were affected by local atmospheric conditions. [ABSTRACT FROM AUTHOR]

Abstract The monitoring of concentrations of metals in road dust can be used in evaluating vehicular contributions to the environment. Here we compare the efficacy of several analytical techniques for such samples: XRF, SEM/EDX and ICP-MS, providing for both qualitative and absolute quantitative analysis. To-date we have made evaluation of key elemental levels from roadside dust sampled at different locations within the University of Surrey and the Kuwait Research Institute, in so-doing also investigating the influence of engine size (Kuwaiti vehicles tending to be of larger engine capacity than those in the UK) and the influence of climate, maritime and arid in the present case. With a total of 36 street dust samples collected to-date, 18 have now 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 University of Surrey samples, obtained at three different times of the year, SEM/EDX findings range from below the lower limit of detection for Ag, through to 4.7 × 10−6 mg/m2 for Co, up to 3.6 × 10−2 mg/m2 for Fe. Using ICP-MS on sieved University of Surrey road dust samples similarly taken at different times of the year, mean particle dimensions < 45 µm (i.e. respirable dust) have been obtained yielding elevated elemental concentrations in units of mg/kg (ppm), with mean values as follows: Cu (70.4 mg/kg), Zn (288 mg/kg,) Al (3081 mg/kg) and Fe (14,133 mg/kg). These values can be compared against that for Co (3.5 mg/kg) and V (12.3 mg/kg), a primary source of the latter deriving from their use in vehicle tyres production, also for 78.0 mg/kg (Pb). Other toxic metals found in the Guildford and Kuwait samples in different low concentrations were Ti, Cr, and Ba. The concentrations of Pb were found to be low compared to previous analyses, attributable to modern restrictions on Pb in fuel. Au and Ag were also detected, albeit in very low concentrations in the samples from both countries, in particle sizes of the order of 0.5 µm. In summary, present study shows a number of elements presenting at particularly elevated concentrations, a major source being motorpart wear debris. Highlights • A range of predominantly metallic element concentrations in road dust measured. • Comparison has been made between concentrations in the UK and Kuwait. • With ICP-MS and SEM/EDX, Al, Fe, Mn, and Zn levels were found. • Lower Pb levels were found in the UK samples. • At smaller particle sizes concentrations are observed to be much enhanced. [ABSTRACT FROM AUTHOR]

Abstract Over the past several years a great deal of research has focused on the adaptation of carbon nanotubes (CNTs) for a wide range of applications, including as gas detectors, in energy storage, for various photonics purposes, also as radiation sensors. In previous studies by this group, investigating thermoluminescent (TL) properties, the sensitivity of CNTs towards ionising radiations has been observed using beta radiation at dose levels from fractions of a Gy and more. Strain and impurity defects in CNTs give rise to substantial TL yields, the extent to which electron trapping centres exist varying inversely with the quality of CNT, from super-pure to pure to raw. In present study the contribution to TL of beta particle irradiated CNTs has been investigated with respect to changes in the lattice atomic orbitals, pointing to the possibility of a new radiation dosimetry method. The surface-sensitive method, one highly suited to the thin (few tens of µm thick) CNT samples produced in the form of free-standing buckypaper, is based on use of the X-Ray Photoelectron Spectroscopy (XPS) technique, evaluating sp2 to sp3 hybridisation. The CNT samples have been examined subsequent to irradiation using a relatively large activity 90Sr/90Y radionuclide source (E β = 0.546 MeV/2.28 MeV), delivering doses in the range 0.2–6 Gy, in all three qualities sp2 to sp3 hybridisation being observed to increase with dose deposition. Considerable advantage is seen in making use of such thin CNTs in dosimetry, rendering them particularly suitable for beta particle soft tissue dosimetry. Highlights • Various single-wall carbon nanotube buckypaper samples β-dosed from 0.2- to 6 Gy. • XPS measurement made of sp2 to sp3 hybridisation. • Hybridisation with dose shows linearity, sensitivity increasing with impurity. • Study shows clear relationship between deposited dose and enhancement of sp3. [ABSTRACT FROM AUTHOR]

World-wide, on-going intensive research is being seen in adaptation of carbon nanotubes (CNTs) for a wide variety of applications, particular interest herein being in the thermoluminescent (TL) properties of CNTs and their sensitivity towards energetic radiations. Using beta radiation delivering dose levels of a few Gy it has been observed in previous study that strain and impurity defects in CNTs give rise to significant TL yields, providing an initial measure of the extent to which electron trapping centres exist in various qualities of CNT, from super-pure to raw. This in turn points to the possibility that there may be considerable advantage in using such media for radiation dosimetry applications, including for in vivo dosimetry. CNTs also have an effective atomic number similar to that of adipose tissue, making them suitable for soft tissue dosimetry. In present investigations various single-wall carbon nanotubes (SWCNT) samples in the form of buckypaper have been irradiated to doses in the range 35–1.3 Gy, use being made of a 90 Sr beta source, the response of the CNTs buckypaper with dose showing a trend towards linearity. It is shown for present production methodology for buckypaper samples that the raw SWCNT buckypaper offer the greatest sensitivity, detecting doses down to some few tens of mGy. [ABSTRACT FROM AUTHOR]

Occupational radiation exposure can occur due to various human activities, including the use of radiation in medicine. Occupationally exposed personnel surpassing 7.4 millions, and respresent the biggest single group of employees who are exposed to artificial radiation sources at work. This study compares the occupational radiation dose levels for 145 workers in four different hospitals located in the Aseer region in Saudi Arabia. The occupational exposure was quantified using thermoluminescence dosimeters (TLD-100). The levels of annual occupational exposures in targeted hospitals were calculated and compared with the levels of the international atomic energy agency (IAEA) Safety Standards. An average yearly cumulative dose for the two consecutive years. The average, highest and lowest resulted occupational doses under examination in this work is 1.42, 3.9 mSv and 0.72 for workers in various diagnostic radiology procedures. The resulted annual effective dose were within the IAEA approved yearly dose limit for occupational exposure of workers over 18, which is 20 mSv. Staff should be monitored on a regular basis, according to current practice, because their annual exposure may surpass 15% of the annual effective doses. • Annual occupational dose (Hp(10) were evaluated at four diagnostic radiology department. • Staff doses represent approximately 15% of the annual effective dose. • Students and trainees should be monitored on a regular basis, according to current practice. • Occupational exposure is comparable with the most previously published studies. [ABSTRACT FROM AUTHOR]

The positron emitters (18F-Sodium Fluoride (NaF)) and X-rays used in Positron emission tomography (PET) combined with computed tomography (PET/CT) imaging have a high radiation dose, which results in a high patient dose. The present research intends to determine the radiation dose and risks associated with PET/CT- 18F-Sodium fluoride examinations in patients. The 18F–NaF PET/CT was used to investigate the doses of 86 patients. Patient exposure parameters and ImPACT software were used to calculate mean effective doses. The administered activity of 185 MBq (5.0 mCi) per procedure has a mean and range based on the patient's BMI (BMI). The range of patient effective doses per procedure was found to be 4–10 mSv, with a radiation risk of 1 × 10−5 per procedure. Patient doses are determined by the patient's size, scanner type, imaging protocol, and reconstruction method. For further dose reduction, proper justification and radiation dose optimization is required. • Effective doses were estimated for patients undergoing PET/CT procedures. • CT contributed 66.7% to patient cumulative effective doses (mSv) while (18F–NaF, PET) contributed 33.3%. • Patients dose optimization is recommended during PET/CT examinations. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The objective of present study is estimation of the radioactivity held within the urinary bladder and kidneys 3 h post radiopharmaceutical (99mTc-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 99mTc-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 99mTc-MDP bone scans. • 99mTc-MDP radionuclide biokinetics were simulated using MIRD biokinetics model. • Radionuclide activities for Urinary bladder and kidney were calculated. • The experimentally estimated radionuclide activity in the kidney to be greater by some 50%. • 0.9% of the administered radioactivity remained in the urinary bladder and kidneys 3 h. • Low radiation dose to the urinary bladder and kidneys post 99mTc-MDP bone scans. [ABSTRACT FROM AUTHOR]

The study objectives were to simulate a 6 MV flattening filter-free (FFF) photon beam of a TrueBeam Varian LINAC, using the PRIMO code. The depth-dose profiles for various jaw open fields and cross-beam profiles for various depths inside water phantoms were determined using PRIMO simulations and were compared with the EGSnrc simulation results. A 93% match between both codes has generally been obtained, with a systematic variation in agreement between the two models that increases with field size. The closest agreement, to within 94%, was obtained for a 6 × 6 cm2 jaw open field at 5.0 cm and 10.0 cm depths, better at 10- than at 5.0 cm depth. The effects of how scatter is modelled has been shown to result in the differences. • 6 MV flattening filter-free photon beam of a TrueBeam Varian LINAC was simulated. • PRIMO code simulations were compared with the EGSnrc simulation results. • A 93% match being between both codes has generally been obtained. • PRIMO can be successfully used as an alternative code for dosimetric calculations. [ABSTRACT FROM AUTHOR]

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 (CTDI vol (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. • Patients radiation doses were evaluated during vascular CT procedures for various CT modalities. • Effective dose were estimated using computer software. • The wide range of observed patient doses indicates patients to have been receiving avoidable radiation exposure. • The mean risk of carcinogenesis has been estimated to be 1 in 1000 procedures. [ABSTRACT FROM AUTHOR]