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Occupational exposure to ionizing radiation of medical personnel is very common at radiology and nuclear medicine departments. Strict regulations and guidelines for the exposure of staff working in such departments were regulated by international authorities such as the International Atomic Energy Agency (IAEA), and the International Commission on Radiological Protection (ICRP) as well as national protocols. In order to reduce stochastic effects, for example, radiation induced carcinogenesis, the exposure of staff working at nuclear medicine department should be maintained at levels lower than 20 mSv per year or 100 mSv in five years. The objective of this study is to measure staff radiation dose at four radiology departments in the south region of the Kingdom of Saudi Arabia. Exposures received by a total of 106 staff working at the radiology department were monitored for two consecutive years using calibrated Thermoluminecnt dosimeters (LiF:Mg:Ti (TLD-100). Exposure was then quantified in terms of deep dose: Hp (10). The TLD signal was obtained using an automatic TLD reader (Harshaw 6600). The overall annual dose for staff was 1.4 ± 0.37 (0.67–8.74). The study revealed that the annual radiation exposure in the four-radiology department is below the annual dose limits. However, staff doses could be reduced if proper radiation protection are followed. • Staff annual radiation dose were assessed for radiology technologists for two consecutive years. • Occupational doses were quantified with LiF: Mg, Ti (TLD-100). • 90% of monitored staff received an annual occupational dose below 2.0 mSv. • Radiology technologists are well protected against occupational exposure. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Computed tomography angiography (CTA), a noninvasive imaging procedure, is frequently used for the diagnosis of blood vessel diseases. Pediatric patients are more sensitive to radiation than adults due to their rapidly dividing cells and long life expectancy. Thus, evaluation of pediatric exposure is crucial to ensure that the procedure is justified and the practice is optimized. The objectives of this study were to evaluate pediatric patients' exposure and imaging protocols for different CTA procedures and to estimate the cancer risk incidence. A total of 147 pediatric CTA procedures were performed at King Fahad Medical City using three CT machines (Philips Brilliance CT- 64-slice scanner, Siemens Somatom Definition Flash dual source 128 CT slice scanner and GE 750 HD DISCOVERY dual energy 64 CT slice scanner). The image protocol and patient safety measures were evaluated according to American College of Radiology (ACR) criteria. The Ethics and Research Committee approved the study and informed consent was obtained from children's parents. The mean, standard deviation (sd) and range of patients weight (kg) was 8.1 ± 13.2 (3.5–58.7). The mean, sd, median and range of patient dose (mGy.cm) for circle of willis, carotid arteries, thoracic and abdominal aorta, heart and vessels, renal artery, pulmonary artery, abdominal aorta, thoracic aorta, upper lim and lower limb were 992 ± 798, 759.0 (204–2829), 285 ± 157, 660.0 (56.7–652), 500 ± 457, 210.1 (112–1387), 472 ± 317, 411.4, (175–3909) and 350 ± 346, 589.7 (284–1431), respectively. Pediatric average radiation cancer risk incidence was 36 × 10−4. Patients' doses showed wide variation among the three CT machines and even for the same machine and the same clinical investigation. The dose per procedure is higher compared to previous studies, suggesting that the dose is not yet optimized. Protection of radiosensitive organs is highly recommended for pediatric patients. • Pediatric Radiation dose was measured during 10 CTA procedures. • CTA imaging protocol was evaluated against ACR protocol. • Pediatric patients exposed at different exposure parameters with fixed voltage. • The cancer risk is higher compared to other imaging procedures. • Patient doses per procedure is weight dependent. [ABSTRACT FROM AUTHOR]

The advanced image sensors installed on now-ubiquitous smartphones can be used to detect ionising radiation in addition to visible light. Radiation incidents on a smartphone camera's Complementary Metal Oxide Semiconductor (CMOS) sensor creates a signal which can be isolated from a visible light signal to turn the smartphone into a radiation detector. This work aims to report a detailed investigation of a well-reviewed smartphone application for radiation dosimetry that is available for popular smartphone devices under a calibration protocol that is typically used for the commercial calibration of radiation detectors. The iPhone 6s smartphone, which has a CMOS camera sensor, was used in this study. Black tape was utilized to block visible light. The Radioactivity counter app developed by Rolf-Dieter Klein and available on Apple's App Store was installed on the device and tested using a calibrated radioactive source, calibration concrete pads with a range of known concentrations of radioactive elements, and in direct sunlight. The smartphone CMOS sensor is sensitive to radiation doses as low as 10 µGy/h, with a linear dose response and an angular dependence. The RadioactivityCounter app is limited in that it requires 4–10 min to offer a stable measurement. The precision of the measurement is also affected by heat and a smartphone's battery level. Although the smartphone is not as accurate as a conventional detector, it is useful enough to detect radiation before the radiation reaches hazardous levels. It can also be used for personal dose assessments and as an alarm for the presence of high radiation levels. [ABSTRACT FROM AUTHOR]

Image-guided radiation therapy (IGRT) adds an additional imaging radiation dose to existing levels of therapeutic radiation. The extra radiation dose received by organs from multiple conae beam computed tomography (CBCT) scans can increase the probability of the secondary cancer risk. In this study, an effort has been made to assess CBCT dose and image quality for standard pre-sets defined for different organs namely, the chest, pelvis, brain, head and neck, and abdomen. The second goal was to investigate whether the radiation dose could be reduced while still achieving high image quality. Image quality was evaluated on the CatPhan Model 503 (Phantom Lab, NY), while organ kV- CBCT doses were evaluated using an Unfors device (Fluke Biomedical) to provide representative measurements for clinical settings. Nominal CBCT projections with reduced exposure times were reconstructed in 3D using the Unfiltered and Filtered-back Projection algorithms. Patient organ dose (mGy) per procedure for brain, chest, pelvis, abdomen, and head and neck were 7.9, 35.3, 28.1, 58.3, and 0.77, respectively. The experimental analysis suggests that adequate image quality could be obtained while decreasing the number of radiographic projections. Reducing the number of the radiographic projections will reduce the scan time and therefore the imaging dose. The proposed method provides an opportunity to reduce the organ doses comparatively lower than the standard CT doses for head and body protocols. The study provides a framework for delivering low radiation doses to critical organs with no risk of long-term exposure. • This study has successfully quantified CBCT doses for some critical organs. • Image quality and radiation dose were evaluated during CBCT. • Adequate image quality could be obtained while decreasing the number of radiographic projections. • The study provides a framework for delivering low radiation doses to critical organs with no risk of long-term exposure. [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]

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]