Measurement Of Radiation Exposure Research Articles

OR12-2 | In-Practice Measurement of Radiation Exposure and Protection for (assumed) Pregnant Cardiologists Performing Cardiac Catheterization and Electrophysiology Procedures

OR12-2 | In-Practice Measurement of Radiation Exposure and Protection for (assumed) Pregnant Cardiologists Performing Cardiac Catheterization and Electrophysiology Procedures

Radiation exposure in therapeutic endoscopic retrograde cholangiopancreatography with two types of fluoroscopy systems

AbstractFluoroscopy is necessary for endoscopic retrograde cholangiopancreatography (ERCP). Occupational radiation exposure of staff (endoscopists, nurses, or assistants) is inevitable. Fluoroscopes with a tube over‐couch (OC) rather than under‐couch (UC) may have more radiation reflection dosage on the staff's upper body theoretically, where the most vital organs are. In the study, we assessed the radiation exposure on staff by two different types of fluoroscopes in real‐world practice. Using a radiation dosimeter to measure the radiation dosage on endoscopists and assistants in each ERCP procedure under two different fluoroscopic systems (UC vs. OC). Forty‐one ERCP procedures were enrolled. Dosimeters were used NanoDots for the measurement of personal radiation exposure. Those dosimeters were attached to the left forearm and chest of the endoscopist and only the chest of two assistants, the wall of the ERCP room, and the controlling room in every procedure. Nine‐teen ERCPs were performed under the OC unit, and the other 22 ERCPs were UC method. Fluoroscopic time and output of radiation dose showed no significant difference between the two groups. Radiation exposure in endoscopist were 0.0911[0.1041–0.3974] mGy (OC) versus 0.0276 [0.0080–0.2924] mGy (UC), p < .01 for the forearm; and 0.0318 [0.0070–0.2628] mGy (OC) versus 0.0182 [0.0088–0.1628] mGy (UC), p = .04 for the endoscopist's body. There was no difference in radiation exposure from assistants in both groups. For all the ERCP procedures, the measurement of radiation exposure from high to low is endoscopist's hand, endoscopist's body, assistant 1, assistant 2, and ERCP room (p < .01). Radiation detection from ERCP room is slightly higher but close to controlling room (p = .06). For the safety of occupational radiation protection, tube of fluoroscope UC is better than OC for the endoscopists more than assistants. Besides, the assistant 1 took higher radiation exposure than assistant 2 for each ERCP procedure.

Assessment of dosimetric approaches in evaluating radiation exposure for interventional cardiologists in Sri Lanka.

Interventional cardiologists face significant radiation exposure during interventional cardiology procedures. Therefore, this study focuses on assessing radiation exposure among interventional cardiologists during their procedures. Specifically, it aims to determine the effectiveness of both single and double dosimeter methods in estimating annual occupational radiation doses. This research holds pioneering significance as it represents the very first study undertaken in Sri Lanka. Thirteen interventional cardiologists performed 486 interventional cardiology procedures over three months in three different healthcare institutes. Active Hp(10) dosimeters were placed to measure radiation exposure. Effective doses were calculated using single and double dosimetric algorithms. Annual occupational doses were assessed on an operator basis. Statistical analyses were conducted to assess algorithmic differences and dose variations using the Kruskal-Wallis test and linear regression. The highest annual occupational dose for each dosimetric algorithm received as 2.00 ± 0.24 mSv, 2.29 ± 0.48 mSv, 3.35 ± 0.71 mSv, and 2.64 ± 0.42 mSv, respectively, and remained below the recommended safety limit of 20 mSv/year. The Kruskal-Wallis test revealed no significant differences in the effective doses among double dosimetric algorithms, as well as between single and double dosimetric algorithms (p > 0.05). Linear regression showed strong correlations among various algorithms, demonstrating consistency. The findings of this study hold significant effects on interventional cardiology practice in Sri Lanka, enhancing radiation safety and monitoring.

Measurement of X-Ray Radiation Exposure in Thorax Examinations at Radiology Installation of Wajak Husada General Hospital

The Study aims to measure radiation exposure on X-ray aircraft on chest radiography at the Radiology installation at Wajak Husada General Hospital. Measurements were carried out on the X-ray source tube and in the X-ray room environment at Wajak Husada General Hospital. This research aims to determine the value of radiation exposure and whether the examination room is safe for workers and the general public. Data collection in this research was direct observation in the radiology examination room; then, radiation exposure using a survey meter at points around the X-ray room. The highest exposure to X-ray aircraft was in the control panel room, which was 0.19 µSv/h or 0.88 mSv/y and was still below the dose limit value set by the Regional Head of Bapeten Regulation Number 4 of 2020, namely the dose limit value for workers of 20 mSv/ year and the community it is one mSv/year, concluded that the X-ray aircraft and environment are suitable for use and safe to occupy to implement radiology services.

Radiation exposure doses to the surgical team during hip surgery is significantly higher during lateral imaging than posteroanterior imaging: a cadaveric simulation study

BackgroundFluoroscopy is indispensable when determining appropriate and effective interventions in orthopedic surgery. On the other hand, there is growing concern about the health hazards of occupational radiation exposure. The aim of this cadaveric simulation study was to measure radiation exposure doses to the surgical team during hip surgery.MethodsWe reproduced the intraoperative setting of hip surgery using 7 fresh frozen cadavers (5 male, 2 female) to simulate patients and mannequins to simulate the surgeon, scrub nurse, and anesthesiologist. Six real-time dosimeters were mounted at sites corresponding to the optic lens, thyroid gland, chest, gonads, foot, and hand on each mannequin. The radiation exposure dose to each team member was measured during posteroanterior and lateral fluoroscopic imaging.ResultsRadiation exposure doses to the surgeon were significantly higher during 3 min of lateral imaging than during 3 min of posteroanterior imaging at the optic lens (8.1 times higher), thyroid gland (10.3 times), chest (10.8 times), and hand (19.8 times) (p = 0.018, p = 0.018, p = 0.018, and p = 0.018, respectively). During lateral imaging, the radiation doses to the nurse were 0.16, 0.12, 0.09, 0.72, and 0.38 times those to the surgeon at the optic lens, thyroid, chest, gonads, and foot, respectively. The radiation dose to the anesthesiologist was zero at all anatomic sites during posteroanterior imaging and very small during lateral imaging.ConclusionsRadiation exposure dose was significantly higher during lateral imaging up to 19.8 times comparing to the posteroanterior imaging. It is effective to reduce the lateral imaging time for reducing the intraoperative radiation exposure. In addition, appropriate distance from fluoroscopy resulted in very low exposure for nurses and anesthesiologists. Surgeon should pay attention that surgical staff do not get closer than necessary to the irradiation field.

Measurement of Radiation Exposure of Hands and Fingers of Nuclear Medicine Personnel Using Innovative Low-Cost GM Based System

Pocket dosimeters are used commonly in Nuclear Medicine or radiology workers for daily dose measurement or during certain high radiation exposure procedures for short periods of time. These are expensive and have many maintenance costs. It may not be feasible to procure many at a time due to cost restraints. We designed a low cost remote dose monitoring device for measurement of radiation for short periods of time. Measuring device was constructed using micro Geiger Muller Counter. The micro-Geiger Counter with model no SBM21 was connected to high voltage circuit and the output signal was obtained. After this, output signal was sent it to Arduino circuit running custom code ESP8266 and readings was made on the mobile/ laptop application after connecting to Arduino circuit running custom code ESP8266 via internet. Readings were taken for short durations during certain periods. Readings were compared to the standard measuring instrument simultaneously. The tube was connected to their hands for hand exposure with a wire. Readings were recorded in the form of μSv/h or mSv/h. RESULT: Total readings were taken during various occasions while preparing (59) and dispensing (45) radioisotopes. During preparation of radiopharmaceuticals, average readings for 99mTc-Sestamibi[16 SAMPLE] (100mCi to 250mCi), 99mTc-MDP [21SAMPLE] (150-200mCi) and 99mTc-DTPA [22SAMPLES] (10-20mCi) were 1115 μSv/h, 3083 μSv/h and 453 μSv/h respectively. During dispensing of radiopharmaceuticals, average readings of total 15 sample each for 99mTc-Sestamibi (100mCi to 250mCi), 99mTc-MDP (150-200mCi) and 99mTc-DTPA (10-20mCi) were 351μSv/h, 209 μSv/h and 235 μSv/h respectively. It was feasible for the worker to fit the measuring device in their pocket while working. Conclusion: Our pilot study revealed accurate readings >95% of the times for short periods of time. Study designing, standardization of readings with more real time accuracy can make this method more reliable and is a low cost means to monitor short periods of radiation exposure for radiation workers.

Does radiation exposure during pediatric supracondylar humeral fracture surgery change according to the C-arm position? A comparison of two different techniques

IntroductionIn the surgical treatment of supracondylar humeral fractures (SHF), the surgeon has to stand right next to the fluoroscopy device, so it is very important to know how to use it in the most appropriate way to reduce radiation exposure. The aim of this study was to investigate the effect of using C-arm in uniplanar (inverted) and biplanar (standard-horizontal) configurations on (1) the radiation exposure to the surgeon, and (2) surgical time and fluoroscopy exposure time. Material and methodsThis prospective randomised study was conducted on 20 patients who underwent fluoroscopy during closed reduction and percutaneous pinning for a SHF. In the first configuration, the C-arm was inverted and the image intensifier was used as a surgical table. In the second configuration, the C-arm was used biplanar. The operations were performed by 5 surgeons, with each surgeon using each method only twice. During the operation, to find a value closed to direct radiation exposure measurement was made by attaching a dosimeter to the wrist and scatter radiation exposure was measured by attaching a dosimeter to the neck and waist of the surgeons. The operation time and fluoroscopy exposure time were determined. ResultsThe duration of operations performed with the biplanar C-arm position and the fluoroscopy exposure time in operations performed with the uniplanar method were found to be statistically significantly longer (p = 0.001). The measurements on the dosimeter worn on the neck of surgeons were found to be statistically significantly higher while using the uniplanar C-arm configuration (p = 0.001). There was no statistically significant difference between the dosimeter measurements on the wrists and waists of the surgeons and the C-arm configurations (p = 0.820; p = 0.185). ConclusionsAlthough the use of biplanar C-arm has no effect on radiation exposure to the surgeon's wrist, the most important advantages are that the neck area is exposed to less radiation and it shortens the fluoroscopy time so the use of a biplanar C-arm can be recommended. Level of evidenceLevel II

Paper-Based Vertical Flow Immunoassay for the Point-of-Care Multiplex Detection of Radiation Dosimetry Genes

In a nuclear or radiological incident, first responders must quickly and accurately measure radiation exposure among civilians as medical countermeasures are radiation dose-dependent and time-sensitive. Although several approaches have been explored to measure absorbed radiation dose, there is an important need to develop point-of-care (POC) bioassay devices that can be used immediately to triage thousands of individuals potentially exposed to radiation. Here we present a proof-of-concept study showing the use of a paper-based vertical flow immunoassay (VFI) to detect radiation dosimetry genes. Using labeled primers during amplification and a multiplex membrane, our results showed that the nucleic acid VFI can simultaneously detect two biodosimetry genes, CDKN1A and DDB2, as well as one housekeeping gene MRPS5. The assay demonstrated good linearity and precision with an inter- and intra-assay coefficient of variance <20% and <10%, respectively. Moreover, the assay showed its ability to discriminate non-irradiated controls (0 Gy) from irradiated samples (1 + 2 Gy) with an overall sensitivity of 62.5% and specificity of 100% (AUC = 0.8672, 95% CI: 0.723–1.000; p = 0.004). Interestingly, the gene combination also showed a dose-dependent response for 0, 1, and 2 Gy, similar to data obtained by real-time PCR benchmark. These preliminary results suggest that a VFI platform can be used to detect simultaneously multiple genes that can be then quantified, thus offering a new approach for a POC biodosimetry assay that could be rapidly deployed on-site to test a large population and help triage and medical management after radiological event.

Patients’ Radiation Exposure During Endovascular Abdominal Aortic Aneurysm Repair

To investigate associations between patient characteristics, intraprocedural complexity factors, and radiation exposure to patients during endovascular abdominal aortic aneurysm repair (EVAR). Elective standard EVAR procedures between January 2015 and December 2020 were retrospectively analyzed. Patient characteristics and intraprocedural data (i.e., type of device, endograft configuration, additional procedures, and contralateral gate cannulation time [CGCT]) were collected. Dose area product (DAP) and fluoroscopy time were considered as measurements of radiation exposure. Furthermore, effective dose (ED) and doses to internal organs were calculated using PCXMC 2.0 software. Descriptive statistics, univariable, and multivariable linear regression were applied to investigate predictors of increased radiation exposure. The 99 patients were mostly male (90.9%) with a mean age of 74±7years. EVAR indications were most frequently abdominal aortic aneurysm (93.9%), penetrating aortic ulceration (2.0%), focal dissection (2.0%), or subacute rupture of infrarenal abdominal aortic aneurysm (2.0%). Median fluoroscopy time was 19.6minutes (interquartile range [IQR], 14.1-29.4) and median DAP was 86,311 mGycm2 (IQR, 60,160-130,385). Median ED was 23.2 mSv (IQR, 17.0-34.8) for 93 patients (93.9%). DAP and ED were positively correlated with body mass index (BMI) and CGCT. Kidneys, small intestine, active bone marrow, colon, and stomach were the organs that received the highest equivalent doses during EVAR. Higher DAP and ED values were observed using the Excluder endograft, other bi- and tri-modular endografts, and EVAR with ≥2 additional procedures. Multivariable linear regression analysis revealed that BMI, ≥2 additional procedures during EVAR, and CGCT were independent positive predictors of DAP and ED levels after accounting for endograft type. Patient-related and procedure-related factors such as BMI, ≥2 additional procedures during EVAR, and CGCT resulted predictors of radiation exposure for patients undergoing EVAR, as quantified by higher DAP and ED levels. The main intraprocedural factor that increased radiation exposure was CGCT. These data can be of importance for better managing radiation exposure during EVAR.

Occupational radiation exposure to the lens of the eyes and its protection during endoscopic retrograde cholangiopancreatography

This study aimed to examine occupational radiation exposure to the lens of the eyes during endoscopic retrograde cholangiopancreatography (ERCP). In this multicenter, prospective, observational cohort study, we collected data regarding occupational radiation exposure to the lens of the eyes during ERCP. We measured radiation exposure of patients and examined its correlation with occupational exposure. In dosimetrically-measured ERCPs (n = 631), the median air kerma at the patient entrance reference point, air kerma-area product, and fluoroscopy time were 49.6 mGy, 13.5 Gycm2, and 10.9 min, respectively. The median estimated annual radiation dose to the lens of the eyes was 3.7, 2.2, and 2.4 mSv for operators, assistants, and nurses, respectively. Glass badge over lead aprons and eye dosimeter results were similar in operators but differed in assistants and nurses. A strong correlation was shown between eye dosimeter measurements and patients' radiation exposure. The shielding rates of the lead glasses were 44.6%, 66.3%, and 51.7% for operators, assistants, and nurses, respectively. This study revealed the actual occupational exposure dose for the lens of the eyes during ERCP and the efficacy of lead glass. Values of radiation exposure to patients can help estimate exposure to the lens of the eyes of medical staff.

179 Measuring Real Time Radiation Exposure to Spine-Focused Neurosurgeons

INTRODUCTION: C-arm fluoroscopy and O-arm navigation are vital tools in modern spine surgeries, but their repeated usage can endanger spine surgeons. While a surgeon’s chest and abdomen are protected by lead aprons, the eyes and extremities generally receive less protection. METHODS: This prospective cohort study includes 65 consecutive spine surgeries performed by a single spine-focused neurosurgeon over a 9-month period. Radiation exposure to the primary surgeon was measured through dosimeters worn over the lead apron, under the lead apron, on surgical loupes, and as a ring on the dominant hand. Differences were assessed with rigorous statistical testing and radiation exposure per surgical case was extrapolated. RESULTS: During the study, the measured radiation exposure over the apron, 176 mrem, was significantly greater than that under the apron, 8 mrem (p = .0020), demonstrating shielding’s protective effect. The surgeon’s dominant hand was exposed to 329 mrem while the eyes were exposed to 152.5 mrem of radiation. Compared to the surgeon’s protected abdominal area, the hands (p = .0002) and eyes (p=.0002) received significantly greater exposure. Calculated exposure per case was 2.8 mrem for the eyes and 5.1 mrem for the hands. It was determined that a spine-focused neurosurgeon operating 400 cases annually will incur a radiation exposure of 60,750 mrem to the hands and 33,900 mrem to the eyes over a 30-year career. CONCLUSIONS: Our study found that spine surgeons encounter significantly more radiation exposure to the eyes and the extremities compared to protected body regions. Lifetime exposure exceeds the annual limits set by the International Commission on Radiological Protection for the extremities (50,000 mrem/yr) and the eyes (15,000 mrem/yr), calling for increased awareness about the dangerous levels of radiation exposure that a spine surgeon incurs over one’s career.

Radiation exposure to staff during fluoroscopic endoscopic procedures.

Fluoroscopically guided procedures utilize ionizing radiation to assist in the diagnosis and treatment of the patient. The use of ionizing radiation is not without risk to the operator and other staff members present during endoscopic procedures. This study simulates radiation exposure during endoscopic retrograde cholangiopancreatography procedures under different shielded conditions and provides practical radiation safety recommendations, through easy-to-use visual guides. We obtained radiation exposure measurements at varying locations with different shielding setups surrounding a mobile C-arm fluoroscopic unit while imaging a patient equivalent phantom at different heights. Heat maps were generated for the various conditions to provide visual guides for radiation protection. Different heat maps detailing various shielding methods have been generated to assist in determining the dose rate at varying locations surrounding the patient. The use of appropriate radiation protection could decrease the staff dose by up to 98%. Although minor per procedure, the magnitude of radiation exposure will accumulate over the staff's working life. As such, it is recommended that precautions be taken during fluoroscopically guided endoscopy procedures to ensure radiation is kept as low as reasonably achievable.

Body Surface Radiation Exposure in Interventional Echocardiographers During Structural Heart Disease Procedures

BackgroundThe distribution of radiation exposure on the body surface of interventional echocardiographers during structural heart disease (SHD) procedures is unclear. ObjectivesThis study estimated and visualized radiation exposure on the body surface of interventional echocardiographers performing transesophageal echocardiography by computer simulations and real-life measurements of radiation exposure during SHD procedures. MethodsA Monte Carlo simulation was performed to clarify the absorbed dose distribution of radiation on the body surface of interventional echocardiographers. The real-life radiation exposure was measured during 79 consecutive procedures (44 transcatheter edge-to-edge repairs of the mitral valve and 35 transcatheter aortic valve replacements [TAVRs]). ResultsThe simulation demonstrated high-dose exposure areas (>20 μGy/h) in the right half of the body, especially the waist and lower body, in all fluoroscopic directions caused by scattered radiation from the bottom edge of the patient bed. High-dose exposure occurred when obtaining posterior-anterior and cusp-overlap views. The real-life exposure measurements were consistent with the simulation estimates: interventional echocardiographers were more exposed to radiation at their waist in transcatheter edge-to-edge repair than in TAVR procedures (median 0.334 μSv/mGy vs 0.053 μSv/mGy; P < 0.001) and in TAVR with self-expanding valves than in those with balloon-expandable valves (median 0.067 μSv/mGy vs 0.039 μSv/mGy; P < 0.01) when the posterior-anterior or the right anterior oblique angle fluoroscopic directions were used. ConclusionsDuring SHD procedures, the right waist and lower body of interventional echocardiographers were exposed to high radiation doses. Exposure dose varied between different C-arm projections. Interventional echocardiographers, especially young women, should be educated regarding radiation exposure during these procedures. (The development of radiation protection shield for catheter-based treatment of structural heart disease [for echocardiologists and anesthesiologists]; UMIN000046478)

A Prospective Cohort Study of Radiation Exposure to a Spine Surgeon's Exposed Body Parts During Utilization of Intraoperative Radiation-based Imaging.

Prospective cohort study. C-arm fluoroscopy and O-arm navigation are vital tools in modern spine surgeries, but their repeated usage can endanger spine surgeons. Although a surgeon's chest and abdomen are protected by lead aprons, the eyes and extremities generally receive less protection. In this study, we compare differences in intraoperative radiation exposure across the protected and unprotected regions of a surgeon's body. Sixty-five consecutive spine surgeries were performed by a single spine-focused neurosurgeon over 9 months. Radiation exposure to the primary surgeon was measured through dosimeters worn over the lead apron, under the lead apron, on surgical loupes, and as a ring on the dominant hand. Differences were assessed with rigorous statistical testing and radiation exposure per surgical case was extrapolated. During the study, the measured radiation exposure over the apron, 176 mrem, was significantly greater than that under the apron, 8 mrem (P = 0.0020), demonstrating a shielding protective effect. The surgeon's dominant hand was exposed to 329 mrem whereas the eyes were exposed to 152.5 mrem of radiation. Compared with the surgeon's protected abdominal area, the hands (P = 0.0002) and eyes (P = 0.0002) received significantly greater exposure. Calculated exposure per case was 2.8 mrem for the eyes and 5.1 mrem for the hands. It was determined that a spine-focused neurosurgeon operating 400 cases annually will incur a radiation exposure of 60,750 mrem to the hands and 33,900 mrem to the eyes over a 30-year career. Our study found that spine surgeons encounter significantly more radiation exposure to the eyes and the extremities compared with protected body regions. Lifetime exposure exceeds the annual limits set by the International Commission on Radiologic Protection for the extremities (50,000 mrem/y) and the eyes (15,000 mrem/y), calling for increased awareness about the dangerous levels of radiation exposure that a spine surgeon incurs over one's career.

COMPARISON OF THE EFFECTIVENESS OF RADIATION SHIELD WALL BETWEEN LEAD-LAYERS AND PLASTERING BRICK-LAYERS

The rate of exposure to X-ray radiation on the radiation shielding wall at the Laboratory 3 of Radiology Study Program Purwokerto Diploma Three Program has been analyzed, to find out the difference in the effectiveness of the radiation shielding wall between a 10 cm thick Lead (2 mm) coated partition and a 28 cm thick stucco brick wall. Measurements were made using a radiation source, namely a mobile unit X-ray machine with a Fluke survey meter radiation measuring instrument. Measurement of the rate of exposure to X-ray radiation is carried out by adjusting the distance of the radiation source with the radiation shield wall from 100 cm, 150 cm and 200 cm and taken from 5 measurement points that represent the radiation shield wall. The measurement results show that measurement point C produces the highest radiation exposure rate and measurement point A produces the lowest radiation exposure rate for Do and D. There is a radiation exposure rate of more than 1 μSv/Hr after passing through a 10 cm thick Lead-coated partition wall (2 mm) at a distance of 100 cm to 150 cm. Radiation shielding walls of walls covered with stucco bricks with a thickness of 28 cm were more effective than partitions covered with lead (2 mm) with a thickness of 10 cm. It is necessary to pay attention to aspects of radiation protection, the use of a mobile unit X-ray machine in placing the X-ray tube in the direction of the X-ray tube and, the radiation source distance of at least 2 meters from the lead-coated partition radiation wall.

Risk of Radiation Exposure to Emergency Department Personnel From Portable Radiographs

BackgroundThere are concerns that emergency health care workers are exposed to ionizing radiation as the result of frequent portable radiographs obtained in the emergency department (ED) during active patient care. ObjectiveOur aim was to investigate whether ED staff are exposed to significant radiation due to scatter from portable radiography at a busy trauma center and whether exposure was related to factors such as location or distance. MethodsThis was a prospective cohort study performed during 3 consecutive months in the ED at a large, academic trauma center. Volunteer attendings, nurses, and resident physicians were asked to wear dosimeter badges during their shifts throughout the study period. Twelve stationary dosimeters were placed in selected locations in the ED, particularly in the resuscitation rooms, where most of the portable radiographs were obtained. ResultsDuring the 3-month study period, 1464 portable radiographs were obtained in the resuscitation rooms in the ED, mostly chest and pelvic radiographs. Analysis from stationary dosimeters placed in the ED showed a median of 0.18 mSv (95% CI 0.16–0.22 mSv) for the main resuscitation room and 0 mSv for other critical care patient rooms. Analysis of dosimeters worn by staff showed no measurable radiation exposure (0.00 mSv). ConclusionsThe level of radiation exposure to ED staff found in this study was well below the recommended allowable occupational exposure of 50 mSv/y. Radiation exposure is not a significant occupational hazard in a busy ED level I trauma center. Existing precautions should adequately protect staff from occupational exposure, and use of further protective gear, or the need for individual monitoring using dosimeters, appears unwarranted.

Determination of a reliable assessment for occupational eye lens dose in nuclear medicine.

The most recent statement published by the International Commission on Radiological Protection describes a reduction in the maximum allowable occupational eye lens dose from 150 to 20 mSv/year (averaged over 5‐year periods). Exposing the eye lens to radiation is a concern for nuclear medicine staff who handle radionuclide tracers with various levels of photon energy. This study aimed to define the optimal dosimeter and means of measuring the amount of exposure to which the eye lens is exposed during a routine nuclear medicine practice. A RANDO human phantom attached to Glass Badge and Luminess Badge for body or neck, DOSIRIS and VISION for eyes, and nanoDot for body, neck, and eyes was exposed to 99mTc, 123I, and 18F radionuclides. Sealed syringe sources of each radionuclide were positioned 30 cm from the abdomen of the phantom. Estimated exposure based on measurement conditions (i.e., air kerma rate constants, conversion coefficient, distance, activity, and exposure time) was compared measured dose equivalent of each dosimeter. Differences in body, neck, and eye lens dosimeters were statistically analyzed. The 10‐mm dose equivalent significantly differed between the Glass Badge and Luminess Badge for the neck, but these were almost equivalent at the body. The 0.07‐mm dose equivalent for the nanoDot dosimeters was greatly overestimated compared to the estimated exposure of 99mTc and 123I radionuclides. Measured dose equivalents of exposure significantly differed between the body and eye lens dosimeters with respect to 18F. Although accurately measuring radiation exposure to the eye lenses of nuclear medicine staff is conventionally monitored using dosimeters worn on the chest or abdomen, eye lens dosimeters that provide a 3‐mm dose equivalent near the eye would be a more reliable means of assessing radiation doses in the mixed radiation environment of nuclear medicine.

In vitro measurements of radiation exposure with different modalities (computed tomography, cone beam computed tomography) for imaging the petrous bone with a pediatric anthropomorphic phantom

BackgroundVarious imaging modalities, such as multi-detector computed tomography (CT) and cone beam CT are commonly used in infants for the diagnosis of hearing loss and surgical planning of implantation hearing aid devices, with differing results.ObjectiveWe compared three different imaging modalities available in our institution, including a high-class CT scanner, a mid-class CT scanner and an angiography system with a cone beam CT option, for image quality and radiation exposure in a phantom study.Materials and methodsWhile scanning an anthropomorphic phantom imitating a 1-year-old child with vendor-provided routine protocols, organ doses, surface doses and effective doses were determined for these three modalities with thermoluminescent dosimeters. The image quality was evaluated using the signal difference to noise ratio (SDNR) and the spatial resolution of a line-pair insert in the phantom head. The dose efficiency, defined as the ratio of SDNR and effective dose, was also compared.ResultsThe organ and surface doses were lowest with the high-class CT protocol, but the image quality was the worst. Image quality was best with the cone beam CT protocol, which, however, had the highest radiation exposure in this study, whereas the mid-class CT was in between.ConclusionBased on our results, high-end CT should be used for surgical planning because it has the lowest dose, while the image quality is still sufficient for this purpose. However, if highest image quality is needed and required, e.g., by ENT surgeons, the other modalities should be considered.

Modeling, simulation and measurement of radiation exposure using electronic personal dosimeters on realistic and ICRU phantoms

Abstract Exposure studies with voxel phantoms were carried out to understand the new personal dose measurand Hp(10) measured by personal dosimeters under realistic wearing conditions. Two simulated realistic voxel phantoms and the dosimeter assembly are described in a first step. Conditions such as photon fluence, radiation field geometry, and photon energy for simulating the external photon fields at the realistic model are specified. Person-related effective doses are calculated to evaluate the personal dose. The relation between measured deep personal dose and effective dose is demonstrated and discussed by means of the simulated response function of the dosimeters at realistic phantoms.

THE MEASUREMENT OF ENVIRONMENTAL RADIATION EXPOSURE AROUND THE LINAC RADIOTHERAPY BUNKER

Radiotherapy is cancer therapy using radiation. One of the tools used for radiotherapy is the Linac. Using Linac also can have a detrimental effect on radiation workers, patients, and the public. The reaction can cause activation around the room to become radioactive. Therefore, radiation protection is needed. This research aimed to measure environmental radiation exposure as a radiation protection effort around the Linac bunker. This research uses a quantitative method by collecting data directly on the area around the Linac bunker, with a distance of ± 30 cm from the bunker wall, using the STEP OD-02 Detector. The average Linac operation is 2000 hours/year, while the safe dose limit used is 1/2 dose Limit from Nuclear Power Monitoring Agency. Based on measurements of environmental radiation exposure, there are eight areas classified as safe and four other regions experiencing radiation leakage, including Doors with a radiation exposure difference of 0.078 Sv/hour; West Field (0.074 Sv/hour); TPS Room (0.302 Sv/hour); and Meeting Rooms (0.199 Sv/hour), but still within the safe limit of radiation dose. The environmental radiation exposure around the Linac Radiotherapy bunker is safe.