Objective: To investigate the individual external dose level of some interventional radiology staffs from 2016 to 2020 in Tianjin City. Methods: All 2068 interventional radiology staffs who were included in the work of the Radiation Monitoring Project from 2016 to 2020 were selected as study subjects in March 2021. The individual dose monitoring results of interventional radiology staffs of different ages, working years, time and medical institutions were analyzed. Results: Among 2068 interventional radiology workers, 1406 (67.99%) were male and 662 (32.01%) were female. The age was 44.6 (39.2, 50.3) years, and the working years was 10.5 (4.3, 14.6) years. The annual effective doses per capita of 40-49 age group and ≥50 age group were higher than that of 30-39 age group (P<0.05) . The annual effective dose per capita of 5-9 working years was higher than that of <5 working years, and the annual effective dose per capita of 10-29 working years was higher than that of 5-9 working years (P<0.05) . The median per capita annual effective dose of the interventional radiology staffs was 0.164 mSv. There were 1976 interventional radiology staffs with an annual effective dose of <0.50 mSv/a (95.6%) . The collective dose distribution ration SR(0.5) was 41.1%. The difference of effective dose per capita in each year was statistically significant (H=19.23, P<0.05) . The per capita annual effective dose of interventional radiology staffs in tertiary medical institutions was higher than that in secondary medical institutions, and the difference was statistically significant (P<0.05) . Conclusion: The personal dose of interventional radiology staffs in Tianjin City is at a low level. It is necessary to emphasize the radiation hazard protection of interventional radiology staffs in tertiary medical institutions, 40-49 years old, ≥50 years old age groups and 5-9, 10-29 working years groups.
Adult ; Female ; Humans ; Male ; Middle Aged ; Occupational Exposure/prevention & control* ; Radiation Dosage ; Radiation Monitoring/methods* ; Radiation Protection ; Radiology, Interventional

PURPOSE: To calculate the effective doses of cone-beam computed tomography (CBCT) using personal computer-based Monte Carlo (PCXMC) software (Radiation and Nuclear Safety Authority, Helsinki, Finland) and to compare the calculated effective doses with those measured using thermoluminescent dosimeters (TLDs) and an anthropomorphic phantom. MATERIALS AND METHODS: An Alphard VEGA CBCT scanner (Asahi Roentgen Ind. Co., Kyoto, Japan) with multiple fields of view (FOVs) was used for this study. The effective doses of the scout and main projections of CBCT using 1 large and 2 medium FOVs with a height >10 cm were calculated using PCXMC and PCXMCRotation software and then were compared with the doses obtained using TLD-100 LiF and an anthropomorphic adult human male phantom. Furthermore, it was described how to determine the reference points on the Y- and Z-axes in PCXMC, the important dose-determining factors in this software. RESULTS: The effective doses at CBCT for 1 large (20.0 cm×17.9 cm) and 2 medium FOVs (15.4 cm×15.4 cm and 10.2 cm×10.2 cm) calculated by the PCXMC software were 181, 300, and 158 µSv, respectively. These values were comparable (16%–18% smaller) to those obtained through TLD measurements in each mode. CONCLUSION: The use of PCXMC software could be an alternative to the TLD measurement method for effective dose estimation in CBCT with large and medium FOVs.
Adult ; Cone-Beam Computed Tomography ; Humans ; Male ; Methods ; Radiation Dosage ; Radiation Protection

In order to overcome the shortcomings of traditional X-ray inspection taking passive protection mode, this paper combines the automatic control technology, puts forward a kind of active protection X-ray equipment. The device of automatic detection of patients receiving X-ray irradiation part, intelligent adjustment in patients and shooting device between automatic tracking radiation protection device height. The device has the advantages of automatic adjustment, anti-radiation device, reduce the height of non-irradiated area X-ray radiation and improve the work efficiency. Testing by the professional organization, the device can decrease more than 90% of X-ray dose for patients with non-irradiated area.
Humans ; Radiation Dosage ; Radiation Protection ; instrumentation ; methods ; X-Rays

Radiation therapy is an important treatment modality for abdominal or pelvic cancer, but there is a common and serious complication such as radiation-induced enteritis. Probiotics is reported to have positive effects against radiation-induced enteropathy. In this study, morphological changes of bowel mucosa were analyzed in rats to presume the effect of probiotics on radiation-induced enteritis and its correlation with radiation dose. A total of 48 adult male Sprague-Dawley rats were randomly assigned to two groups and received a solution containing 1.0x108 colony-forming units of Lactiobacillus acidophilus or water once daily for 10 days. Each of two groups was divided into three subgroups and abdomino-pelvic area of each subgroup was irradiated with 10, 15, and 20 Gy, respectively on the seventh day of feeding the solutions. All rats were sacrificed 3 days after irradiation and the mucosal thickness and villus height of jejunum, ileum and colon were measured. The morphological parameters of the small intestine represented significant differences between two solution groups irradiated 10 or 15 Gy, except for villus height of jejunum in 15 Gy-subgroup (P=0.065). There was no significant morphometric difference between two groups irradiated with 20 Gy of radiation. Probiotics appear to be effective for the morphological shortening of small intestinal mucosa damaged by radiation less than or equal to 15 Gy.
Animals ; Colon/pathology ; Disease Models, Animal ; Enteritis/pathology/prevention & control ; Ileum/pathology ; Intestinal Mucosa/microbiology/*radiation effects ; Intestine, Small ; Jejunum/pathology ; Lactobacillus acidophilus/*metabolism ; Male ; Probiotics/administration & dosage/*pharmacology ; Radiation Injuries, Experimental/*prevention & control/therapy ; Radiation Protection/*methods ; Random Allocation ; Rats ; Rats, Sprague-Dawley

BACKGROUND/AIMS: ERCP using fluoroscopy should be practiced with an adequate radiation protection. However, the awareness of gastrointestinal endoscopists to radiation protection was considered insufficient. In Korea, a country with a rapid increase the number of ERCP procedures, there is no data about radiation protection practices for gastrointestinal endoscopists. The purpose of this study was to investigate current clinical practices and the awareness on radiation protection in ERCP performing physicians in Korea. METHODS: An anonymous questionnaire regarding radiation protection practices was mailed to 100 members of Korean Pancreatobiliary Association who was porforming ERCP. The questionnaire included ERCP volume of each endoscopist, use of protection devices such as apron, thyroid shield, lead glasses and any mobile shield for scattered radiation, and whether they monitored their own radiation exposure dosage. RESULTS: All respondents wore lead aprons during ERCP. While 52.5% of endoscopists answered that they always wear thyroid guards, 26.9% rarely or never wore it. Only 14% wore lead glasses during the procedure and 69% never wore it. The preparation rates of mobile shields or lead curtains were only 14% and 24%, respectively. Only 10% of endoscopists attached an X-ray badge and 66.7% never used it. Moreover, 75% of endoscopists responded that they did not monitor their own exposure dose to radiation during ERCP. CONCLUSIONS: The lack of radiation protection of ERCP endoscopists in Korea was seemed serious. Awareness of radiation hazard should be more concerned and educated in parallel with the preparation of radiation protection equipments.
*Cholangiopancreatography, Endoscopic Retrograde ; Eye Protective Devices ; Female ; Hospitals ; Humans ; Male ; Occupational Exposure/*prevention & control ; Questionnaires ; Radiation Monitoring ; Radiation Protection/*methods ; Thyroid Gland/radiation effects

BACKGROUND/AIMS: The increasing use of diagnostic and therapeutic endoscopic retrograde cholangiopancreatography (ERCP) calls for greater consideration of radiation exposure risk to endoscopists and assistants, and emphasizes the proper system of radiation protection. This study was designed to assess the effect of a newly developed, self-designed, protective lead shield. METHODS: A curtain-shaped protective shield composed of seven movable lead plates was developed, each with the following dimensions: depth, 0.1 cm; width, 15 cm; length, 70 cm. The curtain-shaped protective shield was designed to be located between the patient and the endoscopist. Twenty-nine patients (11 men and 18 women) undergoing ERCP between January 2010 and March 2010 were selected for this study. The dose of radiation exposure was recorded with or without the protective lead shield at the level of the head, chest, and pelvis. The measurement was made at 50 cm and 150 cm from the radiation source. RESULTS: The mean patient age was 64 years. The mean patient height and weight was 161.7+/-6.9 cm and 58.9+/-9.9 kg, respectively. The mean body mass index (BMI) was 22.5+/-3.0 kg/m2. Endoscopists received 1522.2+/-537.0 mR/hr without the protective lead shield. At the same distance, radiation exposure was significantly reduced to 68.8+/-88.0 mR/hr with the protective lead shield (p-value<0.0001). The radiation exposure to endoscopists and assistants was significantly reduced by the use of a protective lead shield (p value<0.0001). The amount of radiation exposure during ERCP was related to the patient's BMI (r=0.749, p=0.001). CONCLUSIONS: This self-designed, protective lead shield is effective in protecting endoscopists and assistants from radiation exposure.
Adult ; Aged ; Body Mass Index ; Cholangiopancreatography, Endoscopic Retrograde/*adverse effects ; Common Bile Duct Diseases/diagnosis/therapy ; Female ; Humans ; Male ; Middle Aged ; Radiation Dosage ; Radiation Injuries/*prevention & control ; *Radiation Monitoring/methods ; Radiation Protection/*methods

Concerns have been raised over x-ray radiation dose associated with repeated computed tomography (CT) scans for tumor surveillance and radiotherapy planning. In this paper, we present a low-dose CT image reconstruction method for improving low-dose CT image quality. The method proposed exploited rich redundancy information from previous normal-dose scan image for optimizing the non-local weights construction in the original non-local means (NLM)-based low-dose image reconstruction. The objective 3D low-dose volume and the previous 3D normal-dose volume were first registered to reduce the anatomic structural dissimilarity between the two datasets, and the optimized non-local weights were constructed based on the registered normal-dose volume. To increase the efficiency of this method, GPU was utilized to accelerate the implementation. The experimental results showed that this method obviously improved the image quality, as compared with the original NLM method, by suppressing the noise-induced artifacts and preserving the edge information.
Algorithms ; Artifacts ; Humans ; Imaging, Three-Dimensional ; methods ; Phantoms, Imaging ; Radiation Dosage ; Radiation Protection ; standards ; Radiographic Image Interpretation, Computer-Assisted ; methods ; standards ; Tomography, X-Ray Computed ; methods

OBJECTIVETo study the impact of different planning target volume (PTV) margin settings on surface and superficial dose distribution and explore the resolution of high superficial dose when the target area is close to the surface during head and neck intensity-modulated radiotherapy (IMRT).

METHODSA typical superficial target volume was designed in an circular neck phantom. Two experimental inverse IMRT plans were conducted with 8MV X ray, and in plan A, the superficial side of PTV margin ranged from 0 to 5 mm, while other side margins were 5 mm; in plan B, an suppositional machine dosimetry data for IMRT optimization was established in which the build-up dose was eliminated, and this machine data was used to optimize the inverse IMRT plan followed by recalculation of the planned dose distribution with the actual clinical machine dosimetry data. The variation of the surface and superficial dose resulting from set-up error and the dose distribution to CTV were compared. The adequate PTV margin was analyzed when the CTV approached the surface.

RESULTSIn plan A, the high dose greater than the prescribed dose was found in the surface and superficial region when the superficial sparing distance was between the surface and PTV d<3 mm, and the 3 mm set-up margin increased this superficial dose remarkably. Reducing the superficial side of PTV margin lowered the high superficial dose effectively and allowed maintenance of the prescribed dose to the CTV. To avoid reduction of the dose to the CTV to below 95% of the prescribed dose, the superficial side of PTV margin should be greater than 1 mm. Plan B effectively lowered the surface doses and maintained the prescribed dose to the CTV.

CONCLUSIONSWith appropriate techniques for optimizing inverse IMRT, more homogeneous superficial dose can be achieved.

Computer Simulation ; Head and Neck Neoplasms ; radiotherapy ; Humans ; Radiation Injuries ; prevention & control ; Radiation Protection ; methods ; Radiotherapy Planning, Computer-Assisted ; methods ; Radiotherapy, Intensity-Modulated ; methods ; standards ; Skin ; radiation effects

OBJECTIVE: To assess effects of off-centering, automatic exposure control, and padding on attenuation values, noise, and radiation dose when using in-plane bismuth-based shields for CT scanning. MATERIALS AND METHODS: A 30 cm anthropomorphic chest phantom was scanned on a 64-multidetector CT, with the center of the phantom aligned to the gantry isocenter. Scanning was repeated after placing a bismuth breast shield on the anterior surface with no gap and with 1, 2, and 6 cm of padding between the shield and the phantom surface. The "shielded" phantom was also scanned with combined modulation and off-centering of the phantom at 2 cm, 4 cm and 6 cm below the gantry isocenter. CT numbers, noise, and surface radiation dose were measured. The data were analyzed using an analysis of variance. RESULTS: The in-plane shield was not associated with any significant increment for the surface dose or CT dose index volume, which was achieved by comparing the radiation dose measured by combined modulation technique to the fixed mAs (p > 0.05). Irrespective of the gap or the surface CT numbers, surface noise increased to a larger extent compared to Hounsfield unit (HU) (0-6 cm, 26-55%) and noise (0-6 cm, 30-40%) in the center. With off-centering, in-plane shielding devices are associated with less dose savings, although dose reduction was still higher than in the absence of shielding (0 cm off-center, 90% dose reduction; 2 cm, 61%) (p < 0.0001). Streak artifacts were noted at 0 cm and 1 cm gaps but not at 2 cm and 6 cm gaps of shielding to the surface distances. CONCLUSION: In-plane shields are associated with greater image noise, artifactually increased attenuation values, and streak artifacts. However, shields reduce radiation dose regardless of the extent of off-centering. Automatic exposure control did not increase radiation dose when using a shield.
Analysis of Variance ; Artifacts ; Phantoms, Imaging ; Radiation Dosage ; Radiation Protection/*methods ; *Tomography, X-Ray Computed

In order to improve the diagnostic quality of X-ray device and to promote the implementation of radiation protection in accordance to the ICRU definition and ICRP classification standards for measuring radiation harm to human body, we have made a number of tests, including the kinetic energy released by ionizing air, the Half-value layer, the output dose coincidence, the High contrast resolution, the Consistency between visual light field and project X-ray field, and the Focus of X-ray tube. We have also analysed the measured data and results. The tests were conducted on the XEB150L-20 made by Shimadzu Co. in the middle of 1990s.
Quality Control ; Radiation Dosage ; Radiation Monitoring ; methods ; Radiation Protection ; methods ; Radiography ; instrumentation ; Radiometry ; methods