• Journal of Radiation Protection and Research
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• v.41 no.4
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• pp.333-338
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• 2016

Background: In case of radiation emergencies, internal exposure monitoring for the members of public will be required to confirm internal contamination of each individual. In-vivo monitoring technique using portable gamma spectrometer can be easily applied for internal exposure monitoring in the vicinity of the on-site area. Materials and Methods: In this study, minimum detectable doses (MDDs) for $^{134}Cs$, $^{137}Cs$, and $^{131}I$ were calculated adjusting minimum detectable activities (MDAs) from 50 to 1,000 Bq to find out the optimal in-vivo counting condition. DCAL software was used to derive retention fraction of Cs and I isotopes in the whole body and thyroid, respectively. A minimum detect-able level was determined to set committed effective dose of 0.1 mSv for emergency response. Results and Discussion: We found that MDDs at each MDA increased along with the elapsed time. 1,000 Bq for $^{134}Cs$ and $^{137}Cs$, and 100 Bq for $^{131}I$ were suggested as optimal MDAs to provide in-vivo monitoring service in case of radiation emergencies. Conclusion: In-vivo monitoring program for emergency response should be designed to achieve the optimal MDA suggested from the present work. We expect that a reduction of counting time compared with routine monitoring program can achieve the high throughput system in case of radiation emergencies.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2405-2425
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• 2014

Radiation exposure leads to several pathophysiological conditions, including oxidative damage, inflammation and fibrosis, thereby affecting the survival of organisms. This review explores the radiation countermeasure properties of fourteen (14) plant extracts or plant-derived compounds against these cellular manifestations. It was aimed at evaluating the possible role of plants or its constituents in radiation countermeasure strategy. All the 14 plant extracts or compounds derived from it and considered in this review have shown some radioprotection in different in vivo, ex-vivo and or in vitro models of radiological injury. However, few have demonstrated advantages over the others. C. majus possessing antioxidant, anti-inflammatory and immunomodulatory effects appears to be promising in radioprotection. Its crude extracts as well as various alkaloids and flavonoids derived from it, have shown to enhance survival rate in irradiated mice. Similarly, curcumin with its antioxidant and the ability to ameliorate late effect of radiation exposure, combined with improvement in survival in experimental animal following irradiation, makes it another probable candidate against radiological injury. Furthermore, the extracts of P. hexandrum and P. kurroa in combine treatment regime, M. piperita, E. officinalis, A. sinensis, nutmeg, genistein and ginsan warrants further studies on their radioprotective potentials. However, one that has received a lot of attention is the dietary flaxseed. The scavenging ability against radiation-induced free radicals, prevention of radiation-induced lipid peroxidation, reduction in radiation cachexia, level of inflammatory cytokines and fibrosis, are some of the remarkable characteristics of flaxseed in animal models of radiation injury. While countering the harmful effects of radiation exposure, it has shown its ability to enhance survival rate in experimental animals. Further, flaxseed has been tested and found to be equally effective when administered before or after irradiation, and against low doses (${\leq}5Gy$) to the whole body or high doses (12-13.5 Gy) to the whole thorax. This is particularly relevant since apart from the possibility of using it in pre-conditioning regime in radiotherapy, it could also be used during nuclear plant leakage/accidents and radiological terrorism, which are not pre-determined scenarios. However, considering the infancy of the field of plant-based radioprotectors, all the above-mentioned plant extracts/plant-derived compounds deserves further stringent study in different models of radiation injury.

• Radiation Oncology Journal
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• v.29 no.4
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• pp.277-282
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• 2011

Purpose: This study was performed to evaluate the change in the lumpectomy cavity volumes before and after whole breast radiation therapy (WBRT) and to identify factors associated with the change of volume. Materials and Methods: From September 2009 to April 2010, the computed tomography (CT) simulation data from 70 patients obtained before and after WBRT was evaluated. The lumpectomy cavity volumes were contoured based on surgical clips, seroma, and postoperative changes. Significant differences in the data from pre-WBRT CT and post-WBRT CT were assessed. Multiple variables were examined for correlation with volume reduction in the lumpectomy cavity. Results: The mean and median volume reduction in the lumpectomy cavity after WBRT were 17.6 $cm^3$ and 16.1 $cm^3$, respectively with the statistical significance (p < 0.001). The volume reduction in the lumpectomy cavity was inversely correlated with time from surgery to radiation therapy (R = 0.390). The presence of seroma was significantly associated with a volumetric change in the lumpectomy cavity after WBRT (p = 0.011). Conclusion: The volume of lumpectomy cavity reduced significantly after WBRT. As the time from surgery to the start ot WBRT increased, the volume reduction in the lumpectomy cavity during WBRT decreased. A strong correlation was observed between the presence of seroma and the reduced volume. To ensure appropriate coverage and to limit normal tissue exposure during boost irradiation in patients who has seroma at the time of starting WBRT, repeating CT simulation at boost planning is suggested.

• Journal of radiological science and technology
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• v.42 no.6
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• pp.455-460
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• 2019

This study compared the radiation transmission and image quality of polymethylmethacrylate (PMMA), polycarbonate (PC), and carbon, which are common components of the compression plates currently used during breast imaging. In addition to measuring the transmitted dose and the intensity without the use of a compression paddle, the four different compression paddles were evaluated according to the material and thickness of each paddle. Radiation transmittance, maximum intensity, and plot profile type w ere all evaluated for each material, and for each factor evaluated the follow ing order w as noted, from best to w orst: carbon 4 mm, PMMA 3 mm, PMMA 4 mm, and PC 4 mm. It is necessary to study a variety of materials and thicknesses in order to find the optimal combination of material and thickness, because not only does the material have a large influence in reducing the radiation exposure during mammography, but the thickness of the compression plate also has a great influence.

• Journal of the Korean Society of Radiology
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• v.9 no.5
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• pp.279-285
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• 2015

The eye of human is a radiation sensitive organ and this organ should be shielded from radiation exposure during brain CT procedures. In the brain CT procedures, bismuth protector using to reduce the radiation exposure dose for eye. But protecting the bismuth always accompanies problem of the image quality reduction including artifact. This study aim is the eye radiation exposure dose and image quality evaluation of the new tube current modulation such as new organ based-tube current modulation, longitudinal-TCM, angular-TCM between shielding scan technique using bismuth and lead glasses. As a result, radiation dose of eye is reduced 25.88% in new OB TCM technique then reference scan technique and SNR new OB TCM is 6.05 higher than bismuth shielding scan technique and lower than reference scan technique. In clinical brain CT, new OB TCM technique will contribute to reduction of radiation dose for eye without decrease of image quality.

• Journal of the Korea Convergence Society
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• v.8 no.9
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• pp.211-216
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• 2017

The purpose of this study is to evaluate the usefulness of a newly fusion model designed cloak shield to reduce the radiation exposure of the assistant during CT(computed tomography) of severely injured patient. Radiation dose was measured in the heart, both axillary and thyroid areas using newly designed cloak shield and existing shield with head phantom and human phantom under the same conditions as brain vascular CT scan. The newly designed cloak shield was measured higher for radiation shielding rate than the existing shields, 61.9 % for heart, 46.2 % for left axillary, 69.8 % for right axillary and 71.1 % for thyroid gland, respectively. a newly developed fusion model of cloak shields are useful for reducing radiation exposure. It is expected to make a significant contribution to reduction of radiation exposure.

• Journal of Radiation Protection and Research
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• v.47 no.2
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• pp.86-92
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• 2022

Background: The present study investigated the radiation dose distribution of balloon kyphoplasty (BKP) among surgeons and medical staff, and this is the first research to observe such exposure in Japan. Materials and Methods: The study subjects were an orthopedic surgeon (n = 1) and surgical staff (n = 9) who intervened in BKP surgery performed at the National Hospital Organization Disaster Medical Center (Tokyo, Japan) between March 2019 and October 2019. Only disposable protective gloves (0.022 mmPb equivalent thickness or less) and trunk protectors were used, and no protective glasses or thyroid drapes were used. Results and Discussion: The surgery time per vertebral body was 36.2 minutes, and the fluoroscopic time was 6.8 minutes. The average exposure dose per vertebral body was 1.46 mSv for the finger (70 ㎛ dose equivalent), 0.24 mSv for the lens of the eye (3 mm dose equivalent), 0.11 mSv for the neck (10 mm dose equivalent), and 0.03 mSv for the chest (10 mm dose equivalent) under the protective suit.The estimated cumulative radiation exposure dose of 23 cases of BKP was calculated to be 50.37 mSv for the fingers, 8.27 mSv for the lens, 3.91 mSv for the neck, and 1.15 mSv for the chest. Conclusion: It is important to know the exposure dose of orthopedic surgeons, implement measures for exposure reduction, and verify the safety of daily use of radiation during surgery and examination.

• Journal of radiological science and technology
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• v.7 no.1
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• pp.23-33
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• 1984

In the present study, we determined reduction value of radiation on chest film by film method and made a reduction curves. The reduction radio in exposure to radiation was induced by comparative investigation of characteristic curves and reduction one. Basing on these result, we could reduce a radiation dose on body surface in 50% at the time of chest radiography, if 17.8mm aluminium or 0.87mm copper filter were used in addition to conventional filter at 140KV tube voltage. The present study further revealed that the additional use of the aluminium or copper filter at the time of high voltage radiography in chest facilitates to identify an image of some pathologic focus overlapping wist clavicle and ribs.

• Journal of Ginseng Research
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• v.35 no.3
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• pp.261-271
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• 2011

Chemical radiation protection is an important strategy to protect living beings against the deleterious effects of radiation. In the present study, the radioprotective effect of hydro-alcoholic extract of Panax ginseng extract (PGR-HAE) was studied on radiation-induced deleterious alterations in Swiss albino mice. Oral administration of such extract (25 mg/kg b wt/day/animal) for 5 consecutive days, half an h. before whole-body exposure to 6 Gy gamma radiation, enhanced the 30 days survival and also inhibited the radiogenic sickness, weight loss and life shortening. PGR-HAE ameliorated radiation induced depletion in blood constituents at different necropsy intervals between 12 h to 30 d, and significantly increased the number of femoral spleen colony forming units that survived after irradiation. Furthermore, it checked depletion of glutathione and antioxidant enzymes (superoxide dismutase, catalase, and glutathione S-transferase) as well as elevation of lipid peroxidation (LPO) level in blood and liver. The significant reduction in the yield of LPO demonstrates that PGR-HAE protects the membranes against radiation-induced oxidative damage. These findings conclude that such plant extract provides significant radioprotection, and it may be potentially valuable in the prevention of injuries caused during planned and unplanned radiation exposure.

• Journal of Radiation Protection and Research
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• v.28 no.2
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• pp.145-154
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• 2003

By optimizing the radiation protection the collective dose and individual dose could be reduced during YGN #4 $5^{th}$ outage in 2001. The collective doses for the two high radiation jobs decreased to 85% and 65% of expected doses. The proportion of workers with low dose (below 1mSv) exposure increased 4% while the proportion of workers with over 3mSv and 5mSv exposure are decreased to 2%, 1% respectively. But none is exposed over 8mSv for the annual dose. To aid decision of utilizing the robot, cost- benefit analysis was performed and reasonable point was proposed to use the robot. For the first time job, repeated ALARA meeting and mock up training were implemented to set up working procedure by identifying the trouble. To easily set up standard procedure, mockup process was videotaped and reviewed during ALARA meeting. Monitoring is a good approach to chase radiological working condition such as working time, dose rate. behavior of workers, especially for high radiation work. Those data were estimated and adjusted from the stage of work planning to mock up. At the stage of actual work the monitoring data were compared to the estimation and recorded to database. This database will not only be used as a powerful tool for dose optimization at the following outage but also as a guideline to dose constraint set up for optimization for each specific situation.