• Asian Pacific Journal of Cancer Prevention
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• v.14 no.2
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• pp.801-803
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• 2013

Intraduction: There is known to be a relationship between vitamin D level and more aggresive breast cancer subtypes, especially triple-negative breast cancer (TNBC). It was reported that sunlight exposure has an effect on the prognosis of patients with cancer, possibly related to the conversion of vitamin D to its active form with sunlight. We aimed to evaluate the effect of sunlight exposure on patients with TNBC. Materials-Methods: A total of 1,167 patients with breast cancer from two different regions of Turkey (Antalya and Kayseri, regions having different climate and sunlight exposure intensity over the year) were analysed retrospectively. The ratio of patients with TNBC was identified in those two regions. Results: The ratio of patients with TNBC was 8% and 12% for Kayseri and Antalya regions, respectively, and this difference between the two groups was statistically significant (p=0.021). Discussion: Sunlight exposure may be associated with more prevalent TNBC. This finding should be investigated with a prospective study.

• Journal of Radiation Protection and Research
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• v.37 no.2
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• pp.96-102
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• 2012

International Commission on Radiological Protection (ICRP) has revised its recommendations concerning the tissue reaction to ionizing radiation in accordance with consideration of the detriment arising from non-cancer effects of radiation on health based on recent epidemiological basis. Particularly, for the lens of the eye, the threshold in absorbed dose revised to be 0.5 Gy, for occupational exposure in planned exposure situation the commission recommended "An equivalent dose limit for the lens of the eye of 20 mSv in a year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv." To monitor the radiation exposure of radiation worker, TLD is typically provided and the lens of eye dose can be assessed by run of dose calculation algorithm with TL element response data. This study is to assess equivalent dose of the lens of eye using the Harshaw TLD system and its two different dose calculation algorithms. The result provides the Harshaw TLD system showed the assessment of the lens of eye dose with 48.84% error range.

• Journal of the Korean Society of Radiology
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• v.12 no.4
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• pp.459-466
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• 2018

Risk of radiation worker and radiation workplace are being mainly assessed by exposure dose. But, the radiation used in radiation workplace and the work environment are different. Because the nondestructive work environment varies depending on the work subject, the existence and nonexistence of shielding board, and so on. So, we need to consider the various factors in effective radiation protection aspect. We conducted a survey of radiation workers with over two years' experience in NDT workplace and heared the thoughts of experts. As a result, radiation source, exposure dose, current status of workplace management, workers with personel dosimetry problem and status of periodic regulatory inspection were chosen as main factors of radiation risk index model. Also, we primarily set weighting factors in order of importance based on questionnaires. Finally, we determined weighting factor for details of main factors through the professional advice. Therefore, we will be able to develop the radiation risk index model for assessing the risk of nondestructive test workplace based on main factors that are selected through this study.

• Journal of radiological science and technology
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• v.30 no.3
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• pp.213-219
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• 2007

The purpose of this study is to evaluate shielding effect of radiation protector for interventional radiologists in procedures by measuring inside and outside of radiation protector. In this study, we measured the radiation dose of 4 interventional radiologists during TACE and PTBD procedure for 4 month(2005.05-2005.09). Absorbed dose were measured by TLD placed underneath and over radiation protector such as Goggle, Thyroid protector, Apron and placed on the 4th finger of Hand. In addition, we measured background radiation dose in the control room using TLD. During TACE procedure, using 0.07 mmPb Goggle decreased average 53.8% of radiation dose rate in continuous fluoroscopic mode and decreased average 77.6% of radiation dose rate in pulse fluoroscopic mode. Using 0.5 mmPb Thyroid protector decreased average 88.9% of radiation dose rate in continuous fluoroscopic mode and decreased average 92.8% in pulse fluoroscopic mode. During PTBD procedure, using 0.07 mmPb Goggle decreased radiation dose rate average 62.7%, 87.9% by 0.5 mmPb Thyroid protector, 90.5% by 0.5 mmPb Apron. The average fluoroscopic time of PTBD was 6.14 min. shorter than TACE procedure, but radiation exposure dose rate of PTBD was 3 times higher in total body dose, and 40 times higher in hand dose rate than TACE. Interventional radiologists must wear thicker protector recommended over 0.5 mmPb. Also, they must use lead Goggle during interventional procedure. Abdomen dose decreased average 38.4% by drawing a lead curtain under the patient's table, therefore, they must draw a lead curtain to shield scattering ray. Radiation exposure dose decreased average 59.0% by using pulse fluoroscopic mode. So radiologists would better use pulse fluoroscopic mode than continuous fluoroscopic mode to decrease exposure dose.

• Archives of Plastic Surgery
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• v.50 no.1
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• pp.59-62
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• 2023

A 57-year-old man presented with a pigmented papule, 0.4 cm in diameter, on the left lower eyelid. Skin biopsy revealed a basal cell carcinoma, which was excised through a wide excision followed by a full-thickness skin graft (FTSG). Two weeks after the surgery, an erythematous nodule developed in the lower margin of the graft recipient site. The nodule size increased rapidly over 2 weeks, becoming dome-shaped with a central hyperkeratotic plug. A diagnosis of keratoacanthoma (KA) was made, and surgical excision was performed. Histological findings revealed a large, well-differentiated squamous tumor with a central keratin-filled crater and buttress. The human papilloma virus (HPV) genotyping results were negative. Risk factors for KA include trauma, old age, exposure to ultraviolet (UV) radiation, immunosuppression, and HPV infection. KA has most often been reported to develop at the donor site. Although the pathogenesis of KA is unclear, trauma is believed to act as a second insult to a preceding oncogenic insult, such as exposure to UV radiation, resulting in a koebnerization. Herein, we report a case of solitary KA at a FTSG recipient site. This report presents information that may provide guidance during dermatologic surgeries.

• Journal of radiological science and technology
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• v.42 no.6
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• pp.469-476
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• 2019

The purpose of this study examines the education, knowledge and behavior of radiation safety management among dental workers and compares the education, knowledge and behavior between dental hygienist group and other occupational groups. This study was conducted from November 2nd to November14th, 2019. The survey was conducted on dental workers(dental hygienists, nursing, assistants, coordinators, etc.) who worked in dental hospitals and clinics in Busan area. The tool of this study was modified and adapted to the clinical setting based on the questionnaire. Radiation safety education has 39 dental hygienists who had more education than non-dental hygienists (p=0.286). The most common types of radiation safety education were self-education which usually performed by dentistry, followed by conservative education and others. The average of radiation attitudes, knowledge and behaviors was higher in the dental hygienist group then in the non-dental hygienist group. On the item-specific behavior among employees, the question of 'the radiation should be shielded according to the menstrual cycle or pregnancy of the woman of childbearing' was significant (p<0.05). On the item-specific knowledge between occupations, the question of 'the intensity of X-rays decreases over distance' and 'the individual exposure can be measured by TLD badge or film badge' was significant (p<0.05). Taken together, these results indicate that the dental hygienist group is more concerned about radiation safety and that the dental hygienist group is receiving more radiation safety management training. However, if there is a low level of 'has experienced' in the presence or absence of safety management education, it is difficult to train radiation safety management in dentistry. Therefore, it is considered that dentists should be trained in radiation safety management periodically to pay attention to radiation safety accidents.

• Radiation Oncology Journal
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• v.1 no.1
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• pp.95-102
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• 1983

The radical treatment of uterine cervical cancer by interacavitary radium or cesium, in combination with teletherapy are well known. Although the result of such treatment should not give rise to complacency, problem of radiation exposure to medical staff had not been resolved. Fortunately, many attempts have been made to reduce this hazard, most of which take the form of afterloading applicators with a suitably shielded radioisotope. In order to avoid hazardous radiation exposure to staffs concerned with brachytherapy, RALS using high intensity source of Co-60, have been employed at Yonsei Cancer Center since May, 1979. It allows rectal and bladder doses to be kept low, while maintaining a satifactory usual dose distribution of the other type of applicators, and the short treatment time allow four or five patients to be treated per hour. It also removes much patient's discomfort and the difficulties of nursing these patients. Since the first introduction in Korea, over seven hundred cases with various stage of uterine cervical cancer have been treated on a radical basis at this center last 4 years. These authors have strongly attracted attention to the results in terms of local control rate, survival s and morbidity compared with those of conventional low dose rate radiotherapy. Retrospective interim analysis of data was preliminarily accomplished through the labored follow-up study of 340 cases treated during initial 2 years and the radiobiologic standpoint of high dose rate intracavitary irradiation will be discussed.

• Journal of the Korean Society of Radiology
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• v.17 no.7
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• pp.1025-1031
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• 2023

We aimed to evaluate the radiation dose and image quality by changing the Scout view voltage in low-dose chest CT (LDCT) and applying scan parameters such as AEC (auto exposure control) and ASIR (adaptive statistical iterative reconstruction) to find the optimal protocol. Scout view voltage was varied at 80, 100, 120, 140 kV and after measuring the dose 5 times using the existing low-dose chest CT protocol, the appropriate kV was selected for the study using the Dose report provided by the equipment. After taking a basic LDCT shot at 120 kV, 30 mAs, ASIR 50% was applied to this condition. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were assessed by measuring Background noise (B/N). For dose comparison, CTDI_vol and DLP provided by the equipment were compared and analyzed using the formulas. The results indicated that the protocol of scout 140 + LDCT + ASIR 50 + AEC reduced radiation exposure and improved image quality compared to traditional LDCT, providing an optimal protocol. As demonstrated in the experiment, LDCT screenings for asymptomatic normal individuals are crucial, as they involve concerns over excessive radiation exposure per examination. Therefore, applying appropriate parameters is important, and it is expected to contribute positively to the public health in future LDCT based health screenings.

• Journal of the Korean Society of Radiology
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• v.7 no.1
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• pp.25-30
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• 2013

In this work, we investigate the statistical properties of gamma exposure rates using well-known analysis methods, such as Autocorrelation Function Analysis(ACF), Rescaled Range Analysis(R/S Analysis), and Detrended Fluctuation Analysis(DFA). Especially, DFA is an important method to reliably detect long-range correlations in non-stationary time series. Our data are measured by Gangneung regional radiation monitoring station over the period of 1998 to 2011. First, we find a crossover indicating two different governing regimes in fluctuations of gamma exposure rates. Within a year, they show a strong long-ranged memory while this property vanishes over the range of time period longer than one year. Second, our finding is very securely supported by a variety of analysis tools. Those tools yield many relevant exponents which satisfies the well known relation between them.

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.667-674
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• 2019

Because examination with technegas produces images through simple diffusion accumulation, the examination room can become contaminated after scan. Therefore, radiation workers and patients awaiting examination will be affected by internal exposure from technegas inhalation. Before and after gravity ventilation, I am trying to find a way to reduce the exposure dose of waiting patients according to a comparative analysis of horizontal spatial dose rates over time. Spatial dose ratio were measured for 10 minutes from various distances and angles around ventilator's location before and after gravity ventilation. Then, mean values, standard deviation and reduction ratio were calculated. The highest reduction rate of gravity ventilation was 95.31% and the highest reduction ratio was 1 to 3 minutes. Therefore, the gravity ventilation could reduce the exposure dose of radiologic technologists, waiting patients, patient guardians and nurses. In conclusion, the reduction of the exposure dose during the technegas ventilation study through gravity ventilation will play a role in optimiging the protection and it is in accordance with the recommended reduction of the medical exposure by ICRP 103.