• 대한방사선치료학회지
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• 제7권1호
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• pp.45-53
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• 1995

목적 : 뇌정위 방사선수술은 AVM(ateriovenous malformation)이나 작은 크기의 종양에 1회에 고선량의 방사선을 조사하는 기술이다. 선형가속기를 이용한 방사선 수술을 하기 위하여 최근 본원에 설치한 Philips SL 75-5 선형가속기와 isocentric sub system(ISS)에 의한 뇌정위 방사선 수술에 있어서 표적의 위치선정과, gantry와 couch의 회전시 기하학적 오차가 중요시 되는데 isocentric sub system의 오차를 분석 하였다. 대상 및 방법 : 방사선원으로는 Philips SL 75-5 선형가속기의 5MV 광자선을 사용하였고, 원형의 작은 광자선속을 위하여 isocenter에서의 직경이 26mm인 secondary cone을 gimbal baaring에 삽입하여 사용하였다. 표적의 크기와 좌표를 정하기 위하여 CT나 angio localizer를 이용하고, 표적좌표 선정을 위하여 BRW phantom base와 target pointer를 이용하여 임의의 BRW-coordinator를 바꾸어 가면서 gantry angle와 ISS head 각도를 임의로 바꾸어 가면서 film에 방사선을 조사하였다. 흑화된 film을 view box 위에 놓고 광학판독기구로 film 가장자리의 오차를 scale 확대경으로 측정하여 오차를 분석하였다. 결과 : 표적좌표 선정의 정확도를 확인하기 위하여 임의의 표적좌표에 gantry의 10개각도 ISShead의 10개각도에서 각각 광자선을 조사시켜 film을 이용하여 오차를 측정한 결과 collimator cone의 직경이 26mm일때 전체 평균오차가 0.219+-0.03mm이었다. 결론 : Isocentric sub system은 gantry head와 ISS arm 사이에 gimbal bearing이 있어서 이 부위를 flexible하게 연결함으로 gantry의 회전에 무관하게 정확한 isocenter를 유지시켜 주고 ISS head는 couch와 독립되어 움직이므로 isocentric sub system isocenter의 오차를 최대한 줄일수 있음을 알았다.

• Journal of Plant Biology
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• 제25권3호
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• pp.123-133
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• 1982

The tropic structure and the function of a small pone ecosystem under the tree stand were studied in terms of energy flow. About 28% of total solar radiation was intercepted by the tree canopy over the pond. Primary producers converted 1.1%(3,382 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$) of solar radiation (320,000 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$) into gross primary production. The amount of energy availble to the pond snail was 1,683 kcal.m-2.y-1 of the net production by primary producers and 1,033 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$ of the litter fallen into the pond. The amount of gross secondary production by the pond snail was 245 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$. Judging from these, supply of both net primary production and the litter was indispensable for the maintenance of the pond ecosystem. The total amont of energy as gross primary production plus litter was 4,415 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$(100%). Since the total respiration loss was calculated to be 1,917 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$(43.4%), the rate of energy accumulation in the pond estimated to 56.6%.

• 한국전기전자재료학회논문지
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• 제23권7호
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• pp.550-553
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• 2010

The enhancement of quantum efficiency using a surface modified Ag anode in top-emitting organic light emitting diodes (TEOLEDs) is reported. The operation voltage at the current density of $1\;mA/cm^2$ of TEOLEDs decreased from 9.3 V to 4.3 V as the surface of anode coated with $CuO_x$ layer. The work function of these structures were quantitatively determined using synchrotron radiation photoemission spectroscopy. Secondary electron emission spectra revealed that the work function of the Ag/$CuO_x$ structure is higher by 0.6 eV than that of Ag. Thus, the $CuO_x$ structure acts as a role in reducing the hole injection barrier by about 0.6 eV, resulting in a decrease of the turn-on voltage of top-emitting light emitting diodes.

• Asian Pacific Journal of Cancer Prevention
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• 제17권2호
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• pp.749-754
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• 2016

Extended follow-up of Hodgkin lymphoma (HL) survivors indicates that these patients are at high risk of secondary malignant neoplasms (SMNs) contributing to increased morbidity and mortality. This study examined the characteristics of HL survivors who developed SMNs with the aim to report any correlation with radiotherapy (RT) dose. In this retrospective multi-center cohort study of HL patients treated between 1990 and 2011 at three major teaching hospitals in Lebanon, classification was into two groups including those treated with combined modality (RT and chemotherapy-CHT) and those treated with CHT alone. Approval from the University Institutional Review Board (IRB) was obtained. Of the 112 patients evaluated, 52.7% (59) received the combined modality while 47.3% (53) received CHT alone. There were 6 cases of SMNs in the combined modality cohort and 5 cases in the CHT cohort. The mean RT dose in the combined modality cohort was 34.5 Gray (Gy) ($SD{\pm}5.3$). A statistically significant increase (1.5 fold) in the risk of developing SMNs was observed among patients who received a dose higher than 41 Gy compared to a dose between 20 to 30 Gy (OR= 1.5; 95% confidence interval= 0.674 to 3.339, p=0.012). The risk of SMNs was not significantly higher among patients who received extended field compared to involved field RT (p=0.964). This study showed that the risk of developing SMNs is higher among patients treated with RT dose greater than 31 Gy, independent of the RT type used.

• 대한방사선기술학회지:방사선기술과학
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• 제41권5호
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• pp.437-444
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• 2018

Whole-Body counters have been used to evaluate the internal contamination of gamma emitting radionuclides. Among the whole-body counters used in domestic nuclear facilities, Fastscan made by CANBERRA contains 2 NaI(Tl) detectors and is generally used to monitor the primary internal exposure. It has the advantage of achieving MDA even with short time measurements. Accuscan is a bed type, and has good energy resolution because it is composed of HPGe detector. Since the Accuscan with better energy resolution than Fastscan has better able to identify radionuclides, it is used to monitor secondary internal exposure. Some nuclear facilities have only Fastscan. We analyzed statistically whether Fastscan is enough to ensure accuracy and precision comparing with Accuscan. To do this, we prepared a CRM created by the Korea Research Institute of Standards and Science. We also obtained the data of 6 Fastscans and 5 Accuscans in domestic nuclear facilities. As a result of the study, although Fastscan compared with Accuscan is not as accurate as the Accuscan, the precision is statistically same. However, accuracy of Fastscan is in compliance with international standards except low energy range. In terms of accuracy and precision except radionuclides emitting low energy, it is possible to measure radioactivity inside workers even in nuclear facilities where only Fastscan is used.

• 대한암한의학회지
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• 제25권1호
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• pp.11-24
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• 2020

Objective : Radiodermatitis is a common sequelae in 95% of patients receiving radiation therapy, which is important to be well managed as it can affect the patient's quality of life as well as the cancer treatment schedule. The aim of this study is to review and summarize the interventions available for the treatment of acute radiodermatitis, including traditional Korean medicine, and to propose treatment algorithms for clinicians. Methods : To collect studies about managements for radiodermatitis, domestic and foreign database were used such as Korean journal of traditional knowledge portal (KTKP), Korean studies information service system (KISS), national discovery or science leaders (NDSL), and oriental medicine advance searching integrated system (OASIS), Pubmed, Google scholar and Scopus. Results : Thirty-two studies were selected. There were nine studies on usual care and dressing, eleven studies on chemical agents, two studies on biological preparations, and ten studies on herbal medicines. Conclusion : Hygienic options and dressings have proved to be useful in the management of radiodermatitis. Chemical agents such as corticosteroid, statin, and topical antibiotic agent have proved to alleviate symptoms and severity, regenerate damaged skin, and prevent secondary infection. In biological preparations, EGF (epidermal growth factor) and GM-CSF (granulocyte-macrophage colony-stimulating factor) could be used to protect skin and prevent radiodermatitis. For herbal medicines, Calendula, catechin, β-sitosterol, and Jaungo (紫雲膏) may be effective for symptoms including pain, itching, and burning sensation induced by radiation therapy. Because of some research with conflicting results, further studies are needed to propose an algorithm for more optimal treatments.

• 한국콘텐츠학회논문지
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• 제14권2호
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• pp.457-466
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• 2014

고 에너지 전자선 치료에 있어서 차폐물질은 종양조직 외 정상조직이나 주요장기를 보호하기 위해 사용된다. 하지만 이러한 물질에서 발생되어지는 산란선은 심부선량에 영향을 줄 수 있으며, 물질원자번호에 따라 다르게 나타난다. 이에 차폐물질로써 사용가능한 알루미늄, 구리, 납 등의 다양한 원자번호 물질을 전하 감약율 95% 되는 두께로 하여 측정과 MCNPX 모의계산으로 산란율을 비교분석하였다. 산란선 영향을 많이 받는 표면의 선량변화율은 최대 물질두께에서 +0.88%, 원자번호에서 +0.43%의 영향을 받으며, 전하 감약율 95% 되는 두께의 알루미늄, 구리, 납 물질은 측정에서 +19.70%, +15.20%, +12.40% 계산에서 +25.00%, +15.10%, +13.70%를 보였다. 이로 인해 산란율은 물질두께가 원자번호보다 많은 영향을 주며, 산란전자가 광자보다 많은 기여를 하고 있음을 알 수 있었다. 이에 임상에서의 적절한 차폐물질은 두께영향 산란선이 적게 방출되는 고 원자번호물질이 적당하다고 사료된다.

• Journal of Yeungnam Medical Science
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• 제10권1호
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• pp.212-217
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• 1993

임상적으로 많이 이용되는 범위의 방사선 조사에서는 증식능의 상실을 세포사망으로 정의를 내린다. 본 연구는 실험용 orthovoltage조사기를 이용하여 확립된 세포주인 Hela.53(5C)를 대상으로 각각 100 cGy, 200 cGy, 400 cGy 및 600 cGy 방사선조사 후 2주일간 배양후 crystal violet 염색을 하여 육안적으로 판별가능한 크기의 집락의 수를 산출하여 다음의 결과를 얻었다. HeLa.S3(SC) 세포의 집락 형성능은 0.464이었다. 세포의 생존곡선의 형태는 다표적, 1 hit 형태를 보였다. Do는 150 cGy, Dq는 80 cGy, 외삽치는 1.7이었다. 이 연구결과는 향후 다양한 방사선 생물학 연구에 참고자료로 이용 가능하리라 사료된다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제32권3호
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• pp.265-269
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• 2010

Radiation therapy for malignancy of head and neck leads to secondary effects, such as mucositis, xerostomia, dental caries and osteoradionecrosis. Osteoradionecrosis is a delayed complication which causes chronic pain, infection and constant deformity after necrosis. It occurs spontaneously or after primary oncologic surgery, dental extraction or by trauma of prosthesis. To reduce the incidence of osteoradionecrosis, appropriate antibiotic usage, atraumic procedure, tension-free primary suture and hyperbaric oxygen therapy are essential. This case is about a 74 years old woman who was treated for osteoradionecrosis after extraction of right lower molar at year 2006. She had received radiation therapy for angiosarcoma on tongue at year 2004. At year 2008 the patient came to our hospital for extraction of the opposite premolar but despite careful treatment, osteoradionecrosis occurred again. She was successfully treated by surgical procedure so we report this case.

• Journal of Hospice and Palliative Care
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• 제17권4호
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• pp.207-215
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• 2014

암의 다발성 뼈 전이는 폐암, 유방암, 전립선암, 신장암 등 다양한 암에서 흔히 관찰된다. 뼈 전이는 뼈에 발생한 이차적인 암으로 통증, 골절, 그리고 체중을 지지하는 뼈의 불안정성을 유발할 수 있어 신체활동과 삶의 질을 저하시킨다. 뼈 전이 치료 시 병리조직소견, 환자의 전신 상태, 침범 부위, 그리고 환자의 신경학적 소견등 다양한 요인을 고려하여 진통제, 수술, 항암화학요법 그리고 방사선 치료 등을 시행하게 된다. 외부 방사선 치료는 전통적으로 국소 뼈 전이로 인한 통증의 치료에 이용되어왔지만 특히 유방암이나 전립선암의 다발성 골형성 뼈 전이의 경우 $^{89}Sr$, $^{186}Re$, $^{188}Re$, $^{153}Sm$ and $^{117m}Sn$ 등의 방사성동위원소를 이용한 치료가 시행되고 있는데, 약제 투여의 간편함, 낮은 부작용, 방사능 피폭위험에서의 안전성, 높은 치료 반응 등 다양한 장점을 가진 치료로 임상에서의 유용성이 점차 증가되고 있다.