• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2017년도 춘계 종합학술대회 논문집
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• pp.307-308
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• 2017

방사선구역내의 종사자 간의 피폭선량 비교와, 동일한 구역내에서 임상실습에 임하는 학생들의 선량을 비교하여 방사선방어의 최적화에 대한 기초자료를 제공하고자 하였다. 연구대상은 2016년 1월부터 동년 12월까지 C대학병원 방사선관리구역에 재직중인 방사선관계종사자 121명과 방사선작업종사자 36명, 그리고 8주간의 임상실습을 이수한 121명의 학생을 비교 대상으로 하였다. 방사선관계종사자와 작업종사자 간의 평균 심부 및 표층선량은 관계종사자가 각각 $.7440{\pm}1.676mSv$와 $.7753{\pm}1.730mSv$ 가장 높게 나타났으며, 통계적으로 매우 유의하였다(p<.01). 3그룹간에는 심부선량의 경우 임상실습학생이 $.143{\pm}.136mSv$로 가장 높게 나타났고, 표층선량에서도 $.1513{\pm}.139mSv$로 가장 높게 나타났으며, 작업종사자가 두 경우 모두 가장 낮았으며, 그룹간의 평균의 차이는 통계적으로 매우 유의하였다(p<.01). 결론적으로 ALARA 원칙에 의거 철저한 관리가 필요하며, 특히 방사선안전관리의 사각지대에 놓여 있는 임상실습 학생에 대한 체계적인 피폭선량 관리가 필요할 것으로 사료된다.

• Radiation Oncology Journal
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• 제36권4호
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• pp.265-275
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• 2018

Cancer is a complex multifaceted illness that affects different patients in discrete ways. For a number of cancers the use of chemotherapy has become standard practice. Chemotherapy is a use of cytostatic drugs to cure cancer. Cytostatic agents not only affect cancer cells but also affect the growth of normal cells; leading to side effects. Because of this, radiotherapy gained importance in treating cancer. Slaughtering of cancerous cells by radiotherapy depends on the radiosensitivity of the tumor cells. Efforts to improve the therapeutic ratio have resulted in the development of compounds that increase the radiosensitivity of tumor cells or protect the normal cells from the effects of radiation. Amifostine is the only chemical radioprotector approved by the US Food and Drug Administration (FDA), but due to its side effect and toxicity, use of this compound was also failed. Hence the use of herbal radioprotectors bearing pharmacological properties is concentrated due to their low toxicity and efficacy. Notably, in silico methods can expedite drug discovery process, to lessen the compounds with unfavorable pharmacological properties at an early stage of drug development. Hence a detailed perspective of these properties, in accordance with their prediction and measurement, are pivotal for a successful identification of radioprotectors by drug discovery process.

• 한국방사선학회논문지
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• 제17권2호
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• pp.249-255
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• 2023

본 연구는 방사선작업종사자, 방사선관계종사자 그룹의 방사선사들과 수시출입자로 분류된 예비 방사선사인 재학생의 임상실습 과정에서의 피폭선량을 측정하였다. 2021년 1월부터 1년 동안 인천소재의 C 대학병원의 방사선구역에서 근무하였던 방사선사들과 동 의료기관에서 7월 1일부터 8월 31일까지 임상실습을 이수한 121명의 학생들을 연구대상으로 하였다. 방사선 피폭선량으로 인하여 손상위험장기인 폐의 피폭선량으로 인한 부작용 발생확률을 평가하기 위하여 ICRP 103^[12]에 의거한 명목위험계수(Nominal Risk Factor)를 사용하였다. 임상실습기간 중 수시출입자로 분류된 방사선(학)과 학생들의 표층선량은 0.98 ± 0.14 mSv, 심부선량은 0.93 ± 0.14 mSv였다. 즉, 표층선량은 1,000,000당 6.7명, 심부선량은 6.4명이 폐의 피폭선량으로 인한 부작용 발생률이 있음이 나타났다. 이는 1년 피폭선량의 환산 값으로 방사선(학)과 교육과정이 3년 혹은 4년임을 고려하였을 때, 임상실습을 나가는 예비 방사선종사자들에 대한 체계적인 관리와 관심이 필요하며, 방사선의 확률적 영향과 관련하여 방사선 안전관리를 위한 기초자료로 활용될 것으로 사료된다.

• 한국의학물리학회지:의학물리
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• 제17권1호
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• pp.24-31
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• 2006

유방암 환자의 방사선치료에 있어 치료도중(intrafractional) 및 분할 치료 간(intefractional)에 발생되는 오차를 측정하는 자동분석소프트웨어를 개발하였다. 오차 분석 결과는 3차원 입체조형 방사선치료를 임상에 적용하기에 앞서 적절한 치료계획용적(Planning Target Volume, PTV)을 설정하는 데 있어 매우 중요하다. 본 연구에서는 전자포탈영상장치(Electrical Portal imaging Device, EPID)로써 Portal Vision LC250 액체 충전형 이온화 검출기를 사용하였다(fast frame-averaging 모드, 초당 1.4 프레임, 256X256 픽셀). 12명의 환자에 대해 최소 7일 이상씩 영상을 획득하였다. 매 치료마다 평균 8 내지 9개의 영상을 각 빔에 대해 얻었다(분당 400 MU 선량률). 총 2,931 (720 측정을 포함하는)개의 영상을 정량적으로 분석할 수 있는 자동화 영상 분석 소프트웨어를 개발하였다. 이를 통해 호흡으로 인해 발생하는 치료도중 오차와 분할 치료간 발생하는 분할치료오차의 표준편차($\sigma$)들을 계산하였다. 신뢰 구간 95%로 임상표적체적(Clinical Target Volume, CTV)을 포함할 수 있는 PTV 마진은 $2\;(1.96\;{\sigma})$으로 계산되었다. 주로 호흡으로 인해 유발되는 치료도중오차를 보상하기 위해 필요한 PTV 마진은 2 mm에서 4 mm이었다. 반면에 분할 치료간 오차를 보상하기위해 필요한 PTV 마진은 7 mm에서 31 mm이었다. 12명의 환자에 대한 전체 평균오차는 17 mm이었다. 분할치료 간 오차는 호흡에 의해 유발되는 치료도중 오차에 비해 2배에서 15배까지 더 크게 나타났다. 유방암 치료에 있어 3차원 입체정형조사나 세기조절방사선치료(Intensity Modulated Radiation Therapy, IMRT)를 적용하기에 앞서 반드시 셋업 오차의 크기를 측정하여 PTV에 적절히 반영되어야 한다. 유방에 대한 3차원 입체정형조사나 세기조절방사선치료를 위해 반드시 필요한 것은 아니지만, 큰 PTV 마진을 줄여주기 위해서는 영상유도방사선치료(Image Guided Radiation Therapy, IGRT)가 매우 유용하게 이용될 수 있다. 전자포탈영상장치 들은 본 보고서에서 기술한 바와 같은 자동분석소프트웨어를 반드시 포함하여야 한다. 이를 통해 수많은 EPID 영상들을 자동화 처리하고 오차분석을 시행함으로써 각 병원의 임상적용 방법 및 환경에 따라 상이하게 나타날 수 있는 오차의 크기를 감안한 적절한 PTV마진을 구하는데 도움을 얻을 수 있다. 이러한 장치들은 또한 최소의 노력으로 환자 치료를 관찰할 수 있는 귀중한 정보를 제공해 준다.

• 한국간담췌외과학회지
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• 제28권2호
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• pp.161-202
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• 2024

Backgrounds/Aims: Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021. Methods: Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop. Results: In November 2021, the finalized draft was presented for public scrutiny during a formal hearing. Conclusions: The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

• Radiation Oncology Journal
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• 제37권3호
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• pp.176-184
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• 2019

Purpose: It is unclear whether adding concurrent chemotherapy (CT) to definitive radiotherapy (RT) following induction CT is a tolerable and cost effective treatment for non-small-cell lung cancer (NSCLC) patients aged 70 years or older with comorbidities. This study evaluated the actual clinical outcomes between concurrent chemoradiotherapy (CCRT) and RT alone following induction CT or not in patients (≥70 years) in a single institution's clinical practice. Materials and Methods: A total of 82 patients with unresectable stage III NSCLC between 2004 and 2016 were retrospectively analyzed. Their treatment tolerance and clinical outcomes such as overall survival (OS), locoregional recurrence (LRR), treatment toxicities and distant metastasis (DM) were evaluated. Early mortality rates were also evaluated as 4-month mortality after RT. Results: Fifty-four patients received CCRT and 28 patients received RT alone. Induction CT before RT was performed for 68.5% and 50.0% in CCRT and RT alone groups. Treatment tolerance was significantly worse in CCRT (p = 0.046). The median survival was 21.1 and 18.1 months for CCRT and RT alone, which was not statistically significant. LRR and DM were also not different. Most early deaths after CCRT were attributed to non-cancer-related mortality. Acute esophagitis of grade ≥2 occurred more following CCRT (p = 0.017). In multivariate analysis, a Charlson Comorbidity Index (CCI) of ≥5 and a weight loss of ≥5% after RT were associated with poor OS. The factors adversely affecting 4-month survival were a CCI of ≥5 and CCRT. Conclusion: There were no significant differences in OS, LRR, and DM between CCRT and RT alone treatment in elderly patients. However, there was a poorer tolerance and higher incidence of acute esophagitis in the CCRT group. Specifically, when the patients had a CCI of ≥5, RT alone seems to be reasonable with a low probability of early death.

• 대한방사선기술학회지:방사선기술과학
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• 제41권1호
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• pp.39-45
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• 2018

The purpose of this study is to evaluate the usefulness of a software-based quality assurance system based on Volumetric Modulated Arc Therapy treatment plan. Evaluate treatment plan through the D VH analysis, PTV mean dose ($D_{mean}$) and PTV 95% dose($D_{95}$) compare the MFX based on original treatment plan, Average error rate was $0.9{\pm}0.6%$, $1.0{\pm}0.8%$, respectively. Measuring point dose using phantom and ion chamber, the average error rate between the ionization chamber and MFX was $0.9{\pm}0.7%$, $1.1{\pm}0.7%$ (high dose region), $1.1{\pm}0.9%$, $1.2{\pm}0.7%$ (low dose region). The average gamma though of MFX and $Delta^{4PT}$ is $98.7{\pm}1.2%$, $98.4{\pm}.3%$, respectively. Through this study, A software based QA system that simplifies hardware based QA procedures that involve a lot of time and effort. It can be used as a simple and useful tool in clinical practice.

• Journal of Yeungnam Medical Science
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• 제36권1호
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• pp.36-42
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• 2019

Background: The purpose of this study was to evaluate the efficacy and feasibility of non- coplanar whole brain radiotherapy (NC-WBRT) for parotid sparing. Methods: Fifteen cases, previously treated with WBRT were selected. NC-WBRT plans were generated. The beam arrangement for the non-coplanar plans consisted of superior anterior, right, and left beams. After generation of the non-coplanar plans a field-in-field technique was applied to the bilateral parallel opposed beams in order to reduce maximum dose and increase dose homogeneity. The NC-WBRT plans were subsequently compared with the previously generated bilateral WBRT (B-WBRT) plans. A field-in-field technique was also used with the B-WBRT plans according to our departmental protocol. As per our institutional practice a total dose of 30 Gy in 10 fractions of WBRT was administered 5 days a week. Results: The mean dose to the parotid gland for the two different plans were 16.2 Gy with B-WBRT and 13.7 Gy with NC-WBRT (p<0.05). In the NC-WBRT plan, the V5Gy, V10Gy, V15Gy, V20Gy, and V25Gy of the parotid were significantly lower (p<0.05) than those of the B-WBRT plan. The $D_{max}$ of the lens was also lower by 10% with NC-WBRT. Conclusion: The use of NC-WBRT plans could be a simple and effective method to reduce irradiated volumes and improve the dose-volume parameters of the parotid gland.

• 한국의학물리학회지:의학물리
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• 제24권4호
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• pp.205-212
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• 2013

Cone Beam CT (CBCT)와 On Board Imaging (OBI)를 비롯하여 최근에 개발되고 있는 방사선 치료용 영상 장치(Image Guided Radiation Therapy, IGRT)의 사용으로 방사선 치료가 더욱 정확해지고 있다. 점차 사용 범위가 넓어지면서 표준치료법으로 자리잡았고 앞으로 사용하는 기관과 빈도가 더 늘어날 것으로 전망한다. IGRT는 그러나 안전하고 용도에 맞게 사용할 때만 효능을 볼 수 있다. 이를 위해 IGRT를 임상에 적용하기 전에 장치의 특성을 이해하고 병원의 임상 요구에 적합한 지침서를 미리 만들 필요가 있다. QA 프로그램과 환자가 받을 추가 선량에 대한 고려도 미리 준비해둘 필요가 있다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2875-2878
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• 2014

Background: Lung cancer is one of the commonest and most lethal cancers throughout the world. The majority of the patients present at advance stage and are not suitable for curative intent treatment. Even among patients with localized disease, there has been underutilization of curative treatment modalities. The aim of this study was to analyze the radical treatment utilization rates in patients with non small cell lung cancer (NSCLC) treated at our centre. Materials and Methods: We analyzed case records of 104 patients with a pathologically confirmed diagnosis of NSCLC having stage 1-3B disease who were treated at our centre over last 3 years, to assess the utilization of curative treatment modalities i.e. surgery or radical radiotherapy. Results: The median age of this cohort was 58 years. Out of 104 patients only 33 (31.7%) received curative intent treatment, 14 undergoing curative resection and 19 receiving radical doses of radiotherapy. The baseline characteristics of both the groups (with or without radical treatment) were not different. Major factors associated with underutilization with curative treatment were progressive disease or loss of follow up after chemotherapy and inappropriate use of TKI and/or palliative radiotherapy in patients with stage 1-3B disease. Patients who did not receive radical treatment had inferior PFS and OS than those who received radical treatment. Conclusions: In our practice we observed gross underutilization of curative intent treatment modalities in patients with NSCLCs which is associated with inferior survival.