• 대한두경부종양학회지
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• 제19권1호
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• pp.9-15
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• 2003

Purpose: To introduce our early experience with intensity-modulated radiotherapy (IMRT) in the treatment of nasopharyngeal carcinoma. Methods and Materials: Eight patients who underwent IMRT for no disseminated nasopharyngeal carcinoma at the Asan Medical Center between September 2001 and November 2002 were evaluate by prospective analysis. According to the 1997 American Joint Committee on Cancer staging classification, 5 had Stage III, and 3 had Stage IVB disease. The IMRT plans were designed to be delivered as a 'Simultaneous Modulated Accelerated Radiation Therapy' (SMART) using the 'step and shoot' technique with a MLC (multileaf collimator). Daily fractions of 2.2-2.5Gy and 1.9-2Gy were prescribed and delivered to the GTV and CTV and clinically negative neck node, respectively. The prescribed dose was 70A-79.0Gy to the gross tumor volume (GTV), 60Gy to the clinical target volume (CTV) and metastatic nodal station, and 46Gy to the clinically negative neck. All patients also received weekly cisplatin during radiotherapy. Acute and late normal tissue effects were graded according to the Radiation Therapy Oncology Group (RTOG) radiation morbidity scoring criteria. Results: Follow-up period was ranging from 5 to 18 months. All patients showed complete response and loco-regional control rate was 100% but one patient died of malnutrition due to treatment related toxicity. There were no Grade 3 or 4 xerostomia and all patients had experienced improvement of salivary gland function. Conclusion: 'Simultaneous Modulated Accelerated Radiation Therapy' (SMART) boost intensity-modulated radiotherapy technique allows parotid sparing as evidenced both clinically and by dosimetry. Initial tumor response and loco-regional control was promising. It is clinically feasible. A larger population of patients and a long-term follow-up are needed to evaluate ultimate tumor control and late toxicity.

• Radiation Oncology Journal
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• 제28권1호
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• pp.1-8
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• 2010

목 적: 흉선종환자에서 방사선치료 효과를 평가하고 생존율에 영향을 미치는 예후인자를 파악하기 위하여 후향적 분석을 시행하였다. 대상 및 방법: 2002년 3월부터 2008년 1월까지 본원에서 흉선종으로 진단 받고 방사선치료를 시행 받은 21명의 환자를 분석하였다. 대상환자의 추적관찰 기간은 3~89개월(중앙값, 37개월)이었다. 남녀 구성비는 4：3이었고 연령분포는 24~77세(중앙값, 57세)이었다. Masaoka병기는 II기 10명(47.6%), III기 7명(33.3%), IVa기 4명(19.1%)이었다. 전체 21명 중 15명(완전절제[흉선절제술], 14명; 불완전절제, 1명)에서 수술이 시행되었고, 시험적 개흉술(exploratory thoracotomy), 경부림프절 생검 등을 포함한 조직검사만 시행한 경우는 6명(28.6%)이었다. 병리학적으로 WHO 세포형 A 1명(4.8%), B1-3 10명(47.6%), C 10명(47.6%)이었다. 방사선치료는 3차원입체조형기법으로 시행하였고 총 방사선선량은 52~70.2 Gy (중앙값, 54 Gy)이었다. 성별, 연령, 종양의 크기, 병리학적 분류, Masaoka 병기, 수술시행 여부, 근무력증 유무 및 방사선량 등에 따른 전체 및 무진행생존율의 차이를 분석하였다. 결 과: 전체 환자에서 3년 생존율은 80.7%이었고 3년 무진행생존율은 78.2%이었다. WHO 세포형 C 10명에서 완전절제를 시행한 4명 중 3명(75%)이 생존하였고, 조직검사만 시행한 6명 중 3명(50%)이 생존하였다. 수술을 시행받은 15명 중 방사선조사 범위 내에서의 재발은 없었다. 4명(19.1%)에서 원격전이가 확인되었다. 조직검사만 시행받은 6명의 치료반응은 부분관해 4명(66.6%), 불변 1명(16.7%) 그리고 진행 1명(16.7%)이었다. 치료 후 방사선폐렴이 Radiation Therapy Oncology Group (RTOG) grade 1이 1명(4.8%), grade 2가 2명(9.5%), grade 3과 grade 4가 각각 1명(4.8%) 있었다. 단변량 분석상 생존율에 유의한 예후인자는 연령(60세 이상, 58.3%; 60세 미만, 100%; p=0.0194), 병리학적 분류(WHO 세포형 A-B3, 100%; C, 58.3%; p=0.0194), 수술시행여부(시행, 93.3%; 미시행, 50%; p=0.0096)이었다. 결 론: 수술 후 보조적으로 방사선치료를 시행 받은 15명 모두 방사선치료 조사야 내 재발이 없었고 WHO 세포형 C에서 방사선치료 전 수술이 시행된 경우 조직검사만 시행된 경우보다 좋은 성적을 보였다. 이에 저자들은 흉선종 환자들을 대상으로 한 방사선치료 경험을 보고하는 바이다.

• Radiation Oncology Journal
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• 제37권4호
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• pp.259-264
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• 2019

Purpose: Accurate localization of the lumpectomy cavity during accelerated partial breast radiation (APBR) is essential for daily setup to ensure the prescribed dose encompasses the target and avoids unnecessary irradiation to surrounding normal tissues. Three-dimensional ultrasound (3D-US) allows direct visualization of the lumpectomy cavity without additional radiation exposure. The purpose of this study was to evaluate the feasibility of 3D-US in daily target localization for APBR. Materials and methods: Forty-seven patients with stage I breast cancer who underwent breast conserving surgery were treated with a 2-week course of APBR. Patients with visible lumpectomy cavities on high quality 3D-US images were included in this analysis. Prior to each treatment, X-ray and 3D-US images were acquired and compared to images from simulation to confirm accurate position and determine shifts. Volume change of the lumpectomy cavity was determined daily with 3D-US. Results: A total of 118 images of each modality from 12 eligible patients were analyzed. The average change in cavity volume was 7.8% (range, -24.1% to 14.4%) on 3D-US from simulation to the end-of-treatment. Based on 3D-US, significantly larger shifts were necessary compared to portal films in all three dimensions: anterior/posterior (p = 7E-11), left/right (p = 0.002), and superior/inferior (p = 0.004). Conclusion: Given that the lumpectomy cavity is not directly visible via X-ray images, accurate positioning may not be fully achieved by X-ray images. Therefore, when the lumpectomy cavity is visible on US, 3D-US can be considered as an alternative to X-ray imaging during daily positioning for selected patients treated with APBR, thus avoiding additional exposure to ionizing radiation.

• Journal of Radiation Protection and Research
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• 제18권1호
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• pp.37-51
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• 1993

본 연구에서는 환기장치로 제어하는 환경인 라돈 표준실 및 라돈 발생기로부터 이론적으로는 Jacobi모델 이론을 사용하여 라돈 자핵종의 농도를 계산하였으며, 실험적으로는 두 발생 조건으로부터 채취된 시료를 알파스펙트럼 분석법에 의해 측정 분석하여 그 농도를 결정하였다. 이론적인 계산치와 실험적인 측정결과를 비교해 본 결과 매우 잘 일치되는 좋은 결과를 얻게 되었다. 따라서 이러한 연구는 실내 라돈환경에서 라돈 자핵종의 알파방출체에 의한 내부피폭선량을 보다 정확히 평가하고, 라돈 자핵종의 개별 농도를 신속히 결정하는 데 크게 기여할 것이라 사료된다.

• Nuclear Engineering and Technology
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• 제54권8호
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• pp.2871-2876
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• 2022

The sensitivity of polymer-based capacitive relative humidity (RH) sensors after irradiation with neutrons, electrons and protons was measured. Degradation consists of the decreasing of the upper RH limit that can be measured. At the same time, low RH-level sensitivity is almost stable. After 30 krad of absorption dose, RH cut off is equal to 85% of max value, after 60 krad-40%. Degradation reduces after annealing which indicates high radiation sensitivity of the internal circuit in comparison to RH-sensing polymer film.

• Radiation Oncology Journal
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• 제1권1호
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• pp.41-45
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• 1983

To obtain 7 MeV electron beam which is suitable for treatment of the chest wall after radical of modified radical mastectomy, the authors reduced the energy of electron beam by means by Lucite plate inserted in the beam. To determine the proper thickness of the Lucite plate necessary to reduce the energy of 9 MeV electron beam to 6 MeV, dosimetry was made by using a parallel plate ionization chamber in polystyrene phantom. Separation between two adjacent fields, 7 MeV for chest wall and 12 MeV for internal mammary region, was studied by means of film dosimetry in both polytyrene phantom and Humanoid phantom. The results were as follows. 1. The average energy of 9 MeV electron beam transmitted through the Lucite plate was reduced. Reduction was proportional to the thickness of the Lucite plate in the rate of 1.7 MeV/cm. 2. The proper thickness of the Lucite plate necessary to obtain 6 MeV electron beam from 9 MeV was 1.2 cm. 3. 7 MeV electron beam, 80% dose at 2cm depth, is adequate for treatment of the chest wall. 4. Proper separation between two adjacent electron fields, 7 MeV and 12 MeV, was 5mm on both flat surface and sloping surface to produce uniform dose distribution.

• Journal of Radiation Protection and Research
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• 제14권1호
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• pp.34-45
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• 1989

프랑스의 1300 MWe 급(級) 표준(標準) P'4형 PWR 원전(原電)의 일차냉각재상실사고(一次冷却材喪失事故)(LOCA)시(時) 원전(原電) 주제어가내(主制御家內) 운전원(運轉員)에 대한 고사선(故射線) 피습선량(被濕線量)을 계산하여 주제어실(主制御室)의 체류안전성(滯留安全性)을 평가(評價)하였다. 본(本) 평가(評價)에서 사용(使用)된 제가정(諸假定)은 프랑스의 표준안전성분석보고서(漂準安全性分析報告書)에 따랐다. 본(本) 평가(評價)를 위하여 LOCA 사고시(事故時) 원자로건물외(原子爐建物外)로 방출(放出)되는 방사핵종(放射核種)의 방사능(放射能), 주제어실(主制御室)에서의 체적인자(體積因子) 및 제어실내(制御室內) 운전원(運轉員)의 전신(全身) 및 갑상선(甲狀膳) 피폭선량(被爆線量)을 사고발생후(事故發生後) 30일까지 전산(電算)할 수 있는 간단한 전산(電算)프로그램, COREX를 개발(開發)하였다. 본(本) 연구(硏究)에서 얻어진 계산결과(計算結果)는 대체적으로 프랑스의 EDF(불란서 전력주식회사(電力株式會社) 에서 제안(提案)한 결과(結果)와 대체적으로 잘 일치(一致)하였으나, 전신외부피폭선량(全身外部被爆線量)의 값은 일부(一部) 체적인자(體積因子) 값의 차이로 인(因)하여 일부 편차(偏差)를 보였다.

• 방사선산업학회지
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• 제12권4호
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• pp.277-285
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• 2018

Patients administered radioisotope for medical purposes are regulated by each country to quarantine them until their body's radioactivity contents decrease below release criteria. To predict the quarantine period and provide it to medical staffs and patients, it is necessary to approach the assessment of the exposure dose of persons due to patients in a realistic manner. For this purpose, a whole-body effective half-life should be applied to the dose assessment equation instead of the physical half-life. In this study, we constructed a bio-kinetic model for each nuclear species based on the ICRP publication to obtain a whole-body effective half-life of 10 unsealed gamma-ray emitting nuclei from the notification of Nuclear Safety and Security Commission, and calculated the effective half-life mathematically by simulating the distribution of the radioisotope administered in the whole body as well as each organ scale. The whole-body effective half-life of $^{198}Au$, $^{67}Ga$, $^{123}I$, $^{111}In$, $^{186}Re$, $^{99m}Tc$, and $^{201}TI$ were 1,93, 2.57, 0.295, 2.805, 1.561, 0.245, and 2.397 days respectively. However, it was found to be undesirable to offer a single value of the effective half-life of $^{125}I$, $^{131}I$, and $^{169}Yb$ because the changes in the effective half-life show no linearity. A bio-kinetic model created for the internal exposure assessment has been shown to be possible to calculate the effective half-life of radioisotopes administered in the patient's body, but subsequent studies of radiolabeled compounds are required as well.

• Radiation Oncology Journal
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• 제26권3호
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• pp.160-165
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• 2008

목 적: 국소 진행성 폐암에서 동시 항암화학 방사선 요법이 표준 요법으로 자리 잡고 있다. 그러나 항암제의 그 사용시기와 방법에 있어서는 확립된 바가 없어서 gemcitabine, cisplatin 병용화학요법과 동시 방사선치료의 치료효과 및 안전성을 확인하였다. 대상 및 방법: 동시 항암화학 방사선요법시 gemcitabine $500\;mg/m^2$, cisplatin $30\;mg/m^2$ 요법은 2주 간격으로 환자의 순응도에 따른 방사선치료 기간의 변동을 감안해서 $3{\sim}4$회 치료하는 것을 원칙으로 하였고 흉부방사선치료는 1일 1회 1.8 Gy 씩, 주5회 분할조사 하였으며, 원발병소와 종격동 및 전이를 나타낸 림프절을 포함한 부분에 50.4 Gy를 조사 후 질환이 진행되지 않았을 경우 원발 병소에 18 Gy를 추가 조사하였다. 공고 화학요법은 3주 간격으로 $2{\sim}3$회 치료하였다. 치료반응의 판정은 동시 항암화학 방사선요법 후와 공고 화학요법 후에 각각 WHO의 판정기준에 따라 평가했다. 결 과: 29명의 대상 중, 동시 항암화학 방사선요법 후 완전관해는 1명(4%), 부분 관해는 20명(69%)이었고 공고 화학요법이 마친 후 치료 판정에서 완전 관해는 3명(10%), 부분 관해는 21명(72%)이였다. 중앙 생존 기간은 16개월($2.4{\sim}39.2$개월)이고 1년 생존율은 62.7%, 2년 생존율은 43.9%, 3년 생존율은 20%이었다. 치료 도중 독성의 빈도는 3도 이상의 과립구 감소증이 11명(37.9%)이었고 3도 이상의 식도염이 15명(51.7%)이 발생하였다. 2도 이상의 폐렴은 6명(20.7%)에서 발생하였다. 결 론: 국소진행성 비소세포폐암환자에서 gemcitabine $500\;mg/m^2$과 cisplatin $30\;mg/m^2$의 2주 간격 투여와 동시 항암화학방사선치료는 높은 치료반응률을 나타내었다. 그러나 3도 이상의 식도염과 폐렴이 예상보다 많이 관찰되어 이에 대한 부작용을 줄이기 위한 적절한 방법들이 강구되어야 할 것이며, 항암제의 용량조절, 방사선조사량의 조절과 특수 방사선치료방법들의 개발이 필요하리라고 판단되었다.

• Radiation Oncology Journal
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• 제13권1호
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• pp.27-31
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• 1995

Purpose : This study was done to evaluate preliminarily the role of intraluminal brachytherapy in the radiation treatment of non-metastatic esophageal cancer, Materials and Methods: We analyzed follow-up result of 21 patients treated at the dept. of therapeutic radiology in Gyeongsang national university hospital between April, 1989 and August, 1992. All patients received neoadjuvant chemotherapy(5-FU, Cispl-atin). Fifteen Patients were treated with external beam alone, and in remaining 6 patients, the external beam radiotherapy followed by intraluminal brachytherapy was done. Results : Among 21 patients, 7 patients showed complete tumor regression after completion of radiotherapy. But 2 of these complete responder recurred at the site of primary disease, so ultimate local control rate was $23.8\%$(5/21). Local control rate according to radiation treatment modality was $6.7\%$(1/15) in patients treaed with external irradiation only, and $66.7\%$ in patients treated with combined external irradiation and intraluminal brachytherapy. The 2 year NED survival rate was $6.6.\%$ in the former and $66.7\%$ in the latter. Conclusion: Although there should be consideration about case selection for addition of intraluminal brachytherapy intraluminal brachytherapy may be considerded as one of the method to enhance the local control probability of esophageal cancer.