• Radiation Oncology Journal
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• 제37권4호
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• pp.302-308
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• 2019

The abscopal effect is a term that has been used to describe the phenomenon in which localized radiation therapy treatment of a tumor lesion triggers a spontaneous regression of metastatic lesion(s) at a non-irradiated distant site(s). Radiation therapy induced abscopal effects are believed to be mediated by activation and stimulation of the immune system. However, due to the brain's distinctive immune microenvironment, extracranial abscopal responses following cranial radiation therapy have rarely been reported. In this report, we describe the case of 42-year-old female patient with metastatic melanoma who experienced an abscopal response following her cranial radiation therapy for her brain metastasis. The patient initially presented with a stage III melanoma of the right upper skin of her back. Approximately 5 years after her diagnosis, the patient developed a large metastatic lesion in her upper right pectoral region of her chest wall and axilla. Since the patient's tumor was positive for BRAF and MEK, targeted therapy with dabrafenib and trametinib was initiated. However, the patient experienced central nervous system (CNS) symptoms of headache and disequilibrium and developed brain metastases prior to the start of targeted therapy. The patient received radiation therapy to a dose of 30 Gy delivered in 15 fractions to her brain lesions while the patient was on dabrafenib and trametinib therapy. The patient's CNS metastases improved significantly within weeks of her therapy. The patient's non-irradiated large extracranial chest mass and axilla mass also shrank substantially demonstrating the abscopal effect during her CNS radiation therapy. Following radiation therapy of her residual chest lesions, the patient was disease free clinically and her CNS lesions had regressed. However, when the radiation therapy ended and the patient continued her targeted therapy alone, recurrence outside of her previously treated fields was noted. The disease recurrence could be due to the possibility of developing BRAF resistance clones to the BRAF targeted therapy. The patient died eventually due to wide spread systemic disease recurrence despite targeted therapy.

• 방사선산업학회지
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• 제5권1호
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• pp.25-33
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• 2011

Skin contact allergy (SCA) is not life-threatening, but a large number of people have been suffered from the reactions caused by various kinds of chemicals and products. Thus, in this study, radiation technology was employed to improve the traditional herb addition method on the SCA reduction of Rhus verniciflua sap (RVS). Rhus verniciflua has traditionally been used as an herbal medicine plant, but its urushiol derivatives are known as a major allergen for the SCA. The present study was commenced to assess the allergenicity of both gamma-irradiated and non-irradiated RVS by using guinea-pig maximization test (GPMT) in order to probe the mechanism of an SCA. In the acute dermal irritation assays, non-irradiated RVS caused erythema, but the irradiated RVS did not provoke any erythema on the abdominal skin of the guinea pigs. From the result of the GPMT, urushiols, the main chemical components of RVS, were identified as an extreme skin sensitizer, and the removal of urushiols by irradiation extremely reduced the erythema. These results suggest that radiation technology is a novel method to reduce SCA through the removal of urushiols of RVS.

• 한국방사선학회논문지
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• 제13권2호
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• pp.233-239
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• 2019

본 연구는 방사선 비전공 대학생들을 대상으로 방사선사용에 관한 지식 및 인식을 분석하고자 설문조사를 실시하였다. 회수된 설문을 바탕으로 빈도, 평균과 표준편차, t-test, one-way ANOVA를 사용하였다. 그 결과, 방사선의 기본 지식과 사용 분야에 관한 지식 정도는 성별과 연령에서 집단 간 큰 차이는 나타나지 않았다. 전공 계열에서는 일부 항목에서 통계적 차이가 나타났다. 또한 방사선에 대한 인식에서는 여자와 25세 미만에서 더 부정적인 것으로 나타났다(p<0.05). 하부 요인 간 상관관계 분석 결과 방사선 지식이 높을수록 사용 분야의 지식과 방사선사용 인식이 높게 나타났다. 대학생들은 앞으로 사회에 진출하여 방사선 인식을 제고 하는데 영향력이 크다는 점에서 방사선에 대한 올바른 인식이 전달된다면 방사선 산업 발전에 기여하는 긍정적 효과를 나타낼 것으로 판단된다.

• Radiation Oncology Journal
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• 제33권3호
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• pp.207-216
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• 2015

Purpose: Stereotactic radiosurgery (SRS) has been introduced for small-sized single and oligo-metastases in the brain. The aim of this study is to assess treatment outcome, efficacy, and prognostic variables associated with survival and intracranial recurrence. Materials and Methods: This study retrospectively reviewed 123 targets in 64 patients with non-small cell lung cancer (NSCLC) treated with SRS between January 2006 and December 2012. Treatment responses were evaluated using magnetic resonance imaging. Overall survival (OS) and intracranial progression-free survival (IPFS) were determined. Results: The median follow-up was 13.9 months. The median OS and IPFS were 14.1 and 8.9 months, respectively. Fifty-seven patients died during the follow-up period. The 5-year local control rate was achieved in 85% of 108 evaluated targets. The 1- and 2-year OS rates were 55% and 28%, respectively. On univariate analysis, primary disease control (p < 0.001), the Eastern Cooperative Oncology Group (ECOG) performance status (0-1 vs. 2; p = 0.002), recursive partitioning analysis class (1 vs. 2; p = 0.001), and age (<65 vs. ${\geq}65$ years; p = 0.036) were significant predictive factors for OS. Primary disease control (p = 0.041) and ECOG status (p = 0.017) were the significant prognostic factors for IPFS. Four patients experienced radiation necrosis. Conclusion: SRS is a safe and effective local treatment for brain metastases in patients with NSCLC. Uncontrolled primary lung disease and ECOG status were significant predictors of OS and intracranial failure. SRS might be a tailored treatment option along with careful follow-up of the intracranial and primary lung disease status.

• Radiation Oncology Journal
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• 제33권2호
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• pp.89-97
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• 2015

Purpose: To evaluate the treatment results in early stage non-small cell lung cancer patients who have undergone fiducial-less CyberKnife radiosurgery (CKRS). Materials and Methods: From June 2011 to November 2013, 58 patients underwent CKRS at Asan Medical Center for stage I lung cancer. After excluding 14 patients, we retrospectively reviewed the records of the remaining 44 patients. All analyses were performed using SPSS ver. 21. Results: The median age at diagnosis was 75 years. Most patients had inoperable primary lung cancer with a poor pulmonary function test with comorbidity or old age. The clinical stage was IA in 30 patients (68.2%), IB in 14 (31.8%). The mean tumor size was 2.6 cm (range, 1.2 to 4.8 cm), and the tumor was smaller than 2 cm in 12 patients (27.3%). The radiation dose given was 48-60 Gy in 3-4 fractions. In a median follow-up of 23.1 months, local recurrence occurred in three patients (2-year local recurrence-free survival rate, 90.4%) and distant metastasis occurred in 13 patients. All patients tolerated the radiosurgery well, only two patients developing grade 3 dyspnea. The most common complications were radiation-induced fibrosis and pneumonitis. Eight patients died due to cancer progression. Conclusion: The results showed that fiducial-less CKRS shows comparable local tumor control and survival rates to those of LINAC-based SABR or CKRS with a fiducial marker. Thus, fiducial-less CKRS using Xsight lung tracking system can be effectively and safely performed for patients with medically inoperable stage I non-small cell lung cancer without any risk of procedure-related complication.

• 대한방사선치료학회지
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• 제29권2호
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• pp.9-17
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• 2017

목 적: 방사선치료에서 CT number에 의해 나타나는 조직의 묘사 및 전자밀도는 CT(Computed Tomography)기반의 전산화치료계획 정확성을 보장하는데 중요한 역할을 한다. 하지만 체내의 금속 이식물은 CT number의 정확성을 감소시킬 뿐 아니라 조직 묘사에 대한 불확실성을 나타내기 때문에 임상에서는 metal artifact를 감소시킬 수 있는 알고리즘이 개발되었다. 이에 본 연구에서는 본원에서 사용하고 있는 GE사의 SMART MAR의 CT number 정확도를 평가하고 방사선치료에서의 유용성에 대해 평가하고자 한다. 대상 및 방법: 영상평가를 위해 CIRS ED phantom을 이용하여 6개 조직의 rod를 삽입하여 동일한 체적의 ROI를 형성 후 original 영상을 획득하고 의료용 티타늄 rod를 삽입하여 non-SMART MAR 영상과 SMART MAR영상을 획득하여 CT number와 SD값을 비교하였다. Metal artifact로 인해 CT number 변화에 따른 선량변화 확인을 위해 전산화계획시스템 Epclipse를 사용하여 CIRS ED phantom CT 영상에 PTV를 형성하여 original 영상을 획득하고 편측 티타늄 삽입, 양측 티타늄 삽입 영상을 획득하여 non-SMART MAR와 SMART MAR영상에 동일한 치료계획을 수립하여 PTV가 받는 평균처방선량, HI(Homogeneity Index), CI(Conformity Index)를 비교, 분석하였다. 흡수선량 측정은 원통형 아크릴 팬텀과 0.125 cc ionchamber, electrometer를 이용하여 선량변환상수(cCy/nC)를 계산하고 CIRS phantom을 이용하여 편측, 양측 티타늄 rod를 삽입한 영상으로 non-SMART MAR와 SMART MAR 영상을 획득하여 동일한 지점에서의 흡수선량을 측정하여 전산화치료계획상의 point dose와 비교하였다. 결 과: 영상평가 결과 CT number는 non-SMART MAR영상보다 SMART MAR 영상이 original영상에 더 유사한 값이 나왔고 SD값은 SMART MAR영상에서 더 감소되었다. 선량평가 결과 평균처방선량과 HI 및 CI 값은 SMART MAR 영상보다 non-SMART MAR 영상이 original 영상에 더 근접한 결과가 나왔지만 통계적으로 유의하지 않았다. 흡수선량 측정결과 치료계획상의 point dose와 실제 흡수선량과의 차이가 non-SMART MAR의 영상에서는 각각 2.69, 3.63 %의 차이가 있었지만 SMART MAR영상에서는 0.56, 0.68 %로 감소하였다. 결 론: 금속 이식물을 삽입한 환자의 CT 영상에 SMART MAR를 적용했을 때 CT number 정확성 상승 및 SD 감소로 영상의 질이 향상되므로 종양과 정상조직의 윤곽도 생성 및 선량계산 시 유용할 것으로 사료된다.

• Applied Science and Convergence Technology
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• 제23권6호
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• pp.309-316
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• 2014

A large particle accelerator requires an ultrahigh vacuum (UHV) system of average pressure under $1{\times}10^{-7}$ Pa for mitigating the impact of beam scattering from the residual gas molecules. The surface inside the beam ducts should be controlled with an extremely low thermal outgassing rate under $1{\times}10^{-9}Pa{\cdot}m^3/(s{\cdot}m^2)$ for the sake of the insufficient pumping speed. To fulfil the requirements, the aluminum alloys were adopted as the materials of the beam ducts for large accelerator that thanks to the good features of higher thermal conductivity, non-radioactivity, non-magnetism, precise machining capability, et al. To put the aluminum into the large accelerator vacuum systems, several key technologies have been developed will be introduced. The concepts contain the precise computer numerical control (CNC) machining process for the large aluminum ducts and parts in pure alcohol and in an oil-free environment, surface cleaning with ozonized water, stringent welding process control manually or automatically to form a large sector of aluminum ducts, ex-situ baking process to reach UHV and sealed for transportation and installation, UHV pumping with the sputtering ion pumps and the non-evaporable getters (NEG), et al. The developed UHV technologies have been applied to the 3 GeV Taiwan Photon Source (TPS) and revealed good results as the expectation. The problems of leakage encountered during the assembling were most associated with the vacuum baking which result in the consequent trouble shootings and more times of baking. Then the installation of the well-sealed UHV systems is recommended.

• Radiation Oncology Journal
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• 제31권1호
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• pp.34-40
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• 2013

Purpose: To evaluate the predictive factors of radiation pneumonitis (RP) and associated changes in pulmonary function after definitive concurrent chemoradiotherapy (CCRT) in patients with non-small cell lung cancer (NSCLC). Materials and Methods: Medical records of 60 patients with NSCLC who received definitive CCRT were retrospectively reviewed. Dose volumetric (DV) parameters, clinical factors, and pulmonary function test (PFT) data were analyzed. RP was graded according to the CTCAE ver. 4.0. Percentage of lung volume that received a dose of threshold (Vdose) and mean lung dose (MLD) were analyzed for potential DV predictors. PFT changes were calculated as the difference between pre-RT and post-RT values at 3, 6, and 12 months after RT. Results: Twenty-two patients (37%) developed grade ${\geq}2$ RP. Among clinical factors, tumor location in lower lobe was associated with RP. Among the DV parameters, only MLD >15 Gy was associated with grade ${\geq}2$ RP. There were statistically significant decreases in PFT at all points compared with pre-RT values in grade ${\geq}2$ RP group. MLD was associated with forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) changes at 6 and 12 months. V10 was associated with FVC changes at 12 months. V20 and V30 were associated with FEV1 changes at 6 months and FVC changes at 12 months. Conclusion: After definitive CCRT in patients with NSCLC, MLD >15 Gy and lower lobe tumor location were predictors of grade ${\geq}2$ RP. Pulmonary functions were decreased after CCRT and the magnitude of changes was associated with DV parameters.

• 대한방사선치료학회지
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• 제29권1호
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• pp.57-68
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• 2017

목 적: 본 연구는 모양이 불규칙하고 손상위험장기(Organ At Risk, OAR)에 매우 인접한 타겟(Target)의 방사선 치료 시, 비동일평면상(Non-coplanar)의 빔(Beam)을 이용한 Fixed-field 세기변조 방사선치료(Intensity Modulated Radiation Therapy, IMRT)와 용적변조회전 방사선치료(Volumetric Modulated Arc Therapy, VMAT) 치료계획의 유용성을 평가 및 비교해 보고자 하였다. 대상 및 방법: 본원에서 True Beam STX(Varian Medical Systems, USA)를 이용하여 전체 두피(Whole Scalp), 부분적 두피(Partial Scalp), 그리고 전체 뇌실(Whole Ventricle)에 방사선 치료를 받은 환자 중 각 부위별로 2명 씩, 총 6명을 대상으로 하였다. VMAT 치료계획 시, Beamlet에 포함되는 OAR의 용적을 최소화하기 위해 Coplanar 또는 Non-coplanar 빔을 이용하였고, Fixed-field IMRT는 6명 모두 2개 이상의 카우치(Couch) 각도를 이용한 Non-coplanar IMRT(이하 ncIMRT)로 치료계획 하였다. 결 과: 양측 수정체, 양측 시신경, 시신경 교차, 그리고 뇌 줄기의 최대선량과 양측 안구와 해마의 평균선량을 측정하였고, 6명 모두 9개의 OAR 중 6개 이상에서 VMAT 치료계획이 ncIMRT보다 1.1배에서 8.2배가량 높은 선량 값을 나타내었다. 전체 두피와 부분적 두피의 치료 시, 20 Gy가 조사되는 뇌의 용적은 VMAT이 ncIMRT의 2배 이상이었고, 전체 뇌실의 치료 시에는 두 치료계획이 큰 차이를 보이지 않았다. 타겟 Coverage는 두 치료계획 모두 $PTV_{100%}=95%$를 만족시켰고, 타겟 내 최대선량과 치료 시 필요한 총 Monitor Unit(MU)은 ncIMRT가 VMAT보다 높았으며 두 치료계획 모두 임상적용을 위한 Gamma test 시행 결과, 2 mm/2 % 조건을 통과하였다. 결 론: 본 연구 결과, ncIMRT는 VMAT에 비해 치료 시 필요한 MU가 높아 치료시간과 장비의 로딩(Loading)을 증가시키므로 치료의 효율성은 다소 떨어지지만, VMAT과 비슷한 타겟 Coverage를 유지하면서, OAR의 선량은 훨씬 감소시키는 것을 알 수 있었다. 따라서 모양이 불규칙하고 OAR에 매우 인접해 있는 타겟의 방사선 치료 시에는 ncIMRT 치료계획을 고려해 볼 필요가 있다고 사료된다.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-1
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• pp.54-55
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• 2003

Radiation therapy has been used for the cancer treatment externally or internally. The external radiation therapy has been widely used, but for the lack of its selectivity it requires strong radiation dose causing the dermal irritation and radiation effect of the normal tissues or organs. So we investigate non-clinical and clinical studies of “Milican inj.”, in which chitosan is chelated with 166-Holmium, as an anticancer agent for internal radiation therapy. (omitted)