• Radiation Oncology Journal
• /
• 제6권2호
• /
• pp.283-288
• /
• 1988

초기 유방암의 치료는 근치적 절제술이 오랫동안 주된 치료방법으로써 선택되어 왔으나, 근래에는 여성의 유방을 보존하고 미용효과를 기대할 수 있는 보조적 절제술 후 근치적 방사선치료법이 개발되어 지대한 관심과 상당한 논란이 거듭되어 왔다. 이러한 논란을 해결하기 위하여 그동안 세계적으로 많은 후향성 또는 전향성 분석을 시행하여 두 치료방법사이의 치료효과를 비교하여 본 결과, 국소치료율, 재발을, 그리고 생존율에 있어서 큰 차이를 보이지 않았다. 이와 같은 치료성적의 결과를 토대로 하여 최근에는 보조적 절제술 후 근치적 방사선치료법이 여성들의 유방을 보존하고 미용효과를 향상시킬 수 있을 뿐만 아니라 국소치료율, 재발율, 생존율도 근치적 절제술의 성적과 대동소이하므로 초기 유방암의 치료에 활발히 이용되기에 이르렀다. 본원에서도 이러한 추세에 따라서 보조적 절제술 후 근치적 방사선치료를 시행한 초기 유방암 1예를 보고하면서 아울러 많은 문헌고찰과 함께 향후 치료방침을 세우고자 한다.

• 대한방사선기술학회지:방사선기술과학
• /
• 제40권1호
• /
• pp.71-78
• /
• 2017

디지털 방사선영상 시스템에서 산란선은 피검사체와 엑스선의 반응에 의해 발생하는 근원적인 현상이다. 방사선 투사영상은 일차선에 의해 형성되는 감쇠정보를 영상화 하므로 산란선은 투사영상에서 노이즈로써 작용한다. 본 연구에서는 다양한 검사조건에서 발생하는 산란선을 빔 저지체(beam stopper)를 이용하여 정량화하고 동시에 반 산란 격자의 효과를 확인하였다. 또한 산란선이 영상의 품질에 미치는 영향을 확인하기 위해 산란선에 의해 저하되는 대조도 대 잡음비를 측정하였다. 본 연구를 통해 산란선은 피검사체의 두께 및 공기층(air gap)에 지배적인 경향을 가짐을 확인하였다. 또한 산란선은 영상의 대조도를 현격히 저하시킴을 정량적으로 측정하였다. 산란선을 저감하기 위해 격자를 장착함으로써 상당량의 산란선을 저감할 수 있었으나 여전히 두꺼운 피검사체에 대해 많은 양의 산란선이 남아 있음을 확인하였다. 본 연구에서는 산란선을 정량화 하는 방법론을 제시하였으며, 향후 시스템의 최적화에 중요한 역할을 할 수 있을 것으로 기대된다.

• Radiation Oncology Journal
• /
• 제21권2호
• /
• pp.143-148
• /
• 2003

목적: 자궁경부암으로 진단을 받고 수술단독 치료만 시행 받은 후 재발암에서 방사선치료를 시행하고 생존율 및 실패양상을 알아보고자 하였다. 대상 및 방법: 1990년 1월부터 1999년 12월까지 계명대학교 동산의료원 방사선종양학과에선 초기(I, IIa) 자궁경부암으로 진단을 받고 수술 후 재발하여 방사선치료를 받은 환자 27명을 대상으로 하였다. 연령분포는 31세에서 70세로 평균 48세이며 수술 당시 병기 1기가 20명, 2기가 7명이었고 23명이 편평상피암이었고 4명은 선암이었다. 수술 후 재발까지의 기간은 2개월에서 90개월로 평균 29개월이었다. 재발부위로는 질 부위가 14명, 골반강이 9명, 복합재발이 4명이었다. 수술은 25명에서 전자궁적출술과 골반내림프절절제술을 시행하였으며 2명은 전자궁적출술만을 시행하였다. 방사선치료는 13명에서는 외부방사선치료만을 받았고 13명에서는 외부방사선치료와 질강내방사선 치료를 받았으며 1명은 질강내방사선치료만을 받았다. 방사선치료 후 추적관찰기간은 6개월에서 128개월로 중앙값 55개월이었다. 결과: 전체 환자의 5년 생존율과 5년 무병생존율은 각각 71.9$\%$, 68.2$\%$이었다. 재발부위에 따른 생존율의 차이가 통계적으로 유의하지는 않았으나 질 부위에만 재발하여 방사선치료를 받은 환자에서 가장 높은 5년 무병생존율을 나타내었다(5년 무병생존율, 질 부위에만 재발한 환자는 85.7$\%$, 질 부위를 제외한 골반부위에 재발한 환자 53.3$\%$, p=0.09). 재발시기에 따른 생존율의 차이는 보이지 않았다. 실패양상으로는 질 부위에만 재발하여 방사선치료를 받은 환자들에서 7$\%$의 국소재발만 있었고 골반강내에 재발하여 방사선치료를 받은 환자들은 국소재발이 주된 실패이었고 골반과 복벽, 복막 등에 같이 재발되었던 환자들은 방사선치료 후 원격전이가 주된 실패이었다. 방사선치료 후 3도 이상의 부작용은 없었다. 결론: 이상으로 볼 때, 초기 자궁경부암에서 수술단독치료 후 재발암에서는 방사선치료는 효과적이고 안전한 치료법이라고 생각되며 특히 수술 후 질 부위에만 재발한 경우에는 외부방사선치료와 질강내방사선치료로 좋은 생존율을 기대할 수 있겠다.

• Radiation Oncology Journal
• /
• 제35권2호
• /
• pp.163-171
• /
• 2017

Purpose: Although stereotactic ablative body radiotherapy (SABR) is widely used therapeutic technique, predictive factors of radiation pneumonitis (RP) after SABR remain undefined. We aimed to investigate the predictive factors affecting RP in patients with primary or metastatic lung tumors who received SABR. Materials and Methods: From 2012 to 2015, we reviewed 59 patients with 72 primary or metastatic lung tumors treated with SABR, and performed analyses of clinical and dosimetric variables related to symptomatic RP. SABR was delivered as 45-60 Gy in 3-4 fractions, which were over 100 Gy in BED when the ${\alpha}/{\beta}$ value was assumed to be 10. Tumor volume and other various dose volume factors were analyzed using median value as a cutoff value. RP was graded per the Common Terminology Criteria for Adverse Events v4.03. Results: At the median follow-up period of 11 months, symptomatic RP was observed in 13 lesions (12 patients, 18.1%), including grade 2 RP in 11 lesions and grade 3 in 2 lesions. Patients with planning target volume (PTV) of ${\leq}14.35mL$ had significantly lower rates of symptomatic RP when compared to others (8.6% vs. 27%; p = 0.048). Rates of symptomatic RP in patients with internal gross tumor volume (iGTV) >4.21 mL were higher than with ${\leq}4.21mL$ (29.7% vs. 6.1%; p = 0.017). Conclusions: The incidence of symptomatic RP following treatment with SABR was acceptable with grade 2 RP being observed in most patients. iGTV over 4.21 mL and PTV of over 14.35 mL were significant predictive factors related to symptomatic RP.

• Radiation Oncology Journal
• /
• 제11권1호
• /
• pp.103-108
• /
• 1993

Among the patients with rectal cancer who entered Yonsei University Hospital for management from Jan. 1980 to Dec. 1990, we selected 23 subjects who were received surgical resection of tumor in rectum, and who proved to have liver metastasis during the diagnostic work-up, at the time of the operation, or within 3 months after starting definitive treatment. With those subjects, we investigated the role of radiation therapy by comparison of the treatment results of the patients without radiation therapy (S group) with those of the patients with radiation therapy to the primary site (S+R group). The local control rates of S group and S+R group were $64{\%}$ and $89{\%}$, and 2-year survival rates were $50{\%}$ and $78{\%}$, respectively. Although there was not statistically meaningful difference, local control rate and 2-year survival rate were higher in the group with radiation therapy to primary site than that without radiation therapy. The 2-year survival rates of the case with resection of the liver and the case without it were $63.6{\%}$ and $58.3{\%}$ respectively, which was not statistically significant. Also, the 2-year survival rate of the case with sustained local control was higher than that of the case with local failure, which was statistically significant ($76.5{\%}$ and $16.7{\%}$, p<0.005). From the above results, it is thought that radiation therapy to the primary site might improve the local control rate even in the patients with liver metastasis, which seems to be correlated to the higher survival rate.

• Radiation Oncology Journal
• /
• 제1권1호
• /
• pp.61-67
• /
• 1983

Two cases of primary malignant lymphoma of the brain and six cases of secondary CNS lymphoma seen at Yonsei cancer center, radiotherapy department for recent 4 years are presented. Primary lymphomas revealed single tumor mass on corpus callosum area and secondary lymphoma were intracranial (3 cases) or leptomeningeal type (3 cases). Histology of primary lymphoma were reticulum cell sarcoma and secondary lymphomas were either diffuse histiocytic or diffuse poorly differentiated lymphocytic lymphoma. All patients showed good response to radiation. Two patients with primary CNS lymphoma and two of six secondary CNS lymphoma are alive after radiotherapy (34, 31, 26, 12 months). But the prognosis of secondary CNS lymphoma is grave, because of progressive systemic disease. Incidence, risk factors, diagnosis and therapeutic management of CNS involvement are also discussed.

• Nuclear Engineering and Technology
• /
• 제52권10호
• /
• pp.2204-2220
• /
• 2020

An open-pool type research reactor is designed and operated considering the accessibility around the pool top area to enhance the reactor utilization. The reactor structure assembly is placed at the bottom of the pool and filled with water as a primary coolant for the core cooling and radiation shielding. Most radioactive materials are generated from the fuel assemblies in the reactor core and circulated with the primary coolant. If the primary coolant goes up to the pool surface, the radiation level increases around the working area near the top of the pool. Hence, the hot water layer is designed and formed at the upper part of the pool to suppress the rising of the primary coolant to the pool surface. The temperature gradient is established from the hot water layer to the primary coolant. As this temperature gradient suppresses the circulation of the primary coolant at the upper region of the pool, the radioactive primary coolant rising up directly to the pool surface is minimized. Water mixing between these layers is reduced because the hot water layer is formed above the primary coolant with a higher temperature. The radiation level above the pool surface area is maintained as low as reasonably achievable since the radioactive materials in the primary coolant are trapped under the hot water layer. The key to maintaining the stable hot water layer and keeping the radiation level low on the pool surface is to have a stable flow of the primary coolant. In the research reactor with a downward core flow, the primary coolant is dumped into the reactor pool and goes to the reactor core through the flow guide structure. Flow fields of the primary coolant at the lower region of the reactor pool are largely affected by the dumped primary coolant. Simple, circular, and duct type discharge headers are designed to control the flow fields and make the primary coolant flow stable in the reactor pool. In this research, flow fields of the primary coolant and hot water layer are numerically simulated in the reactor pool. The heat transfer rate, temperature, and velocity fields are taken into consideration to determine the formation of the stable hot water layer and primary coolant flow. The bulk Richardson number is used to evaluate the stability of the flow field. A duct type discharge header is finally chosen to dump the primary coolant into the reactor pool. The bulk Richardson number should be higher than 2.7 and the temperature of the hot water layer should be 1 ℃ higher than the temperature of the primary coolant to maintain the stability of the stratified thermal layer.

• Radiation Oncology Journal
• /
• 제38권1호
• /
• pp.18-25
• /
• 2020

Purpose: This study was aim to evaluate the patterns of failure according to radiotherapy (RT) target volume for cervical lymph nodes in metastases of unknown primary origin in head and neck region (HNMUO). Materials and Methods: Sixty-two patients with HNMUO between 1998 and 2016 were retrospectively reviewed. We analyzed the clinical outcomes and primary site failure depending on the radiation target volume. The target volume was classified according to whether the potential head and neck mucosal sites were included and whether the neck node was treated involved side only or bilaterally. Results: Potential mucosal site RT (mucosal RT) was done to 23 patients and 39 patients did not receive mucosal RT. Mucosal RT showed no significant effect on overall survival (OS) and locoregional recurrence (LRR). The location of primary site failure encountered during follow-up period was found to be unpredictable and 75% of patients with recurrence received successful salvage therapies. No significant differences in OS and LRR were found between patients treated to unilateral (n = 35) and bilateral neck irradiation (n = 21). Treatment of both necks resulted in significantly higher mucositis. Conclusions: We found no advantages in OS and LRR of patients with HNMUO when mucosal sites and bilateral neck node were included in the radiation target volume.

• Radiation Oncology Journal
• /
• 제23권2호
• /
• pp.111-115
• /
• 2005

질에서 발생하는 원발성 악성 흑색종은 희귀한 질환으로, 높은 국소 재발률과 조기 전이로 인하여 매우 나쁜 예후를 보인다. 전통적으로 높은 국소 재발율과 낮은 생존율의 개선을 위하여 질 절제술, 골반 내용 제거술 및 서혜부 임파절제술과 같은 근치적 수술을 시행하였으나, 재발률 및 생존율의 개선에 실패하였다. 그러나 최근 광범위 국소 제거술 및 소분할조사법으로 근치적 수술과 유사하거나 향상된 생존율이 보고되고 있다. 또한 병소의 크기가 3 cm 이하인 경우는 일차적 방사선치료만으로도 수술적 절제술과 유사한 생존이 가능하다고 하였다. 저자들은 질에서 발생한 원발성 악성 흑색종에 방사선치료를 시행한 2예를 경험하였기에 문헌 고찰과 함께 보고하고자 한다.

• Radiation Oncology Journal
• /
• 제3권1호
• /
• pp.65-68
• /
• 1985

Primary lymphoid tumors of orbit are rare. Sometimes they pose difficulty in differentiating malignant non-Hodgkin's lymphoma of the orbit from benign lymphoid hyperplasia or pseudotumor of the orbit by growth characteristics and histologic examination of a biopsy specimen. Consequently, systemic work-up for staging of the disease before the initiation of treatment is essential. All lymphoid tumors of the orbit are radiosensitive and the response to radiotherapy is rapid and complete. Radiation dose for permanent control varies from 2,400 to 4,500rads in $2.5\~4$ weeks depending on extent and location of the disease. A case of localized lymphoma of the orbit was treated with radiotherapy. For the following 15 months, the patient was clinically free of disease without any evidence of side effects of radiation treatment.