방사선 폐렴의 임상적 특징

이재호(Jae Ho Lee),현인규(In Gyu Hyun),최동철(Dong Chul Choi),유철규(Chul Gyu Yu),송재훈(Jae Hoon Song),정기석(Ki Suck Jung),김영환(Young Whan Kim),한성구(Sung Ku Han),심영수(Young Soo Shim),김건열(Keun Yeol Kim),한용철(Yong Chul Han 대한내과학회 1991 대한내과학회지 Vol.40 No.3

Radiation pneumonitis is one of the most important early complication of radiation therapy. In order to examine whether or not the increasing in patients suffering from concurrent COPD and Lung Ca, and to study clinical features of radiation pneumonitis, the writers conducted a retrospective study on 60 patients with proven lung cancer who underwent radiation therapy during the period from 1985 to 1988 and had their PFT performed before the radiation and obtained the following results; 1) Non productive cough was the most frequent clinical symptom of radiation pneumonitis and dyspnea, whitish sputum, chest tightness, mild fever was also present. The clinical symptom was not related to radiation dose, initial time of pneumonitis, PFT, age but was more serious in the patients with FEV1/FVC more than 70%. 2) Radiation pneumonitis occurred most frequently between the period of 4 weeks and 12 weeks and onset time of radiation pneumonitis was not related to the radiation dose, PFT, age, 3) Chest X-ray showed alveolar, alveolar-interstitial mixed, interstitial pattern, fibrosis confined to radiation field and changed with time. 4) There was no significant difference between FEV1, FVC, FEV1/FVC and incidence of radiation pneumonitis but in patents with FEV1/FVC more then 70%, there was significantly higher incidence of radiation pneumonitis. 5) The incidence of radiation pneumonitis was increased as radiation dose was increased.

Factors predicting radiation pneumonitis in locally advanced non-small cell lung cancer

Myungsoo Kim,Jihae Lee,Boram Ha,Rena Lee,Kyung-Ja Lee,Hyun Suk Suh 대한방사선종양학회 2011 Radiation Oncology Journal Vol.29 No.3

Purpose: Thoracic radiotherapy is a major treatment modality of stage Ⅲ non-small cell lung cancer. The normal lung tissue is sensitive to radiation and radiation pneumonitis is the most important dose-limiting complication of thoracic radiation therapy. This study was performed to identify the clinical and dosimetric parameters related to the risk of radiation pneumonitis after definitive radiotherapy in stage Ⅲ non-small cell cancer patients. Materials and Methods: The medical records were reviewed for 49 patients who completed definitive radiation therapy for locally advanced non-small cell lung cancer from August 2000 to February 2010. Radiation therapy was delivered with the daily dose of 1.8 Gy to 2.0 Gy and the total radiation dose ranged from 50.0 Gy to 70.2 Gy (median, 61.2 Gy). Elective nodal irradiation was delivered at a dose of 45.0 Gy to 50.0 Gy. Seven patients (14.3%) were treated with radiation therapy alone and forty two patients (85.7%) were treated with chemotherapy either sequentially or concurrently. Results: Twenty-five cases (51.0%) out of 49 cases experienced radiation pneumonitis. According to the radiation pneumonitis grade, 10 (20.4%) were grade 1, 9 (18.4%) were grade 2, 4 (8.2%) were grade 3, and 2 (4.1%) were grade 4. In the univariate analyses, no clinical factors including age, sex, performance status, smoking history, underlying lung disease, tumor location, total radiation dose and chemotherapy were associated with grade ≥2 radiation pneumonitis. In the subgroup analysis of the chemotherapy group, concurrent rather than sequential chemotherapy was significantly related to grade ≥2 radiation pneumonitis comparing sequential chemotherapy. In the univariate analysis with dosimetric factors, mean lung dose (MLD), V20, V30, V40, MLDipsi, V20ipsi, V30ipsi, and V40ipsi were associated with grade ≥2 radiation pneumonitis. In addition, multivariate analysis showed that MLD and V30 were independent predicting factors for grade ≥2 radiation pneumonitis. Conclusion: Concurrent chemotherapy, MLD and V30 were statistically signifi cant predictors of grade ≥2 radiation pneumonitis in patients with stage Ⅲ non-small cell lung cancer undergoing definitive radiotherapy. The cutoff values for MLD and V30 were 16 Gy and 18%, respectively.

Factors predicting radiation pneumonitis in locally advanced non-small cell lung cancer

Kim, Myung-Soo,Lee, Ji-Hae,Ha, Bo-Ram,Lee, Re-Na,Lee, Kyung-Ja,Suh, Hyun-Suk The Korean Society for Radiation Oncology 2011 Radiation Oncology Journal Vol.29 No.3

Purpose: Thoracic radiotherapy is a major treatment modality of stage III non-small cell lung cancer. The normal lung tissue is sensitive to radiation and radiation pneumonitis is the most important dose-limiting complication of thoracic radiation therapy. This study was performed to identify the clinical and dosimetric parameters related to the risk of radiation pneumonitis after definitive radiotherapy in stage III non-small cell cancer patients. Materials and Methods: The medical records were reviewed for 49 patients who completed definitive radiation therapy for locally advanced non-small cell lung cancer from August 2000 to February 2010. Radiation therapy was delivered with the daily dose of 1.8 Gy to 2.0 Gy and the total radiation dose ranged from 50.0 Gy to 70.2 Gy (median, 61.2 Gy). Elective nodal irradiation was delivered at a dose of 45.0 Gy to 50.0 Gy. Seven patients (14.3%) were treated with radiation therapy alone and forty two patients (85.7%) were treated with chemotherapy either sequentially or concurrently. Results: Twenty-five cases (51.0%) out of 49 cases experienced radiation pneumonitis. According to the radiation pneumonitis grade, 10 (20.4%) were grade 1, 9 (18.4%) were grade 2, 4 (8.2%) were grade 3, and 2 (4.1%) were grade 4. In the univariate analyses, no clinical factors including age, sex, performance status, smoking history, underlying lung disease, tumor location, total radiation dose and chemotherapy were associated with grade ${\geq}2$ radiation pneumonitis. In the subgroup analysis of the chemotherapy group, concurrent rather than sequential chemotherapy was significantly related to grade ${\geq}2$ radiation pneumonitis comparing sequential chemotherapy. In the univariate analysis with dosimetric factors, mean lung dose (MLD), $V_{20}$, $V_{30}$, $V_{40}$, MLDipsi, $V_{20}$ipsi, $V_{30}$ipsi, and $V_{40}$ipsi were associated with grade ${\geq}2$ radiation pneumonitis. In addition, multivariate analysis showed that MLD and V30 were independent predicting factors for grade ${\geq}2$ radiation pneumonitis. Conclusion: Concurrent chemotherapy, MLD and $V_{30}$ were statistically significant predictors of grade ${\geq}2$ radiation pneumonitis in patients with stage III non-small cell lung cancer undergoing definitive radiotherapy. The cutoff values for MLD and $V_{30}$ were 16 Gy and 18%, respectively.

Factors predicting radiation pneumonitis in locally advanced non-small cell lung cancer

김명수,이지혜,하보람,이레나,이경자,서현숙 대한방사선종양학회 2011 Radiation Oncology Journal Vol.29 No.3

Purpose: Thoracic radiotherapy is a major treatment modality of stage III non-small cell lung cancer. The normal lung tissue is sensitive to radiation and radiation pneumonitis is the most important dose-limiting complication of thoracic radiation therapy. This study was performed to identify the clinical and dosimetric parameters related to the risk of radiation pneumonitis after defi nitive radiotherapy in stage III non-small cell cancer patients. Materials and Methods: The medical records were reviewed for 49 patients who completed defi nitive radiation therapy for locally advanced non-small cell lung cancer from August 2000 to February 2010. Radiation therapy was delivered with the daily dose of 1.8 Gy to 2.0 Gy and the total radiation dose ranged from 50.0 Gy to 70.2 Gy (median, 61.2 Gy). Elective nodal irradiation was delivered at a dose of 45.0 Gy to 50.0 Gy. Seven patients (14.3%) were treated with radiation therapy alone and forty two patients (85.7%) were treated with chemotherapy either sequentially or concurrently. Results: Twenty-fi ve cases (51.0%) out of 49 cases experienced radiation pneumonitis. According to the radiation pneumonitis grade, 10 (20.4%) were grade 1, 9 (18.4%) were grade 2, 4 (8.2%) were grade 3, and 2 (4.1%) were grade 4. In the univariate analyses, no clinical factors including age, sex, performance status, smoking history, underlying lung disease, tumor location,total radiation dose and chemotherapy were associated with grade ≥2 radiation pneumonitis. In the subgroup analysis of the chemotherapy group, concurrent rather than sequential chemotherapy was signifi cantly related to grade ≥2 radiation pneumonitis comparing sequential chemotherapy. In the univariate analysis with dosimetric factors, mean lung dose (MLD), V20, V30, V40, MLDipsi,V20ipsi, V30ipsi, and V40ipsi were associated with grade ≥2 radiation pneumonitis. In addition, multivariate analysis showed that MLD and V30 were independent predicting factors for grade ≥2 radiation pneumonitis. Conclusion: Concurrent chemotherapy, MLD and V30 were statistically signifi cant predictors of grade ≥2 radiation pneumonitis in patients with stage III non-small cell lung cancer undergoing defi nitive radiotherapy. The cutoff values for MLD and V30 were 16 Gy and 18%, respectively.

방사선폐렴의 발생과 촉진요인에 관한 고찰

서현숙(Hyu Suk Suh),이정식(Chung Sik Rhee) 대한방사선종양학회 1987 Radiation Oncology Journal Vol.5 No.2

With the introduction of X-rays of higher energy that have higher penetrability, it has become possible to treat the deep-seated tumor with increased local control rate. But at the same time it has incrased the damage to the deep seated organs, especially to the lung which is known to be the less radiotolerable tissue in the body. This study analyses the 66 patients who were exposed to the irradiation of the lung, and examines the development of radiation pneumonitis and its related factors. The results of the study are summarized as follows: 1, The 66 patients were consisted of 40 cases of lung cancer, 15 cases of breast cancer and 11 cases of mediastinal tumors. There were 37 males and 29 females with the male to female ratio 1.3: 1. A male to female ratio in the lung cancer was 3: 1. 2. Among 66 patients, 26 patients (39%) developed the radiographical changes of acute radiation pneumonitis and 13 out of 26 patients (50%)showed the clinical features of acute radiation pneumonitis. 3. The onest of acute radiation pneumonitis ranged from 10 days to 6 months after the completion of radiotherapy. 4. There was a statistically significant close relationship between the development of radiation pneumonitis and the radiation dose. 5. As the irradiated lung volume increased, the development of radiation pneumonitis increased. But the statistical significance was not strong. 6. The increased incidence of radiation pneumonitis was observed when the chemotherapy was given before or concomittantly with radiotherapy. 7 There was no significant correlation between the development of radiation pneumonitis and the age, smoking and the presence of underlying lung disease.

폐종양 환자에서 방사선치료에 의한 폐손상

정수미(Su Mi Chung),최일봉(Ihl Bohng Choi),강기문(Ki Mun Kang),김인아(In Ah Kim),신경섭(Kyung Sub Shinn) 대한방사선종양학회 1993 Radiation Oncology Journal Vol.11 No.2

Purpose: A retrospective analysis was performed to evaluate the incidence of radiation induced lung damage after the radiation therapy for the patients with carcinoma of the lung. Method and Materials: Sixty-six patients with lung cancer (squamous cell carcinoma 27, adenocarcinoma 14, large cell carcinoma 2, small cell carcinoma 13, unknown 10) were treated with definitive, postoperative or palliative radiation therapy with or without chemotherapy between July 1987 and December 1991. There were 50 males and 16 females with median age of 63 years (range: 33~80 years). Total lung doses ranged from 500 to 6,660 cGy (median 3960 cGy) given in 2 to 38 fractions (median 20) over a range or 2 to 150 days (median in days) using 6 MV or 15 MV linear accelerator. To represent different fractionation schedules of equivalent biological effect, the estimated single dose (ED) model, ED=D․N-0.377․T-0.058 was used in which D was the lung dose in cGy, N was the number of fractions, and T was the overall treatment time in days. The range of ED was 370 to 1357. The endpoint was a visible increase in lung density within the irradiated volume on chest X-ray as observed independently by three diagnostic radiologists. Patients were grouped according to ED, treatment duration, treatment modality and age, and the percent incidence of pulmonary damage for each group was determined. Result: In 40 of 66 patients, radiation induced change was seen on chest radiographs between 11 days and 314 days after initiation of radiation therapy. The incidence of radiation pneumonitis was increased according to increased ED, which was statistically significant (p=0.001). Roentgenographic changes consistent with radiation pneumonitis were seen in 100% of patients receiving radiotherapy after lobectomy or pneumonectomy, which was not statistically significant. In 32 patients who also received chemotherapy, there was no difference in the incidence of radiation induced change between the group with radiation alone and the group with radiation and chemotherapy, among the sequence of chemotherapy No correlation was seen between incidence of radiation pneumonitis and age or sex. Conclusions: The occurrence of radiation pneumonitis varies. The incidence of radiation pneumonitis depends on radiation total dose, nature of fractionation, duration of therapy, and modifying factors such as lobectomy or pneumonectomy.

유효체적 방법과 임상분석을 통한 방사선에 의한 정상 폐조직의 부작용 확률에 관한 연구

안승도(Seung Do Ahn),최은경(Eun Kyung Choi),이병용(Byong Yong Yi),장혜숙(Hyesook Chang) 대한방사선종양학회 1997 Radiation Oncology Journal Vol.15 No.3

목 적 : 방사선에 대한 정상 폐조직의 부작용에 관한 확률은 폐암의 방사선 치료에 있어서 중요한 지표가 됨에도 불구하고 잘 알려져 있지 않다. 더구나 표적 부위와는 달리 정상 폐조직의 방사선량 분포는 매우 불균일하므로, 대표 선량값을 찾아 내는 것조차 어렵다. 본 연구에서는 Dose Volume Histogram(DVH)과 유효체적방법(Effective Volume Method)을 통하여 정상 폐조직의 선량을 정량화하고 정상 폐조직 부작용 확률(Normal Tissue Complication Probability, NTCP)을 구하여 임상결과와 비교하므로서 이 방법이 치료결과를 예측할 수 있는 주요 지표로서 가능할 수 있는지에 대하여 살펴 보고자 하였다. 대 상 및 방 법 : 1993년 8월부터 1994년 12월까지 비세포성 폐암으로 방사선과 복합항암약물요법을 병행하여 치료받은 환자 중에서 36명을 무작위 추출하여, DVH 분석을 통한 정상 폐조직의 NTCP를 구하였다. 36명의 환자는 Mitomycin C, Vinblastine, Cisplatin을 사용한 2회의 복합항암약물요법과 동시에 다분할 방사선치료(120cGy/fx, bid) 를 6480cGy 까지 병행 치료하였다. 각 환자의 치료전 CT scan을 사용하여 우측폐, 좌측폐 그리고 전 체폐 각각의 DVH를 구하였다. Kutcher 등의 Effective Volume Method로 Nonuniform Histogram을 Uniform Histogram으로 변환시켰고, TD50은 Emami 등의 자료에 의거하여, Lyman 공식을 이용하여 NTCP를 구하였다. 방사선 폐렴의 Grade는 SWOG의 Toxicity Criteria에 따랐다. 결 과 : 대상환자 36명중 6명이 Grade I, 2명이 Grade II의 방사선 폐렴이 발생하였다. 부작용이 발생한 환자군의 NTCP와 발생하지 않은 환자군의 NTCP는 전체폐를 대상으로 28.4와 23.4, 병소 부위의 폐를 대상으로 66.0과 26.4로 통계적으로 유의할 만한 차이를 보였으나 치료 전후에 시행한 폐기능 검사 소견에서는 두 군 사이에서 통계학적으로 유의한 차이를 찾지 못하였다. 결 론 : 부작용이 있는 군과 부작용이 없는 군의 NTCP는 통계적인 유의한 차이가 있었으며 NTCP와 임상적인 부작용 확률은 정량적으로 일치하였다. 그러나 NTCP는 순수하게 방사선의 효과만을 고려하고 있으나 본 연구에서는 항암약물요법을 병용하였다는 것과 다분할(Hyperfractionation) 방사선 치료에 의한 방사선 생물학적 변화에 대한 고려가 필요할 것으로 생각된다. 본 연구결과 유효체적 방법을 이용한 NTCP는 향후 입체조형 치료에서의 선량증가(Dose escalation) 가능성에 대한 부작용 예측 지표로 활용할 수 있을 것으로 생각된다. Purpose:In radiation therapy, NTCP is very important indicator of selecting the optimal treatment plan. In our study, we tried to find out usefullness of NTCP in lung cancer by comparng the incidence of radiation pneumonitis with NTCP. Methods and Materials:From August 1993 to December 1994, thirty six patients with locally advanced non-small cell lung cancer were treated by concurrent chemoradiation therapy. Total dose of radiation therapy was 6480cGy (120cGy, bid) and chemotherapeutic agents were mitomycin C, vinblastine, cisplatin (2 cycles, 4 weeks interval). We evaluated the development of radiatio n pneumonitis by CT scan, chest x-ray and clinical symptoms. We used grading system of South Western Oncology Group (SWOG) for radiation pneumonitis. Dose Volume Histograms (DVH) were analyzed for ipsilateral and whole lung. Non uniform DVH was translated to uniform DVH by effective volume method. With these data, we calculated NTCP for ipsilateral and whole lung. Finally we compared the clinical results to NTCP. Results:Eight of thrity six patients developed radiation pneumonitis. Of these 8 patients, 6 had grade I severity and 2 had grade II. The average NTCP value of the patients who showed radiation pneumonitis was significantly higher than that of the patients without pneumonitis (66% vs. 26.4%). But the results of pulmonary function test was not correlated with NTCP. Conclusion:NTCP of lung is very good indicator for selecting rival treatment planning in lung cancer. According to the results of NTCP, it may be possible to adjust target volume and optimize target dose. In the near future, we are going to analyze the effect of hyperfractionation and concurrent chemotherapy in addition to NTCP.

Radiation Induced Lung Injury: Prediction, Assessment and Management

Giridhar, Prashanth,Mallick, Supriya,Rath, Goura Kishore,Julka, Pramod Kumar Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.7

Radiation induced lung injury has long been considered a treatment limiting factor for patients requiring thoracic radiation. This radiation induced lung injury happens early as well as late. Radiation induced lung injury can occur in two phases viz. early (< 6 months) when it is called radiation pneumonitis and late (>6 months) when it is called radiation induced lung fibrosis. There are multiple factors that can be patient, disease or treatment related that predict the incidence and severity of radiation pneumonitis. Radiation induced damage to the type I pneumocytes is the triggering factor to initiate such reactions. Over the years, radiation therapy has witnessed a paradigm shift in radiation planning and delivery and successfully reduced the incidence of lung injury. Radiation pneumonitis is usually a diagnosis of exclusion. Steroids, ACE inhibitors and pentoxyphylline constitute the cornerstone of therapy. Radiation induced lung fibrosis is another challenging aspect. The pathophysiology of radiation fibrosis includes continuing inflammation and microvascular changes due to pro-angiogenic and profibrogenic stimuli resembling those in adult bronchiectasis. General supportive management, mobilization of airway secretions, anti-inflammatory therapy and management of acute exacerbations remains the treatment option. Radiation induced lung injury is an inevitable accompaniment of thoracic radiation.

The Measurements of Plasma Cytokines in Radiation-induced Pneumonitis in Lung Cancer Patients

허원주(Won Joo Hur),윤선민(Seon Min Youn),이형식(Hyung Sik Lee),양광모(Kwang Mo Yang),신건호(Geun Ho Sin),손춘희(Choon Hee Son),한진영(Jin Yeong Han),이기남(Ki Nam Lee),정민호(Min Ho Jeong) 대한방사선종양학회 2000 Radiation Oncology Journal Vol.18 No.4

목 적 :폐암으로 확진되어 근치적 방사선 치료를 받은 환자에서 방사선폐렴이 발생할 수 있는 위험군을 사전에 예측해 보고자 혈장내 TGF-β1, TNF-α, IL-6의 농도를 측정하여 폐렴 발생과의 상관관계를 분석하고자 하였다. 재료 및 방법: 1998년 5월부터 1999년 7월까지 폐암으로 확진되어 근치적 방사선 치료를 받은 17명의 환자(비소세포암 11명, 소세포암 6명)을 대상으로 하였다. 방사선 치료는 주 5회 매일 1.8 Gy씩 실시하였고 비소세포암과 소세포암에서 각각 평균 60 Gy와 54 Gy를 조사하였다. 모든 환자에서 방사선치료 전, 방사선치료 중 주 1회, 치료 후 추적관찰로 내원시마다 혈액을 채취하여 혈장 TGF-β1, TNF-α 및 IL-6의 양을 ELISA법으로 측정하였다. 모든 환자에서 단순흉부촬영(치료중 주1회, 치료 후 추적관찰 시마다 촬영) 및 방사선 폐렴과 연관된 증세를 관찰하여 방사선 폐렴의 징후가 발견되면 즉시 고해상도 컴퓨터 단층 촬영(HRCT)를 촬영하여 방사선 폐렴 발생여부를 확진하고자 하였다. 결 과: 17명의 환자 중 13명에서 방사선 폐렴과 연관된 증세가 발현되었고 단순 흉부 촬영과 고해상도 컴퓨터 단층 촬영에서 이를 확인할 수 있었다. 방사선 폐렴이 발생한 환자에서 측정한 TGF-β1의 경우 특징적인 수치 변화를 보여 치료 전 평균값은 38.45 ng/ml로 방사선 폐렴이 발생하지 않은 군에 비해 상승되어 나타났고(22.77 ng/ml) 방사선치료 중 13.66 ng/ml의 평균값을 보인 후 다시 점진적으로 상승하여 치료 2∼4주 후까지 평균 60.63 ng/ml로 상승되어 유지되었고 이 수치는 폐렴이 발생하지 않은 군과 비교할 때(12.77 ng/ml) 통계적으로 의미가 있었다(p Purpose :To investigate whether changes in plasma concentrations of transforming growth factor- β1 (TGF-β1), tumor necrosis factor- alpha (TNF-α) and interleukin- 6 (IL- 6) could be used to identify the development of radiation- induced pneumonitis in the lung cancer patients. Methods and Materials : Seventeen patients with lung cancer (11 NSCLC, 6 SCLC) were enrolled in a prospective study designed to evaluate clinical and molecular biologic correlation of radiation- induced pneumonitis. The study began in May 1998 and completed in July 1999. All patients were treated with radiotherapy with curative intent : 1.8 Gy per day, 5 fractions per week. Serial measurements of plasma TGF-β1, TNF-α and IL- 6 were obtained in all patients before, weekly during radiotherapy and at each follow- up visits after completion of treatment. These measurements were quantified using enzyme linked immunosorbent assay (ELISA). All patients were evaluated for signs and symptoms of pneumonitis at each follow- up visit after completion of radiotherapy. High resolution CT (HRCT) scans were obtained when signs and symptoms of pneumonitis were developed after completion of radiotherapy. Results :Thirteen patients eventually developed signs and symptoms of clinical pneumonitis while four patients did not. TGF-β1 levels were elevated in all 13 patients with pneumonitis, which showed characteristic pattern of elevation (38.45 ng/ml at pretreatment, 13.66 ng/ml during radiotherapy, then 60.63 ng/ml at 2- 4 weeks after completion of radiotherapy). The levels of TNF-α and IL- 6 were also elevated in the group of patients who developed pneumonitis but the pattern was not characteristic. Conclusions :Changes in plasma TGFβ- 1 levels before, during and after radiotherapy appears to be a useful means by which to identify patients at risk for the development of symptomatic pneumonitis. Other cytokines like TNF- α and IL- 6 shows no meaningful changes in association with radiation pneumonitis.

X-선 조사로 생긴 흰쥐 폐장 상해의 형태학적 변화

김진희 대한방사선종양학회 1999 Radiation Oncology Journal Vol.17 No.3

목 적 : 방사선조사 후 발생하는 폐손상을 형태학적 측면에서 평가하고 captopril의 방사선조사 후 폐손상의 경감효과가 있는지를 확인하고 captopril의 방사선에 의한 폐손상의 영향에서 TNF-α와 TGF-β의 변화을 알아보고자 하였다. 재료 및 방법 : Sprague-Dawley 종 수컷 흰쥐 30마리를 골라 방사선조사만 한 군, 방사선조사 후 captopril을 투여한 군으로 나누어 실험하였다. 방사선조사는 10 Gy, 20 Gy, 30 Gy 를 우측 폐에 조사하였다. 방사선 단독 조사군은 방사선조사 후 각각 12 시간, 11주 후에 도살하고 방사선조사 후 captopril을 투여한 군(captopril 500 mg/L를 증류수에 타서 먹임)은 11주(fibrotic period) 후에 도살하여 광학현미경과 전자현미경으로 관찰하였다. 결 과 : 방사선조사 후 12 시간내의 실험군의 폐는 부분적으로 폐실질의 허탈과 경화가 방사선조사량이 많아질수록 그 정도와 범위가 증가하였다. 방사선조사 후 11주에는 방사선 단독 조사군에서 폐섬유화의 정도와 범위가 방사선조사량이 많아질수록 증가하였고 captopril을 함께 사용한 군에서 방사선조사 단독군에 비해 폐섬유화의 경감효과가 현저하였다. 방사선 단독군에서는 방사선량이 많아질수록 비만세포의 수는 급격히 증가하였으며 captopril을 사용한 군이 사용하지 않은 군과 비교하여 비만세포 수의 증가 정도는 현저히 낮았고 교원질 침착의 정도도 현저히 감소되었다. TNF-α, TGF-β는 방사선조사 직후(12 시간) 군에서는 방사선량이 증가함에 따라 그 발현이 증가하였으나 방사선조사 후 11주군에서는 TGF-β는 방사선량이 많아짐에 따라 그 발현이 증가하였으며 captopril 투여군에서는 그 발현이 다소 감소하였다. Captopril을 사용한 군에서는 교원질의 양은 증가하였으나 방사선 단독군에 비해 교원질의 양이 적었고 혈관주위 비후의 정도와, 모세혈관의 변화정도, mast cell의 수와 탈과립, 섬유모세포의 수도 적었다. 결 론 : 방사선조사후 방사선 폐렴에서 captopril의 영향은 방사선에 의한 비만세포의 출현을 억제시키고 교원질의 침착을 감소시킴으로써 방사선에 의한 섬유화를 예방할 것으로 생각된다. TNF-α와 TGF-β의 발현은 방사선조사 후 초기에 증가하며 TGF-β는 방사선조사 후 만성기에 방사선량이 많아질수록 발현이 증가하는 것으로 판단되었다. 본 연구 결과는 captopril이 방사선조사 후 발생하는 폐손상을 감소시키는 기전을 밝히는 향후 연구에 중요한 자료가 될 것으로 생각된다. Purpose : To assess the histomorphologic changes in the rat lu ng injury induced by radiation, to determine whether captopril reduces the rat lung injury and to evaluate change in TNF -α and TGF - β in rat lung damage by radiation and captopril Methods and material : Right lungs in male Sprague -Dawley rats were divided i rradiation alone (10, 20, 30 Gy) or radiation (same dose with radiation alone group) with captopril (500 mg/L). Radiation alone group were sacrificed at twelve hours and eleven weeks after radiation and radiation with captopril group (captopril group) were sacrificed at eleven weeks after radiation with captopril. We examined the light microscope and electron microscopic features in the groups. Results : In radiation alone group, there were patch parenchymal collapse and consolidation at twelve hours after radiation. The increase of radiation dose shows more prominent the severity and broader the affected areas. Eleven weeks after radiation, the severity and areas of fibrosis had increased in proportion to radiation dose given in the radiation alone group. There was notable decrease of lung fibrosis in captopril group than in radiation alone group. The number of mast cells rapidly increased with increase of radiation dose in radiation alone group and the degree of increase of mast cell number and severity of collagen accumulation more decreased in captopril group than in radiation alone group. In radiation alone group, expression of TNF - α and TGF -β increased according to increase of radiation dose at twelve hours after radiation in both group. At eleven weeks after radiation, expression of TGF-β increased according to increase of radiation dose in radiation group but somewhat decreased in captopril group. In the captopril group the collagen deposition increased but less dense than those of radiation alone group. The severity of perivascular thickening, capillary change, the number and degranulation of mast cells more decreased in the captopril group than in the radiation alone group. Conclusion : It is concluded that the effect of captopril in the rat lungs afte r radiation was considered to be due to its effect on inhibition of mast cells and reduction of collagen deposition, and captopril may be protect in lung damage after radiation. We observed expression of TNF -α and TGF -β increased at the early phase after radiation and expression of TGF -β increased in proportion to increase of radiation dose at the chronic phase after radiation. This results will contribute to future investigation in reduction mechanism of capt opril in lung damage after radiation