서울의대 / 김병혁, 김학재*
Purpose: In the treatment of concurrent chemoradiotherapy (CCRT) in limited-stage small cell lung cancer, the optimal once-daily radiotherapy (RT) dose/fractionation remain unclear although it is the most frequently used. Therefore, this study aimed to compare the treatment outcomes and toxicities of modest dose RT (≤ 54 Gy) with those of standard dose RT (> 54 Gy) and investigate the benefit of the high dose based on patient factors.
Materials and methods: Since 2004, our institution has gradually increased the thoracic RT dose. Among the 225 patients who underwent CCRT, 84 patients (37.3%) received > 54 Gy. Because the patients treated with RT > 54 Gy were not randomly assigned, propensity score matching (PSM) was performed.
Results: The proportion of patients treated with > 54 Gy increased over time (p=0.014). Multivariate analysis revealed that the overall tumor stage and dose > 54 Gy (hazard ratio, 0.65; p=0.029) were independent prognostic factors for overall survival (OS). PSM confirmed that thoracic RT doses of > 54 Gy showed significantly improved progression-free survival (3-year, 42.7% vs. 24.0%; p < 0.001) and OS (3-year, 56.2% vs. 38.5%; p=0.003). Sensitivity analysis also showed that 60 Gy resulted in better survival than 54 Gy. However, in patients with underlying lung disease, OS benefit from > 54 Gy was not observed but considerable rates of severe pulmonary toxicities were observed (p=0.001).
Conclusion: Our analysis supports that the 60 Gy RT dose should be considered in the once-daily regimen of CCRT for limited-stage small cell lung cancer without underlying lung disease, but RT dose > 54 Gy did not seem to benefit for patients with chronic obstructive pulmonary disease or interstitial lung disease. Further study is needed to validate these results.
A. 기저 폐질환이 없는 제한병기 소세포폐암 환자들에서 54Gy 이상의 흉부 방사선조사 시 생존율 향상 효과가 있음.
B, C. 폐쇄성 폐질환(B) 과 간질성 폐질환(C)의 기저 질환이 있는 환자들에서는 54Gy 를 기준으로 방사선량에 따른 생존률 차이가 없음.
Byoung Hyuck Kim 1 2, Joo-Hyun Chung 3, Jaeman Son 3, Suzy Kim 1, Hong-Gyun Wu 2 3 4 5, Hak Jae Kim 2 3 4 5
1Department of Radiation Oncology, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, Korea.
2Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.
3Department of Radiation Oncology, Seoul National University Hospital, Seoul, Korea.
4Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Korea.
5Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.