Final report of a prospective randomized study on thoracic radiotherapy target volumes for limited-stage small cell lung cancer / 中华放射肿瘤学杂志

ABSTRACT

Objective In view of the controversy over radiotherapy target volume for patients with limited-stage small cell lung cancer ( SCLC), a prospective randomized controlled trial was conducted to compare the impact of different radiotherapy target volumes on prognosis. Methods After 2 cycles of EP chemotherapy,patients without progressive disease were randomly assigned to receive thoracic radiotherapy (TRT) to either the post-or pre-chemotherapy primary tumour extent as study arm or control. Involved field radiotherapy (IFRT) to the entire metastatic lymph node regions was applied for both arms. TRT consisted of 45 Gy/30Fx/19 d administered concurrently with cycle 3 chemotherapy. Prophylactic cranial irradiation was administered to patients achieved complete or partial remission. Kaplan-Meier method was used for survival analysis. Results Between June 2002 and December 2017,159 and 150 patients were randomly assigned to study arm and control respectively. The 1-,2-,and 5-year local/regional control rates were 79. 4%,61. 5% and 60. 1% respectively in the study arm versus 79. 8%,66. 5%,and 57. 3% in the control arm (P=0. 73). The median OS time was 22. 1 months in the study arm (95%CI,18. 2-26. 0 months) and 26. 9 months (95%CI,23. 5-30. 3 months) in the control arm,the 1-,3-,5-,and 7-year OS rates were 81. 1%,31. 6%, 23. 9% and 22. 2% respectively in the study arm versus 85. 3%,36. 6%,26. 1% and 20. 0% in the control arm (P=0. 51).Grade 2-3 acute esophagitis was developed in 32. 9% and 43. 2% of patients respectively in study arm and control arm (P=0. 01),while grade 2-3 pulmonary fibrosis was observed in 2. 0% and 10. 9% of patients ( P= 0. 01 ) respectively. Conclusions For patients with limited-stage SCLC who received induction chemotherapy,thoracic radiotherapy can be limited to post-chemotherapy tumour extent and IFRT can be routinely applied.