局限期小细胞肺癌不同剂量分割模式放疗的疗效分析

The effect of dose fractionation on overall survival in patients with limited-stage small cell lung cancer

目的 比较不同剂最分割模式放疗对局限期小细胞肺癌生存的影响.方法 回顾分析本院2001-2007年收治的177例局限期小细胞肺癌患者资料.入组条件为病理学证实、局限期且接受了根治性放化疗的患者.根据剂量分割模式将患者分为常规分割组（1.8～2.0 Gy/次,1次/d,63例）、超分割组（1.4 Gy/次,2次/d,79例）和大分割组（2.5 Gy/次,1次/d,35例）.对3个组的总生存率、无进展生存率和治疗失败模式进行统计分析.结果 随访率为96.6%,随访满2、5年者分别为153、92例.全组2、5年总生存率分别为43.4%、23.5%,中位生存期为22.4个月.常规分割组、超分割组、大分割组的2年总生存率和无进展生存率分别为31%、46%、59%（x2=7.94,P=0.019）和20%、31%、40%（x2=4.86,P=0.088）,两两比较发现2年总生存率大分割组优于常规分割组（x2=7.81,P=0.005）,超分割组介于两组之间但差别均无统计学意义（x2=2.31,P=0.128;x2=2.95,P=0.086）.毒副反应以大分割组最轻,局部进展与远处转移分布3个组相似.结论 大分割放疗局限期小细胞肺癌显示了一定生存优势,有必要前瞻性临床研究验证其临床价值.

Objective To study the effect of different dose fractionation on overall survival in patients with limited-stage small cell lung cancer （LS-SCLC）. Methods LS-SCLC patients treated with radical combined chemotherapy and radiotherapy （RT） between January 2001 and Dec 2007 were analyzed retrospectively. According to the dose fractionation schemes, patients were divided into three groups：conventional fractionated RT （1. 8 -2.0 Gy,once daily）, hyperfractionated RT （1.4 Gy, twice daily） and hypofractionated RT （2. 5 Gy,once daily）. Overall survival, disease free survival and pattern of failures of the three groups were compared. A total of 177 patients were enrolled, including 63 patients in conventional fractionated RT group, 79 in hyperfractionated RT group and 35 in hypofractionated RT group. Results The overall follow-up rate was 96. 6%. The patient numbers with follow-up of more than 2 and 5 years were 153 and 92, respectively. The median survival time of the entire group was 22. 4 months, and the 2-and 5-year survival rates were 43.4% and 23. 5%, respectively. The 2-year survival rates for three groups were 31%, 46% and 59% （x2 =7.94,P=0.019）, respectively. The 2-year disease free survival for three groups were 20%, 31% and 40% （ x2 = 4. 86, P = 0. 088 ）, respectively. In the pairwise comparisons,patients in hypofractionated RT group have better survival than those in conventional fractionated RT group （ x2 = 7. 81, P = 0. 005 ）, the effect of hyperfractionated RT group lies between the hypo-and the conventional fractionated RT groups, but no significant differences were detected （ x2 = 2. 31, P = 0. 128; x2 = 2. 95, P =0. 086）. The mildest side effect was found in the hypofractionated RT group. No statistically significant differences were found in the patterns of first failure. Conclusion The hypofractionated RT scheme showed potential survival benefits for patients with LS-SCLC and should be considered in the setting of randomized clinical trials.