广泛期SCLC化疗后IMRT的疗效分析

目的 回顾研究广泛期SCLC化疗后IMRT的疗效及预后。方法 回顾分析2007—2012年在本院放疗科接受化疗+IMRT的130例初治广泛期SCLC患者,化疗方案以EP、CE方案为主,放疗剂量32 Gy~63 Gy,35例患者进行了PCI。Kaplan-Meier法计算生存率,Logrank法单因素预后分析,Cox模型多因素预后分析。结果 随访率96.1%。全组治疗毒性轻微,≥2级血液学毒性及放射性食管炎发生率分别为22.3%、12.2%,≥2级RP发生率7.7%。放疗后达CR、PR、SD、PD者分别占4.6%、72.3%、6.2%、13.1%,疗效未能评价5例,客观有效率76.9%。中位生存期18个月(4~66个月),1、2年OS率分别为72.3% 、38.3%。30例(23.1%)患者放疗后发生局部区域失败,83例(63.8%)发生远处失败。26例放疗计划可恢复的局部区域失败患者中,22例单纯照射野内失败,2例单纯野外失败,2例野内野外同时失败。单因素分析中年龄、LDH水平、放疗剂量、PCI是影响预后因素(P=0.014、0.049、0.043、0.003),多因素分析中放疗剂量、PCI是影响预后因素(P=0.021、0.007)。初诊无脑转移患者PCI明显改善生存(HR=2.318,95%CI为1.388~3.871;P=0.003)并降低累积脑转移率(18.4%:37.2%,P=0.038)。胸部放疗EQD₂剂量达54 Gy可改善OS (HR=1.615,95%CI为1.016~2.567;P=0.043),并有改善PFS趋势(HR=1.49,95%CI为0.965~2.299,P=0.072)。结论 化疗有效的广泛期SCLC行胸部放疗可提高LC率及OS率,适当提高胸部剂量可改善患者预后。PCI可显著改善OS并降低脑转移发生率。

Clinical outcomes of extensive stage small cell lung cancer patients treated with intensive modified radiotherapy

Objective To determine the effect and the patterns of failure in extensive small cell lung cancer (SCLC) patients treated with thoracic intensive modified radiotherapy (IMRT).Methods A retrospective review was conducted on 130 extensive stage SCLC patients received thoracic IMRT from January 2007 to December 2012.Most patients received initial chemotherapy with carboplatin plus etoposide or chemotherapy with cisplatin plus etoposide and 35 patients received PCI.The median thoracic radiation dose was 56 Gy (32-67 Gy) with 1.8-2.3 Gy per fractions.The Kaplan-Meirer and log-rank test,Cox regression were used for survival analysis and to identify prognostic factors.Results The median follow-up duration was 37 months (range,4-66) in all patients and follow-up rate was 96.1％ (5 patients lost).The acute toxicity was relatively mild.Hematological toxicity of ≥ grade 2 occurred in 22.3％ and acute esophagitis of ≥ Grade 2 occurred in 12.2％ of the patients.7.7％ of patients developed ≥ Grade 2 radiation pneumonitis after radiation.The rates of CR,PR,SD,PD after thoracic radiation were 4.6％,72.3％,6.2％,13.1％,respectively.response imformation of 5 patients lost and objective response rate was 76.9％.The median survival time was 18 months (range,4-66) and 1-year,2-year overall survival rate were 72.3％,38.3％,respectively.Eighty-three patients had distant metastatic and 30 patients had local-regional failure (LRF).There were 26 patients experienced LRF with electronically archived treatment plans available for analysis,22 patients only experienced in-filed failures,2 patients only developed out-filed failures and 2 patients developed simultaneous in-field and out-filed failures.By univariate analysis,age,LDH level,thoracic radiation dose and PCI were statistically significant prognostic factor for OS (P=0.014,0.049,0.043,0.003).Thoracic radiation dose and PCI show statistically significant difference in multivariate analysis (P=0.021,0.007).PCI reduces cumulative brain metastases rates (18.4％ vs.37.2％,P=0.038) and prolongs overall survival (HR=2.318,95％ CI=1.388-3.871,P=0.003) Patients received thoracic radiation EQD2 ≥ 54 Gy improved overal survival (HR=1.615,95％ CI=1.016-2.567,P=0.043) and tended to improved progression free survival (HR=1.49,95％ CI=0.965-2.299,P=0.072).Conclusions Definitive thoracic radiation by IMRT in ED-SCLC responsive to chemotherapy may improve local-regional control and overall survival.Relatively high BED radiation seems to be favorable.Prophylactic cranial irradiation can notably prolong survival and reduce brain metastases.