METHODS: In the study, 170 patients were to receive 4 courses of platinum/etoposide and were randomized to receive twice-daily TRT of 60 Gy/40 fractions (fx) or 45 Gy/30 fx. TRT treatment plans for those who received 1 or more fx of TRT (n = 166) were analyzed.
RESULTS: The most common treatment planning technique was 3-dimensional conformal radiation therapy (67%). The 75th percentile of the reported dose-volume parameters for the OARs were within the protocol-recommended limits for both groups. Mean doses to the esophagus of 25.5 Gy (IQR, 20.2-31.3; 60 Gy/40 fx) and 24.3 Gy (IQR, 20.3-27.5; 45 Gy/30 fx) were associated with 21% and 18% ≥ grade 3 acute esophagitis, respectively. In the 60 Gy/40 fx group, a mean dose to the lungs of 16.5 Gy (IQR, 15.8-16.9), V20 Gy of 29.5% (IQR, 28.8-30.4), and V5 Gy of 65.6% (IQR, 61.5-68.7) led to ≥ grade 3 pneumonitis in 4% of the patients. There was no ≥ grade 3 pneumonitis in the 45 Gy/30 fx group. The treatment planning techniques, the percentage change in volumes between original and redelineated OARs, planning target volumes, relative doses, and laterality were well balanced between the randomly assigned groups.
CONCLUSIONS: Considering the incidences of severe radiation-induced toxicities were within the range of other recent trials, the reported doses to the OARs appear to be safe. Treatment planning parameters were well balanced between the randomly assigned groups, supporting that the survival benefit of the twice-daily 60 Gy/40 fx TRT schedule was due to the higher dose.
方法:170例患者接受4个疗程的铂/依托泊苷,并随机接受每日两次60Gy/40分数(fx)或45Gy/30fx的TRT。分析了那些接受一个或多个fx的TRT(n=166)的TRT治疗计划。
结果:最常见的治疗计划技术是3DCRT(67%)。两组OAR报告的剂量-体积参数的第75百分位数均在方案推荐的范围内。食道平均剂量为25.5Gy(IQR:20.2-31.3)[60Gy/40fx]和24.3Gy(IQR:20.3-27.5)[45Gy/30fx]与21%和18%≥3级急性食管炎相关,分别。在60Gy/40fx组中,肺的平均剂量为16.5Gy(IQR:15.8-16.9),V20Gy为29.5%(IQR:28.8-30.4),V5Gy为65.6%(IQR:61.5-68.7)导致4%的患者≥3级肺炎。45Gy组无≥3级肺炎。治疗计划技术,原始和重新划定的OAR之间的体积变化百分比,PTV音量,相对剂量,随机分配组之间的偏侧性平衡良好。
结论:考虑到严重辐射所致毒性的发生率在其他近期试验的范围内,报告给OAR的剂量似乎是安全的。随机分配组之间的治疗计划参数平衡良好,支持每日两次60Gy/40fxTRT方案的生存益处是由于较高的剂量。