Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
J Radiat Res. 2013 Mar 1;54(2):337-43. doi: 10.1093/jrr/rrs084. Epub 2012 Sep 14.
The purpose of this study is to evaluate the dose-volume metrics under different heterogeneity corrections and the factors associated with local recurrence (LR) after stereotactic body radiation therapy (SBRT) for non-small-cell lung cancer (NSCLC). Eighty-three patients who underwent SBRT for pathologically proven stage I NSCLC were reviewed retrospectively. The prescribed dose was 48 Gy in four fractions at the isocenter (IC) under heterogeneity correction with the Batho power law (BPL). The clinical plans were recalculated with Eclipse (Varian) for the same monitor units under the BPL and anisotropic analytical algorithm (AAA) and with no heterogeneity correction (NC). The dose at the IC, dose that covers 95% of the volume (D95), minimum dose (Min), and mean dose (Mean) of the planning target volume (PTV) were compared under each algorithm and between patients with local lesion control (LC) and LR. The IC doses under NC were significantly lower than those under the BPL and AAA. Under the BPL, the mean PTV D95, Min and Mean were 8.0, 9.4 and 7.4% higher than those under the AAA, and 9.6, 9.2 and 4.6% higher than those under NC, respectively. Under the AAA, all dose-volumetric parameters were significantly lower in T1a patients than in those with T1b and T2a. With a median follow-up of 35.9 months, LR occurred in 18 patients. Between the LC and LR groups, no significant differences were observed for any of the metrics. Even after stratification according to T-stage, no significant difference was observed between LC and LR.
本研究旨在评估不同异质性校正下的剂量-体积学指标，以及与立体定向体放射治疗（SBRT）治疗非小细胞肺癌（NSCLC）后局部复发（LR）相关的因素。回顾性分析了 83 例经病理证实为 I 期 NSCLC 行 SBRT 的患者。在异质性校正下，采用 Batho 幂律（BPL），在等中心点（IC）处给予 48Gy，4 次分割。根据相同的监测单位，在 Eclipse（瓦里安）中重新计算临床计划，分别采用 BPL 和各向异性分析算法（AAA）和无异质性校正（NC）。在每个算法下，比较 IC 剂量、覆盖 95%体积的剂量（D95）、最小剂量（Min）和计划靶区（PTV）的平均剂量（Mean），并比较局部病变控制（LC）和 LR 患者之间的差异。NC 下的 IC 剂量明显低于 BPL 和 AAA 下的 IC 剂量。在 BPL 下，PTV 的平均 D95、Min 和 Mean 分别比 AAA 高 8.0%、9.4%和 7.4%，比 NC 高 9.6%、9.2%和 4.6%。在 AAA 下，T1a 患者的所有剂量-体积参数均明显低于 T1b 和 T2a 患者。中位随访 35.9 个月后，18 例患者发生 LR。在 LC 和 LR 组之间，任何指标均无显著差异。即使根据 T 分期进行分层，LC 和 LR 之间也没有观察到显著差异。
