Nakamura Masaki, Nishikawa Ryo, Mayahara Hiroshi, Uezono Haruka, Harada Aya, Hashimoto Naoki, Nishimura Hideki
Department of Radiation Oncology, Kobe Minimally Invasive Cancer Center, Kobe, Hyogo, Japan.
Division of Radiation Oncology, National Cancer Center Hospital East, Kashiwa-shi, Chiba, Japan.
J Thorac Dis. 2019 Jan;11(1):214-221. doi: 10.21037/jtd.2018.12.115.
The treatment efficacy after CyberKnife stereotactic body radiotherapy (SBRT) have not been adequately addressed. The purpose of this study was to investigate pattern of recurrence according to irradiation field after CyberKnife SBRT for early-stage non-small cell lung cancer (NSCLC).
This retrospective study included patients with peripheral cT1/2N0M0 NSCLC that was treated with SBRT using a CyberKnife between May 2013 and March 2016 at single institute and followed up by more than two imaging examinations. Both operable and inoperable patients were included. Overall survival (OS) and progression-free survival (PFS) curves were estimated using the Kaplan-Meier method with 95% confidence intervals (CI). Cumulative incidence curves of recurrence were calculated and compared using the Gray's test.
Total 71 patients were included and analyzed in this study. The median follow-up period for surviving patients was 34 months (range, 7-64 months). The 2-year OS and PFS rate were 93% (95% CI: 83-97%) and 77% (95% CI: 65-86%), respectively. The 2-year cumulative incidence rate of infield recurrence and out-of-field recurrence were 6% (95% CI: 2-14%) and 17% (95% CI: 9-27%), respectively. Gross tumor volume (GTV) ≥9 mL and diagnosis-to-treatment interval (DTI) ≥90 days were significantly associated with infield recurrence (P<0.001 and P=0.007), and epidermal growth factor receptor (EGFR) mutation was significantly associated with out-of-field recurrence (P=0.014).
Treatment efficacy after CyberKnife SBRT for peripheral early-stage NSCLC was identical to previous conventional linac-based SBRT reports. With short follow-up period, it was found that GTV and DTI were the significant predictive factor of infield recurrence, and EGFR mutation was the significant predictive factor of out-of-field recurrence.
射波刀立体定向体部放射治疗（SBRT）后的治疗效果尚未得到充分研究。本研究的目的是调查射波刀SBRT治疗早期非小细胞肺癌（NSCLC）后根据照射野的复发模式。
本回顾性研究纳入了2013年5月至2016年3月在单一机构接受射波刀SBRT治疗的外周cT1/2N0M0 NSCLC患者，并进行了两次以上的影像学检查随访。纳入了可手术和不可手术的患者。采用Kaplan-Meier法估计总生存（OS）和无进展生存（PFS）曲线，并给出95%置信区间（CI）。使用Gray检验计算并比较复发的累积发病率曲线。
本研究共纳入并分析了71例患者。存活患者的中位随访期为34个月（范围7 - 64个月）。2年OS率和PFS率分别为93%（95%CI：83 - 97%）和77%（95%CI：65 - 86%）。野内复发和野外复发的2年累积发病率分别为6%（95%CI：2 - 14%）和17%（95%CI：9 - 27%）。肿瘤总体积（GTV）≥9 mL和诊断至治疗间隔（DTI）≥90天与野内复发显著相关（P<0.001和P = 0.007），表皮生长因子受体（EGFR）突变与野外复发显著相关（P = 0.014）。
射波刀SBRT治疗外周早期NSCLC的疗效与以往基于传统直线加速器的SBRT报告相同。随访期较短，发现GTV和DTI是野内复发的重要预测因素，EGFR突变是野外复发的重要预测因素。
