锥形束CT引导下VMAT-SBRT治疗非小细胞肺癌肺部寡转移靶区边界和临床疗效及毒副反应

Target area margin, clinical efficacy and toxicity of cone-beam CT VMAT-SBRT in treatment of non-small cell lung cancer with lung oligometastasis

目的 探讨锥形束CT引导下VMAT-SBRT治疗非小细胞肺癌肺部寡转移的靶区边界和临床疗效及毒副反应。方法 收集2016年1月至2018年1月温州医科大学附属第一医院放疗中心VMAT-SBRT治疗的NSCLC肺部寡转移患者40例,56个寡转移灶,4DCT定位,55 Gy/5次,VMAT-SBRT隔天照射;每次治疗前CBCT获取校准前摆位误差,在线校正后再次CBCT获取校正后误差,SPSS 19.0统计分析校正前后误差,由扩边公式Mptv=2.5Σ+0.7δ计算临床靶区到计划靶区的外放边界。治疗结束后1、3、6、12、24个月和36个月复查增强CT,用实体瘤评价标准RECIST1.1评价疗效,用Kaplan-Meier法进行局部控制及生存分析,用RTOG的放射损伤标准评定急慢性毒副反应。结果 CBCT校正前后X、Y、Z方向靶区外扩边界,校正前:0.51 cm、0.65 cm、0.57 cm;校正后:0.24 cm、0.38 cm、0.27 cm。随访6~42个月,CR 22.5%、PR 60.0%、SD 10.0%和PD 7.5%,CR+PR 82.5%;1、2、3年的LC率为95%、84%和73%,1年、2年、3年的OS率为85%、68%、45%。放疗后急慢性毒副反应为放射性肺炎、放射性食管炎、放射性纤维化,均为0~2级,无3级及以上反应。结论 CBCT引导下靶区外扩边界明显缩小,VMAT-SBRT治疗NSCLC肺部寡转移毒副反应小,局部控制率和生存率高,疗效显著,是一种安全可靠的治疗方式。

Objective To investigate the target area margin, clinical efficacy and toxicity of cone-beam CT VMAT-SBRT in the treatment of non-small cell lung cancer with lung oligometastasis. Methods Forty patients with NSCLC with lung oligometastasis treated with VMAT-SBRT in Radiotherapy Centre, the 1st Affiliated Hospital of Wenzhou Medical University from January 2016 to January 2018 were selected. There were 56 oligometastases. The 4DCT localization was conducted with 55 Gy/5 times, and VMAT-SBRT irradiation was conducted every other day. CBCT was used to obtain the pre-calibration setup error before every treatment and the post-calibration error after online calibration. SPSS 19.0 was used to analyze the error before and after calibration. The expansion formula Mptv=2.5Σ+0.7δ was applied to calculate the margin from clinical target area to planned target area. Reexaminations of enhanced CT were conducted at 1,3,6,12,24 and 36 months after the end of treatment.The efficacy evaluation standard of solid tumor RECIST1.1 was used to evaluate the efficacy.The Kaplan-Meier method was used for local control and survival analysis.The RTOG radiation injury criteria were used to assess acute and chronic toxicity. Results The margin of target area in the X,Y, and Z directions were expanded before and after CBCT calibration.The margin before calibration were 0.51cm, 0.65 cm and 0.57 cm.The margin after calibration were 0.24 cm, 0.38 cm and 0.27 cm. At follow-up 6 to 42months,CR was 22.5%, PR was 60.0%,SD was 10.0%,PD was 7.5%, and CR+PR was 82.5%. The LC rates at 1,2 and 3years were 95%, 84% and 73%. The OS rates at 1, 2 and 3 years were 85%, 68% and 45%. The acute and chronic toxic and side effects after radiotherapy were radiation pneumonia,radiation esophagitis, and radiofibrosis,all of which were of grade 0-2.There were no events of grade 3 and above. Conclusion CBCT significantly reduces the margin of target area. VMAT-SBRT has small side effects, high local control rate and survival rate, and significant efficacy in the treatment of NSCLC with lung oligometastasis. It is a safe and reliable treatment method.