质子碳离子笔形束扫描技术治疗Ⅰ期非小细胞肺癌的初步结果

Preliminary clinical results after pencil beam scanning particle radiotherapy for stage Ⅰ non-small cell lung cancer

目的在国内首次报道采用质子碳离子射线治疗Ⅰ期非小细胞肺癌（NSCLC）的近期疗效和不良反应。方法2014年8月至2015年12月，共收治10例病理证实的Ⅰ期NSCLC患者。使用IONTRIS设备笔形束扫描技术，通过可以调节能量的点扫描、实现对靶区更加适形的目的，2～4个射野给予质子和碳离子放疗。根据肿瘤部位给予不同分割方式照射，4例周围型接受50～70GyE／10次放疗，3例中间型60～64GyE／15～16次，3例中央型66～72GyE／22～24次。结果中位随访时间为18．1（11．9～28．1）个月，最后一次随访时患者均存活。10例患者局部控制率100％，其中6例患者完全缓解，3例部分缓解，1例疾病稳定；2例放疗后随访中出现远处转移。放疗开始3个月内，无3级及以上放疗相关急性不良反应发生。随访期内未观察到2级及以上的晚期不良反应。放疗后1和3—5个月肺功能（最大通气量、第1秒通气量及CO弥散量）与放疗前相比略有上升，差异无统计学意义（P〉0．05）。结论对Ⅰ期非小细胞肺癌患者，质子碳离子笔形束扫描技术治疗短期随访结果安全、有效。

Objective To evaluate the safety and efficacy of proton and carbon-ion radiotherapy （RT） for stage I non-small cell lung cancer （NSCLC） with pencil beam scanning technique. Methods From August 2014 to December 2015, 10 patients with stage I NSCLC who were inoperable or refused surgery were treated by proton ＋/- carbon-ion RT. Primary lesions were irradiated using 2 -4 portals with 45-degree beams. A total dose of 50 - 70 GyE/IO fractions, 60 - 64 GyE/15-16 fractions, and 66-72 GyE/22- 24 fractions were administered to patients based on tumor location （4 peripheral, 3 middle, and 3 central lesions, respectively）. Results At the last follow-up in December 2016 with the median follow-up of 18.1 （ 11.9 - 28. 1 ） months, local control was found in all patients per CT or PET/CT scanning（6 complete response, 3 partial response, and 1 stable disease）. However, 2 patients with local control （ 1 partial response and 1 stable disease） experienced a distant failure at 8.7 and 24.9 months after RT, respectively. There was no RT-related Grade 3 -5 toxicity in all patients. Grade 2 toxicities were only found in 2 patients （acute skin reaction and leueopenia, respectively）. At 1, 3 -5 months after RT, the pulmonary function tests showed a slightly increase in FVC, FEV1 and DLCO-sb compared with those before RT without statistical significance （ P 〉 0.05 ）. Conclusions The particle RT using pencil beam scanning technique was safe, and yielded encouraging outcome for patients with stage I NSCLC who were inoperable or refused surgery. Further follow-up and prospective clinical studies are warranted in the future.