中老年Ⅲ期食管鳞癌患者根治性调强放疗的预后和剂量研究

Dosimetric and clinical outcomes with intensity-modulated radiation therapy for middle-aged and elderly patients with stage Ⅲ esophageal squamous cell cancer

目的评价中老年Ⅲ期（T3N1M0，T4NanyM0）食管鳞状细胞癌接受根治性调强放疗（IMRT）的治疗结果、毒性反应和剂量学优势。方法回顾性分析2009年3月至2015年10月，接受根治性调强放疗的Ⅲ期食管鳞癌患者28例，年龄45～83岁。其中6例接受了同步化疗，8例接受了同步靶向治疗。食管肿瘤中位平均放疗剂量为67．1Gy。通过分析剂量-体积直方图评价放疗靶区和危及器官剂量学参数。采用Kaplan—Meier法计算总生存率（OS）、无进展生存率（PFS）和局部区域控制率（LRC）。根据美国放射治疗肿瘤协作组（RTOG）标准评价毒性反应。结果放疗计划靶区（PTV）的平均适形指数和均匀指数分别为0．82和0．92，表明靶区覆盖度很好。全组3年OS、PFS和LRC分别为48．0％、31．2％和62．0％。≥3级急性放射性食管炎仅2例（2／34，5．9％），≥2级急性放射性肺炎仅3例（3／34，8．8％）。结论中老年Ⅲ期食管鳞癌接受根治性IMRT可实现良好的靶区覆盖度继而获得更高的局部控制率和总生存率，同时急性毒性反应可以接受。

Objective To assess the dosimetric benefit, prognosis and toxicity of intensity modulated radiation therapy （IMRT） for stage Ⅲ esophageal squamous cell cancer. Methods This was a retrospective analysis of 28 patients, aged between 45 and 83 years, with stage Ⅲ esophageal squamous cell cancer who had received radical IMRT. Of these patients, six received concurrent chemotherapy and eight received targeted therapy. The median radiotherapy dose was 67. 1 Gy. Dosimetric parameters for the target volume and critical normal structures were evaluated by dose volume histogram. The Kaplan-Meier method was used to calculate overall survival （OS） ,progress free survival （PFS） and locoregional control （LRC）. Results The mean conformity index （CI） and homogeneity index （HI） scores of the planning target volume （PTV） were 0.82 and 0.92, respectively,indlcating very good coverage of the target volume. Three-year OS, PFS, and LRC were 48.0 %, 31.2 %, and 62.0 %, respectively. Acute toxicities were mild,only two patients developed acute esophagitis （grade ≥ 3）, and three bad acute pneumonitis （grade ≥ 2）. Conclusions IMRT can provide excellent dose conformity and achieve favorable I.RC and survival with only mild toxicities in patients with stage Ⅲ esophageal squamous cancer.