局部晚期宫颈癌CT图像引导下适形调强后程推量的临床研究

Clinical investigation on CT image-guided IMRT late-course boost for patients with local advanced cervical cancer

目的:观察利用三维适形调强技术(Intensity modulated radiotherapy,IMRT)、采用5Gy×5f分割模式对于局部晚期宫颈癌患者盆腔外照射后残留病灶局部推量的治疗效果及并发症发生。方法:33例局部晚期宫颈癌患者在完成盆腔外照射及同期DDP化疗后,行CT模拟定位扫描,定位前及每次治疗前均进行膀胱灌注以控制膀胱的充盈程度,勾画子宫颈、宫旁及阴道侵犯区域以及2cm阴道组织、子宫体下段2/3为CTV-boost,CTV-boost加5、15mm为PTV-boost,设计并执行7野三维适形调强计划,处方剂量为5Gy/f×5f,2f/w。结果:1年总生存率、无病生存率、盆腔控制率分别为82%、76%、79%,其中15mm PTV边界组的1年盆腔控制率为90%。结论:对于不能进行腔内后装治疗的部分局部晚期宫颈癌患者,采用5Gy×5f分割模式的三维适形调强技术进行后程推量可达到根治效果,1年内未见严重直肠、膀胱并发症出现,远期疗效及并发症正在进一步观察中。

Objective：To investigate the effects and late radiation morbidity of intensity modulated radiotherapy（IMRT） late course boost with fractionation schedule of 5Gy/f × 5f for patients with local advanced cervical cancer.Methods：Finishing the whole pelvic irradiation,33 patients with local advanced cervical cancer received CT simulation scan.CTV-boost and organs at risk were contoured.CTV-boost included whole cervix,cervical tumor and extension to the parametria and vagina,2cm of upper vagina,lower 2/3 of corpora uteri.PTV-boost margin was 5 or 15mm around CTV-boost.IMRT late course boost plan with 7 fields was designed,optimized and delivered.Radiation schedule was 5Gy per fraction and 2 fraction per week with 25Gy of total boost dose.Bladder filling was controlled by bladder perfusion before CT simulation scan and each delivering.Results：One year overall survival,disease-free survival and pelvic tumor control was 82%,80%,84% respectively.The pelvic tumor control was 90% in group with PTV-15mm margin.Conclusion：Intensity modulated radiotherapy（IMRT） late course boost with fractionation schedule of 5Gy/f × 5f can get radical effects for patients with local advanced cervical cancer who can not receive or refuse the intracavitary brachytherapy.No severe radiation reaction appeared during one year follow up and longer effect and morbidity needs further investigation.