复发、转移子宫颈癌调强放疗和三维适形放疗的比较

 目的　比较调强放疗（IMRT）和三维适形放疗（3DCRT）治疗复发、转移子宫颈癌的疗效、剂量学及毒副作用。方法　回顾性分析治疗后复发转移子宫颈癌62例，其中IMRT组29例，3DCRT组33例，均行直线加速器6 MV X线放疗，单次剂量1.8～2.2 Gy,每周5次，共18～33次，处方剂量40～60 Gy，中位剂量52.8 Gy。同时对IMRT组的患者设计行3DCRT，给予相同的处方剂量，比较危及器官（OAR）受照射剂量。结果　IMRT组膀胱和小肠的最高剂量分别为（4642.71±805.53）cGy和（4240.36±572.51）cGy，低于3DCRT组的（5057.53±1998.03） cGy和（5953.99±1180.81）cGy（P＜0.05)；IMRT计划中PTV的最高剂量（5245.68±365.26）cGy高于3DCRT的最高剂量（4801.27±346.25）cGy，差异具有统计学意义（P＜0.05）。IMRT组1、2、3年生存率分别为65.5 %(19／29)、42.1 %(8／19)、25.0 %（2／8），中位生存时间为19个月，28例死亡病例中，21例死于肿瘤进展，7例死于远处转移；3DCRT组：1、2、3年生存率分别为60.6 %（20／33）、35.0 %（7／20）、14.3 %(1／7)，中位生存时间为17个月，32例死亡病例中，24例死于肿瘤进展，8例死于远处转移。IMRT组和3DCRT组比较，1、2、3年生存率差异无统计学意义（均P＞0.05）。IMRT组的不良反应的发生率明显低于3DCRT组，尤其是Ⅰ级和Ⅱ级，IMRT组为24.1 %（7／29），3DCRT组为33.5 %（11／33）。结论　IMRI对于复发转移子宫颈癌疗效较3DCRT更好，可以在提高肿瘤剂量的同时减少正常组织的受照体积和剂量，减少不良反应的发生。

Comparison of intensity-modulated radiation therapy and 3-dimentional conformal radiotherapy plansfor cervical carcinoma with recurrence and metastasis

Objective To compare the treatment effects, dosimetry, and toxicitles to organs at risk of intensity-modulated radiation therapy （IMRT） and 3-dimentional conformal radiotherapy （3DCRT） plans for cervical carcinoma patients with recurrence and metastasis. Methods 62 cervical carcinoma patients with recurrence and metastasis were analyzed retrospectively, and divided into two groups including intensitymodulated radiation therapy group （n=29） and 3-dimentional conformal radiotherapy group （n=32）. Patients were performed with 6 MV-X ray. The regimen was 1.8-2.2 Gy/f, 1 f/d, 18-33 times in total. Prescribed dose was 40-60 Gy and median dose was 52.8 Gy. At the same time for the IMRT group 29 cases were performed with 3DCRT, which was designed using the same prescribed dose to compare radiation dose distributed in organs at risk （OAR）. Results The maximum dose of the two plans showed that bladder and small intestine in IMRT plans were lower than that in 3DCRT （P〈0.05）, showing the IMRT＇s protective advantage. The maximum dose of PTV in IMRT plans were significantly higher than 3DCRT （P〈0.05）. In the group of IMRT plans, the overall 1-,2-,and 3-year survival rates were 65.5 %（19/29）, 42.1%（8/19）, and 25.0 %（2/8）, respectively, the median survival time was 19 months, of 28 deaths, 21 patients died of tumor progression, 7 patients died of distant metastases. In the group of 3DCRT plans, the overall 1-, 2-, and 3-year survival rates were 60.6 %（20/33）, 35.0 %（7/20）, and 14.3 %（1/7）,respectively, the median survival time was 17 months, of 32 deaths, 24 patients died of tumor progression, 8 patients died of distant metastasis. There were no significant differences in overall 1-, 2-, and 3-year survival rates between the two groups （P〉0.05）. The incidence rate of toxicity in the IMRT plans was significantly lower than that in the 3DCRT plans, especially for patients with I level and II level. Conclusion The treatment effects of the IMRT plans are better than the 3DCRT plans for cervical carcinoma patients with recurrence and metastasis. IMRT plans can improve radiation dose in tumors and reduce the dose distributed in normal issue and reduce the incidence of the side effects.