局部晚期宫颈癌自适应放疗剂量学及生存分析与毒性反应评价

目的： 对比研究自适应调强放疗（adaptive radiation therapy,ART）或单程调强放疗两种不同体外放疗模式治疗局部晚期宫颈癌的剂量学改变及初步临床疗效与毒性反应，探索局部晚期宫颈癌外照射合理模式。方法：收集我院2010年5月至2015年5月间112例行根治性放化疗的局部晚期宫颈癌（FIGO：IIB～IVA期）病例，根据患者外照射模式不同分为两组。A组：单程放疗组，共62例患者，外照射全程未更改放疗计划；B组：自适应放疗组，共50例患者，按首程放疗计划（plan1）照射完成15次（27~30Gy）后重新制定放疗计划（plan2）并且按新计划完成后续治疗。两组患者外照射结束后均接受高剂量率腔内近距离后装治疗。放疗期间两组患者均行顺铂单药同步化疗。比较B组两程计划肿瘤体积和危及器官剂量学改变，并对两组患者进行随访，评价比较患者急慢性毒性反应发生情况及进行生存分析。 结果：B组中plan2与plan1相比，肿瘤平均体积从（107.67±32.02）cm3，退缩到（63.21±25.78）cm3，平均缩小（41.12±13.02）cm3，平均退缩率为（35.48±5.16）%，P＜0.05。直肠平均剂量［Dmean （34.18±0.99）Gy vs.（ 37.09±0.74 ）Gy，P=0.011］、最大剂量［Dmax (50.15±0.69) Gy vs (52.05±0.77) Gy，P=0.003］、1cm3体积受照剂量［(D1cc 48.21±2.02 )Gy vs (49.90±4.19 )Gy，P=0.045］；膀胱平均剂量［Dmean(34.46±0.50）Gy vs (35.36±0.54) Gy，P=0.023］、最大剂量［Dmax（52.53±1.19） Gy vs (54.88±0.89) Gy，P=0.028］、1cm3体积受照剂量［D 1cc（50.60±3.28） Gy vs (52.61±4.64) Gy，P=0.021］，以上剂量指标差异均有统计学意义。A组和B组急性腹泻发生率差异有统计学意义（48.39% vs. 30%，P=0.046），其它急性及慢性毒性反应发生率差异均无统计学意义。A组和B组患者中位随访时间分别为25个月和27个月，3年总生存率分别为 90.9%和95.2%（P＞0.05），3年无进展生存率分别为80.4%和93.3%（P＞0.05）。结论：局部晚期宫颈癌外照射过程中肿瘤体积可显著性缩小，采用 ART技术与单程放疗相比3年OS和PFS无明显差异，但ART技术可以降低直肠、膀胱的受照剂量，降低患者治疗期间急性腹泻的发生率。

Dosimetric Change,Survival and Toxicities Study for Locally Advanced Cervix Carcinoma Treated with Adaptive Radiotherapy (ART) during External Beam Radiotherapy (EBRT)

Objective:To evaluate dosimetric change in organs at risk (OARs),clinical effect and toxicities of ART for locally advanced cervical carcinoma by comparing single-course intensity modulated radiotherapy during EBRT.Methods:A total of 112 locally advanced (FIGO Stage ⅡB-ⅣA) cervical cancer cases receiving concurrent radiochemotherapy in our hospital from May 2010 to May 2015 were enrolled in this study.Patients were divided into two groups according to their EBRT mode,including group A accepted single-course radiotherapy (n =62) and group B accepted adaptive radiotherapy(ART) (n =50).Patients in Group B received 15 fractions EBRT using the first course plan(plan1),then received 10 subsequent fractions radiation using redesigned adaptive plan (Plan2).Intensity modulated radiation therapy (IMRT) was adopted for external radiation in both groups.IMRT synchronized dosage compensation 3D-intracvitary brachytherapy(3D-ICBT) with high dosage rate was adopted after EBRT in both groups.In addition,concurrent chemotherapy with weekly cisplatin was administered to patients in both groups.For the first stage,radiotherapy regimens of two plans in Group B were compared to determine volume change of tumor and dosimetric change of OARs.For the second stage,patients were followed up to compare survival conditions and occurrences of toxicity between the two groups.Results:Average tumor volume was decreased from (107.67 ± 32.02) cm3 to (63.21 ± 25.78) cm3 after 15 fractions of EBRT with an average reduction rate of (35.48 ± 5.16) ％ (P ＜ 0.05)in Group B.Dose-volume histogram (DVH) showed that the values of Dmax,Dmean,D1 cc of rectum and bladder in plan 2 were significantly decreased(P ＜ 0.05) in comparison to those in plan1.The incidence of acute diarrhea in group A was significantly higher than that in Group B (48.39％ vs.30％,P =0.046),while no significant differences was found of the incidence of other acute and chronic toxicities between these two groups.The 3-year overall survival(OS) was 90.9％ and 95.2％ in group A and B,respectively (P ＞ 0.05).The 3-year progress free survival(PFS) was 80.4％ and 93.2％ in group A and v group B,respectively (P ＞ 0.05).Conclusion:The tumor volume decreases obviously during EBRT process for the locally advanced cervical carcinoma.Both therapy modes of EBRT can bring favorable therapeutic effects.Implementation of ART during EBRT might reduce irradiated dosages in rectum and bladder as well as reduce the occurrence of acute diarrhea of patients.