宫颈癌放射治疗剂量对局部控制率与毒副反应的分析

Analysis of local control rate and toxicity of radiotherapy dose of cervical cancer

目的明确放疗剂量对宫颈鳞癌患者的局部控制率与毒副反应的影响,探索宫颈癌患者能否在高剂量中获益。方法本研究回顾性分析262例行根治性同步化疗的宫颈鳞癌患者,对所有患者的高危临床靶区(high-risk clinical target volume,HR-CTV)和低危临床靶区(low-risk clinical target volume,LR-CTV)的剂量分别与复发情况进行了分析,使用受试者工作曲线(Receive receive operating characteristic,ROC)计算最佳照射剂量截断值,依据各靶区的剂量截断值分为高剂量组和低剂量组,分析不同剂量参数下患者的总生存期(overall survival,OS),疾病无进展生存期(progression-free survival,PFS)、局部控制率(local recurrence-free survival,LRFS)、无远处转移生存期(distant metastasis-free survival,DMFS)及毒副反应。结果 HR-CTV高剂量组与LR-CTV高剂量组的患者5年LRFS分别优于低剂量组(P <0. 05),而OS、PFS、DMFS差异均无统计学意义(P>0. 05)。Cox回归分析显示LR-CTV是影响局部控制率的独立因素(P=0. 01)。LR-CTV高剂量组的患者中照射剂量的升高与局部控制率无关联(P> 0. 05),同时HR-CTV高剂量组的患者急性肠道毒副反应明显增加(P <0. 05)。结论 LR-CTV高剂量组的患者具有更好的局部控制率和可控的毒副作用,提示LR-CTV>68 gy可能是目前宫颈鳞癌患者较为恰当的放疗剂量,进一步提高LR-CTV的放疗剂量对局部控制率无改善,且提高了毒副反应的发病风险。

Objective This study was aim to analyze patients with squamous carcinoma of the cervix(SCC)in regards to the effect of radiotherapy dose on the local control and toxicity of the patients,and to investigate whether higher brachytherapy dose delivery lead to a better outcome.Methods A retrospective review of brachytherapy delivered in 262 patients of cervical cancer were evaluated for dosimetry and outcomes.ROCcurve was used to identify the optimal cut-off point of continuous tumor parameters and divide patients into subgroups.Significance of radiotherapy dose parameters on OS,PFS,LRFS,DMFS,and toxicity was evaluated.Results In the univariate analysis,for both HR-CTV and LR-CTV,the high dose grouphave a better LRFS than low-dose groups(P<0.05),while no association of dose of HR-CTV or LR-CTV and OS,PFS,DMFS were found for all patients(P>0.05).LR-CTV remains significance after adjusted for age and FIGO stage.Moreover,in the high-dose LR-CTV group,there is no association between dose of LR-CTV and LRFS was found,however,higher dose of HR-CTV significant associated with higher ratio of side effect was found,meanwhile the intestinal side effects obviously raise up in the HR-CTV high-dose group(P<0.05).Conclusion The high-dose of LR-CTV is associated with favorable outcomes and low toxicity,supporting that LR-CTV>68 Gy might be a safety and efficacy dose of radiotherapy to the SCC paients.However,further improved in dose had no significant benefit on local control rate,and it might increase the risks of toxicity.