放射治疗中宫颈癌患者腹部体轮廓变化对于剂量影响研究

摘要

Objective:To study the effect of patient abdomen volume changes on patient received dose during cervical cancer intensity-modulated radiotherapy.Methods: Fifteen cervical cancer patients previously treated with IMRT were selected . CBCT images acquired before the first treatment and the planning CT images were fused in Pinnacle v9.2 treatment planning system. The abdomen outline volumme variation between treatment and planning was collected and analysed, and the dosimetric changes of the target GTV、CTV and the OAR such as intestine、bladder、rectum were acquired in the treatment planning system.Results: The correlation coefficients for V40 of bladder 、intestine 、rectum and the abdomen outline variation were -0.75、-0.87 and -0.79.The correlation coefficients for CTV minimum dose and outline variation was -0.94, for CTV mean dose was -0.95, for CTV maximum dose was -0.88.The correlation coefficients for GTV,the minimum,mean,maximum dose were 0.71、-0.96、-0.91,respectively. Conclusions: Abdomen volume changes were inversely related to the dose patient received.%目的：研究宫颈癌放射治疗中患者腹部轮廓变化对患者受照剂量的影响。方法：选择15例接受调强放射治疗的宫颈癌患者。在PinnacleV9.2治疗计划中把治疗前扫描得到的CBCT图像和计划CT图像进行融合配准。统计分析患者实际治疗时和首次放疗计划时的腹部体积变化，并在计划系统中模拟获得大体肿瘤区（GTV），临床肿瘤区（CTV），小肠、膀胱和直肠等危及器官在剂量学上的变化。结果：膀胱、小肠和直肠的40Gy剂量体积（V40）与外轮廓差值的相关系数分别为-0.75、-0.87、-0.79。CTV最小、平均、最大剂量与外轮廓差值的相关系数：-0.94、-0.95、-0.88。GTV的最小、平均、最大剂量的相关系数为0.71、-0.96、-0.91。结论：放射治疗过程中腹部体积变化对宫颈癌的剂量影响呈负相关。