宫颈癌调强放疗同步补量与常规照射剂量分布比较

Comparing of dose distribution between intensity-modulated radiotherapy simultaneous integrated boost and conventional radiotherapy for cervical cancer patients

目的评价调强放疗同步补量（IMRTSIB）代替常规照射（全盆外照射加腔内放疗）治疗局部进展期宫颈癌（LACC）的可行性。方法根据子宫的不同位置选择5例LACC患者，分别制订常规放疗和IMRTSIB计划，比较2种放疗方式靶区的剂量分布。结果子宫前位、水平位、后位以及偏位时IMRTSIB可以为靶区提供优于常规照射均匀、足量的剂量分布，降低危险器官（直肠、膀胱和小肠）受照体积和剂量；IMRTSIB能够得到较常规放疗更高的A、B点和宫底剂量。但如果小肠邻近或环绕子宫时靶区则欠量。结论剂量学研究证明LACCIMRTSIB在不同子宫位置（过度前倾前曲位除外）时肿瘤靶区的剂量分布优于常规放疗。

Objective To assess the feasibility of applying intensity-modulated radiotherapy （IMRT） simultaneous integrated boost （SIB） to replace conventional radiotherapy （CR） plus brachytherapy of whole pelvis in locally advanced cervical cancer （LACC）. Methods Five LACC patients based difference position of uterus were chosen and worked out CR and IMRT SIB plans respectively. Dose distributions were compared between IMRT SIB and CR. Results When uterus was in ante-, neutral-, retro-position and deviation respectively, IMRT SIB could provide enough and homogeneous close distribution for target volume and reduce irradiated volumes and doses for organs at risk （recta, bladder and small intestine） than CR. The doses of the A, B, and fundus of uterus were higher in IMRT SIB than CR. However, in case of small intestine was close to or encircled the uterus, the targets volume dose would be inadequacy. Conclusions LACC IMRT SIB＇s close distribution is better than CR （except excess ante-position） and may help to treat those patients who couldn＇t be suitable with brachytherapy.