直肠癌术前大分割短程放疗中容积旋转调强和固定野调强的剂量学比较  

Dosimetric comparison of Rapid Arc with fixed field intensity-modulated radiotherapy in the short-course preoperative hypofractionated radiotherapy of rectal cancer

作　　者：刘建庭[1] 景娜[1] 孟慧敏[1] 郑亚琴[1] 邢晓汾[1] 陈明晓[1] 

机构地区：[1]山西省肿瘤医院(研究所)放疗中心,山西太原030013

出　　处：《现代肿瘤医学》2017年第23期3858-3861,共4页Journal of Modern Oncology

摘　　要：目的:近年来容积旋转调强(Rapid Arc)技术在放疗计划设计中已经广泛使用,本文对比Rapid Arc和常规调强(IMRT)二者在直肠癌术前大分割短程放疗计划设计中的剂量学差异,探讨其适宜的放疗技术。方法:分别为10例已行放疗的直肠癌术前大分割短程患者设计Rapid Arc和7F-IMRT两种计划,应用剂量体积直方图比较分析靶区和危及器官的剂量学差异及治疗参数。结果:两种技术放疗计划均能满足临床剂量要求。7F-IMRT计划靶区的适行指数(CI)和均匀指数(HI)优于RapidA rc,但靶区的平均剂量(Dmean)二者无差异。危及器官的保护例如小肠的最大剂量(Dmax)和V25、膀胱的V25和双侧股骨头的V10和Dmean等,7F-IMRT优于RapidA rc,危及器官其余参数差异不大。机器跳数(MU)和实际治疗时间差异明显,RapidA rc明显优于7F-IMRT。结论:直肠癌术前大分割短程放疗中IMRT可能是较为适宜的技术。Objective：The RapidArc technology has been widely used in designing the radiotherapy plan in recent years. The appropriate radiotherapy technology is to discussed in this paper by comparing the dosimetric parameters between RapidArc and IMRT in the short - course preoperative hypofractionated radiotherapy of rectal cancer. Methods：Ten preoperative patients with rectal cancer were selected to be treated with a dose of 25 Gy/5 fractions at plan- ning target volume（PTV）. Two techniques, intensity -modulated radiation therapy （IMRT）and RapidArc, were used respectively to compare treatment times, monitor units, target conformal index, homogeneity index and dose - volume histogram data. Results： Among the two radiotherapy techniques, which met the clinical requirements. Conformal index of the target （PTV）in RapidArc and IMRT plans were （0. 880± 0. 025） and （0. 891 ± 0. 014） respectively （P = 0. 032 ）. Homogeneity index of PTV in RapidArc and IMRT plans were （0. 052 ± 0. 008 ） and （0.045 ± 0. 008 ） respectively （ P = 0. 000）. But, there was no significant difference about the mean dose （ D ） of PTV. Between IMRT and RapidArc plans, the statistically significant differences were found in V25 and D of the intestine, V25 of the blad- der, V10 and D of Femoral Heads. Compared with the IMRT plan, the mean monitor units in the RapidArc plan was significantly reduced by 31% （P = 0. 000）. Conclusion： IMRT might be an appropriate radiotherapy technology that used for the short - course preoperative hypofractionated radiotherapy of rectal cancer.

关 键 词：直肠癌 短程放疗 容积旋转调强放疗 调强放疗 剂量学 

分 类 号：R735[医药卫生—肿瘤]