2015 年第 4 期 第 13 卷

ICRU_83报告推荐方式评估宫颈癌术后辅助调强放疗与传统放疗方式的差异及可行性

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关键词：宫颈癌调强放疗传统放疗ICRU83

• 摘要：
• 【摘要】【目的】 ICRU83报告推荐方式评估宫颈癌术后辅助调强放疗和传统放疗方式的差异及可行性。 【方法】 回顾性分析10例宫颈癌术后IMRT计划和模拟传统二维二野等中心放疗计划的DVH数据。统计PTV的靶区体积、D100、D98、D95、D50、Dmean、D2、D0，计算均匀性指数HI；以D50评估不同方式对放疗剂量的影响；统计危及器官的DVH参数，包括膀胱和直肠的体积、Dmax、V40、V50、D1cc、D2cc、D2%和Dmean；骨盆的V10、V20和V30；小肠的V10-40，Dmean，Dmax，D2。利用SPSS 19.0软件进行统计分析。【结果】 以D50评估调强计划的PTV剂量较二维计划提高4.47±3.62%，其实际差值为200±157cGy（t=4.2，p=0.001）。调强计划中骨盆的V10和V20高于二维计划，分别为95.9±1.7% vs 56.4±4.0%，p=0.000和77.9±7.2% vs 47.5±5.0%，p=0.000；骨盆的V30在两种放疗计划差异无统计学意义。调强放疗中小肠的V10和V20明显高于二维计划，V40低于二维计划。调强计划中膀胱和直肠的V40、Dmean较二维计划降低，而以D1cc、D2cc、D2%和Dmax为指标评估高剂量区的差异无统计学意义。【结论】 ICRU83报告推荐方式适用于IMRT计划评估；IMRT较传统放疗方式提高了靶区剂量，增加了骨盆和小肠的低剂量受照体积，降低了膀胱和直肠的整体受照剂量，仍存在小体积较高剂量。若采用D50作为评估标准，可考虑降低剂量4.47±3.62%。
• [Object] To evaluate the difference and feasibility of intensity-modulated radiotherapy and conventional 2D radiotherapy for postoperative cervical cancer with ICRU83 report method. [Methods] Retrospectively analysis the DVH parameters of 10 IMRT plans and 10 conventional 2D plans simulated on the same planning CT. The DVH parameters evaluated include D100(Dmax), D98(Dnear-min), D95, D50(Dmedia), Dmean, D2(Dnear-max), D0(Dmax) for PTV, Dmax、V40、V50、D1cc、D2cc、D2 for rectum and bladder, V10,V20,V30 for pelvic bones, V10-40，Dmean，Dmax and D2 for small intestine. [Results]: PTV D50 is raised by 4.47 ± 3.62% in IMRT plans than 2D plans, the actual value was 200 ± 157cGy (t=4.2,p=0.001). V10 and V20 for pelvic bones in IMRT was higher than in 2D plans, V30 for pelvic bones in IMRT and 2D plans showed no statistical significance. V10 and V20 for small intestine was higher and V40 was lower in IMRT plans than 2D plans. V40 and Dmean was reduced in IMRT plans, while there still remains small high dose volume. [Conclusion]The method recommended by ICRU83 report is feasible. IMRT potentially increased dose to the target volume, reduced dose for bladder and rectum while small high dose volume still remain. IMRT increased low-dose volume for small intestine and pelvic bones. With D50 as a standard for dose evaluation, prescribed dose should be decreased by 4.47±3.62%。