摘要
目的比较Varian Clinac ix带均整过滤器(flattening filter,FF)和不带均整过滤器(flattening filter free,FFF)治疗模式对容积立体定向消融放射治疗(SABR-VMAT)局限性前列腺癌剂量学的影响。方法对9例局限性前列腺癌患者的治疗计划回顾分析。分别给予35 Gy处方剂量,总分次为5次。采用6MV-FF和6MV-FFF模式为该9例患者设计SABR-VMAT计划,分析2种治疗模式对肿瘤剂量CI,HI及危及器官(OARs)的影响;通过模拟实施治疗的方式比较2种治疗模式对治疗时间的影响。结果 FFF和FF治疗计划都有很好的CI,HI和CN,OARs的剂量也能满足预先设置的剂量限值。在2种治疗模式下,靶区及OARs的剂量没有显著的差异,靶区外2 cm处的近似最大剂量FFF略微优于FF,分别为17.4 Gy和17.8 Gy,但没有统计学意义。FFF的治疗时间(2.5 min)明显的低于FF(3.6 min)。结论SABR-VMAT FFF模式治疗局限性前列腺癌在不影响肿瘤及危及器官剂量分布的情况下减少治疗时间,有一定的临床实用价值。
Objective To study the differences in VMAT-SABR treatmen plans dose distribution using Varian Clinac ix with flattening filter（ FF） and flattening filter-free（ FFF） modes for localized prostate cancer. Methods Retrospective analyzed the treatment plans of 9 patients with localized prostate cancer. Treatment plans in 6 MV-FF and 6 MV-FFF modes for each patients were designed,all plans prescribed 35 Gy in 5 fractions of 7 Gy each. Analyzed the impact on CI and HI of cancer dose distribution and OARs dose distribution in 2 VMAT-SABR modes and also analyzed the treatment time differences in simulating treatment delivery. Results For all plans,the dose distribution of cancer have good CI、HI and CN,and the dose of OARs can meet dose limits as well; There had no significant difference in dose distribution of cancer and OARs with 2 VMAT-SABR modes,the near-max dose at 2 cm outside cancer were 17. 4 Gy and 17. 8 Gy for FFF and FF modes respectively with no statistically significant difference; FFF mode had less treatment delivery time than FF,2. 5 min vs 3. 6 min. Conclusion Under the circumstance of no significant change of cancer and OARs dose distributions,the FFF mode VMAT-SABR can reduce treatment delivery time campared with FF mode. FFF mode VMAT-SABR has clinical practical value for localized prostate cancer.
出处
《实用癌症杂志》
2017年第9期1557-1560,共4页
The Practical Journal of Cancer
