【摘要】 目的探讨为早期乳腺癌保乳术后的全乳腺放疗探寻合适的容积旋转调强放疗(volumetric modulated arc therapy,VMAT)的物理计划设计方案。方法在pinnacle TPS中为10例接受保乳术后的左侧乳腺癌患者设计VMAT计划,采用两种不同的弧段设计方式,为每例患者设计两种不同的VMAT计划,分别是连续弧形线上运动容积旋转调强放疗(continuous volumetric modulated arc therapy,cVMAT)和切线弧形线上运动容积旋转调强放疗(tangential volumetric modulated arc therapy,tVMAT)。比较和分析两种物理计划中PTVin的CI、HI、GI及同侧肺、心脏、对侧肺、对侧乳腺的剂量。结果 cVMAT技术下靶区的CI、HI优于tVMAT,差异均有统计学意义(P<0.05);当剂量>2000 cGy时,cVMAT的GI值始终小于tVMAT。在同侧肺和心脏保护上,两种方法比较,差异无统计学意义(P>0.05);在对侧乳腺和对侧肺的保护上,tVMAT优于cVMAT,差异有统计学意义(P<0.05)。结论两种VMAT计划设计方法各有优劣,cVMAT能实现更好的靶区剂量均匀性和适形度,而tVMAT在对侧乳腺和对侧肺的保护上有优势。因此,可以根据不同的临床考量,选择不同的VMAT计划设计方法。更多还原

【Abstract】 Objective To search the suitable volumetric modulated arc therapy(VMAT) physical schemes for the whole-breast radiotherapy after breast-conserving surgery of left-sided breast cancer.Methods 10 cases of left-sided breast cancer patients who had received the breast-conserving surgery were randomly selected for this study,and 2 physical schemes,which were continuous volumetric modulated arc therapy(cVMAT),and tangential volumetric modulated arc therapy(tVMAT),were designed for every patient in pinnacle TPS.The CI,HI and GI in PTVin,as well as the doses in the ipsilateral lung,heart,contralateral lung and contralateral breast in the 2 physical schemes were compared and analyzed.Results The CI and HI of the target volume under the cVMAT technique were superior to that under tVMAT,with statistical differences in both CI and HI(P<0.05).When the dose >2000 c Gy,the GI value of cVMAT was always smaller than that in tVMAT.In terms of heart and ipsilateral lung protection,there were also no statistical difference in the involved statistical parameters among the two schemes(P>0.05).With regard to the protection of the contralateral lung and the contralateral breast,tVMAT was superior to cVMAT,and there were statistical differences in the involved indicators(P<0.05).Conclusion Two kinds ofVMAT methods have their own advantages and disadvantages.The CI and HI of the target volume and dose-fall under the cVMAT technique were superior to that under tVMAT,and tVMAT has the advantages on the protection of the contralateral lung and contralateral breast.So,we should choose different methods ofVMAT plan design according to different clinical considerations..更多还原