CAJ | 학술논문

目的比较食管癌VMAT与静态IMRT的剂量学差异,探索VMAT的可行性.方法 2011-2012年入组食管癌患者30例,颈段、胸下段各5例,胸上段、胸中段各10例.用医科达Oncentra 4.1计划系统分别设计单弧VMAT和IMRT计划,PTV处方剂量60Gy分30次.用Delta 4进行剂量验证.配对t检验或Wilcoxon符号检验比较两组计划PTV、OAR受量、机器跳数及有效治疗时间.结果两组计划均能满足临床剂量学要求.与IMRT相比VMAT的CI值好(P =0.008),脊髓Dmax更低(P=0.032),但心脏V30、V40、Dmean增高(P=0.041、0.012、0.002);颈段病变VMAT的肺V5-V15及MLD增高(P=0.002～0.022、0.022);胸上段病变VMAT的心脏V30、Dmwan增高(P=0.030、0.026),脊髓Dmax减低(P=0.006);胸中段病变VMAT的肺V10-V20减低(P =0.015～0.041);胸下段病变两组计划各项指标相近(P=0.262～0.998).3 mm/3％标准下γ通过率VMAT为92.75％,IMRT为92.98％ (P =0.826).机器跳数VMAT为460.66 MU,IMRT为522.55 MU,平均减少11.84％ (P =0.001).有效治疗时间VMAT为139.6 s,IMRT为298.73 s,缩短了53.27％(P=0.000).结论在靶区覆盖率相似前提下,VMAT可降低部分OAR受量,并能改善CI值、减少机器跳数、缩短有效治疗时间.Synergy平台上的VMAT计划剂量稳定可靠.
목적 비교식관암VMAT여정태IMRT적제량학차이,탐색VMAT적가행성.방법 2011-2012년입조식관암환자30례,경단、흉하단각5례,흉상단、흉중단각10례.용의과체Oncentra 4.1계화계통분별설계단호VMAT화IMRT계화,PTV처방제량60Gy분30차.용Delta 4진행제량험증.배대t검험혹Wilcoxon부호검험비교량조계화PTV、OAR수량、궤기도수급유효치료시간.결과 량조계화균능만족림상제량학요구.여IMRT상비VMAT적CI치호(P =0.008),척수Dmax경저(P=0.032),단심장V30、V40、Dmean증고(P=0.041、0.012、0.002);경단병변VMAT적폐V5-V15급MLD증고(P=0.002～0.022、0.022);흉상단병변VMAT적심장V30、Dmwan증고(P=0.030、0.026),척수Dmax감저(P=0.006);흉중단병변VMAT적폐V10-V20감저(P =0.015～0.041);흉하단병변량조계화각항지표상근(P=0.262～0.998).3 mm/3％표준하γ통과솔VMAT위92.75％,IMRT위92.98％ (P =0.826).궤기도수VMAT위460.66 MU,IMRT위522.55 MU,평균감소11.84％ (P =0.001).유효치료시간VMAT위139.6 s,IMRT위298.73 s,축단료53.27％(P=0.000).결론 재파구복개솔상사전제하,VMAT가강저부분OAR수량,병능개선CI치、감소궤기도수、축단유효치료시간.Synergy평태상적VMAT계화제량은정가고.
Objective To compare the dosimetric difference between volumetric modulated arc therapy (VMAT) and static intensity modulated radiotherapy (IMRT) for esophageal carcinoma.Methods Thirty patients were selected in this study,including 5 cases in the cervical,5 the lower thorax,10 the upper thorax and 10 the middle thorax.VMAT plans with a single arc and IMRT plans with five fields designed for each patients.Planning target volume (PTV) were prescribed to 60 Gy in 30 fractions.Delta 4 was used to verifie the dosimetric of treatment plans.Using paired t-test or Wilcoxon signed-test to compare the dose distribution on planning and organs at risk (OAR).The monitor units and treatment time were also evaluated to measure the treatment efficiency.Results All the VMAT and IMRT plans can satisfy the clinical dosimetry requirements.VMAT had better conformal index for PTV than IMRT (P =0.008).VMAT was better than IMRT by reducing the Dmax of spinal cord (P =0.032),while the V30,V40 and Dmean of heart were significantly higher (P =0.041,0.012,0.002).For cervicals,the V5,V10,V15 and mean dose of lung were significant higher in VMAT than those in IMRT (P =0.002-O.002,0.002).For uppers,the values of heart V30 and Dmean were significantly larger in VMAT than IMRT (P =0.030,0.026).However,the Dmax of spinal cord in VMAT was lower than IMRT (P =0.006).For middles,VMAT reduced V10,V15,V20 of lung (P =0.015,0.028,0.041).There were no significant differences between VMAT and IMRT in the lowers (P =0.262-0.998).The 3 mm/3％ γ pass rate was 92.75％ for VMAT and 92.98％ for IMRT (P =0.826).The average MU of VMAT (460.66 MU) was reduced by 11.84％ compared with IMRT (522.55 MU) (P=0.001).The delivery time of VMAT (139.6s) compared with IMRT (298.73 s) was reduced by an average of 53.27％ (P =0.000).Conclusions Compared with IMRT,VMAT improved the OARs dose sparing and the target CI with similar dose distribution to the target.VMAT required fewer MU,shorten the treatment time significantly.The implementation of Synergy is stable and reliable.