摘要
目的模拟室性心动过速(VT)患者行立体定向消融体部放疗,探索质子调强放疗(IMPT)的剂量学优势。方法对资料完整的5例患者的胸部定位CT图像均分别勾画左心室的心尖部、心前壁、间隔壁、下壁、外侧壁心肌全层共25个大体靶体积(GTV)。GTV三维外扩5 mm为ITV,ITV外扩3 mm为PTV。每个靶区均分别设计容积调强弧形治疗(VMAT)与IMPT计划。处方剂量为单次25 Gy(RBE)。比较两种计划靶区及危及器官剂量参数。结果中位ITV体积45.40 cm^3(26.72~67.59 cm^3),所有计划均达到足够的靶区覆盖(ITV V95%Rx≥99%)。相比VMAT计划,IMPT组全心、心包及靶区外心脏组织Dmean分别降低44.52%、44.91%、60.16%,左前降支D0.03 cm^3降低17.58%(P<0.05)。按病灶部位分析后发现,IMPT仍可降低绝大多数危及器官剂量,但当病灶位于前壁及心尖时左前降支D0.03 cm^3两者相近,病灶位于前壁或下壁时左回旋支D0.03 cm^3也相近(P>0.05)。结论模拟VT患者立体定向消融体部放疗时,VMAT与IMPT计划均满足临床剂量学要求;而IMPT可降低正常心脏组织受量,具有降低缺血性心脏病、心包炎或心包积液等并发症的潜在获益。
Objective To evaluate the dosimetric properties of intensity-modulated proton therapy(IMPT)plans for simulated treatment planning in patients with ventricular tachycardia(VT)using stereotactic ablative body radiotherapy(SABR),in comparison with the volumetric-modulated arc therapy(VMAT).Methods A total of 25 gross target volume(GTV)of the apical,anterior,septal,inferior and lateral wall of the left ventricle(LV)were delineated on the CT simulation images of 5 patients with complete data.An additional 5 mm GTV margin was added to the internal target volume(ITV),and an additional 3 mm ITV margin was added to the planning target volume(PTV).VMAT and IMPT plans were designed in each target area.Dose prescription was 25 Gy(RBE)in a single fraction.The dosimetric differences of ITV and organ at risk(OAR)were compared between VMAT and IMPT.Results The median volume of ITV was 45.40 cm^3(26.72-67.59 cm^3).All plans had adequate target coverage(V95%Rx≥99%).Compared with the VMAT plans,IMPT reduced the Dmean of whole heart,pericardium and non-target cardiac tissues(relative difference)by 44.52%,44.91%and 60.16%,respectively,which also reduced D0.03 cm^3 of the left anterior descending artery by 17.58%(P<0.05).After stratified analysis according to the lesion sites,IMPT could still reduce the dose of most OAR.However,the D0.03 cm^3 of LAD and LCX for the lesions in the anterior wall of LV,the D0.03 cm^3 of LCX in the inferior wall and D0.03 cm^3 of LAD in the apical wall did not significantly differ(both P>0.05).Conclusions Both VMAT and IMPT plans can meet the clinical dosimetric requirements when SABR is simulated in patients with VT.However,IMPT can lower the dose of normal heart tissues,which has the potential benefit of reducing the risk of complications,such as ischemic heart disease,pericarditis/pericardial effusion,etc.
作者
任雪盈
高献书
贺鹏康
赵智磊
赵波
白赟
马茗微
秦尚彬
张敏
周菁
Ren Xueying;Gao Xianshu;He Pengkang;Zhao Zhilei;Zhao Bo;Bai Yun;Ma Mingwei;Qin Shangbin;Zhang Min;Zhou Jing(Department of Radiation Oncology,Peking University First Hospital,Beijing 100034,China;Department of Cardiology,Peking University First Hospital,Beijing 100034,China;Hebei Yizhou International Proton Medical Center,Zhuozhou 072750,China)
出处
《中华放射肿瘤学杂志》
CSCD
北大核心
2020年第6期466-471,共6页
Chinese Journal of Radiation Oncology
基金
北京市自然科学基金(7182164)
北京市科学技术委员会资助,首都特色课题(Z161100000516041)。
关键词
室性心动过速
立体定向消融体部放疗
容积调强弧形治疗
质子调强放疗
剂量学
Ventricular tachycardia
Stereotactic ablative body radiotherapy
Volumetric-modulated arc radiotherapy
Intensity-modulated proton therapy
Dosimetry
