摘要
目的研究螺旋断层放疗(helical tomotherapy, HT)与容积旋转调强放疗(volumetric modulated arc therapy, VMAT)在同时性双侧乳腺癌术后放疗中的剂量学、治疗出束时间差异, 探讨HT技术的临床应用可行性。方法回顾性分析并选取2017年2月至2022年5月于广西医科大学第四附属医院行改良根治术后放疗的9例同时性双侧乳腺癌患者为研究对象, 对每例患者分别使用Precision计划系统制定HT计划和RayStation计划系统制定VMAT计划。所得所有计划按照计划类型分为HT组和VMAT组。采用配对样本t检验比较两种放疗技术的靶区和危及器官(organ at risk, OAR)的剂量学参数及治疗出束时间。结果两组计划均能满足临床治疗要求。HT组的靶区覆盖度(D_(95%)和V_(100%))、适形指数CI、平均剂量D_(mean)和中位剂量D_(50%)均优于VMAT组, 差异均有统计学意义(t=-3.21、-3.39、-5.03、3.76、4.97, P < 0.05);两组计划的靶区最大剂量D_(2%)、最小剂量D_(98%)、高剂量体积V_(107%)和V_(110%)、均匀性指数HI的差异无统计学意义(P > 0.05)。OAR方面, HT组的双肺V20、D_(mean)均明显低于VMAT组, 但双肺V5明显高于VMAT组, 差异均有统计学意义(t=-3.01、3.83、-2.81, P < 0.05);同时HT组明显降低了心脏的V_(20)、V_(30)、V_(40)、D_(mean)以及肝脏的V20、D_(mean), 差异均有统计学意义(t=3.76、-2.83、-2.74、5.93、4.57、4.48, P < 0.05);其他OAR脊髓、甲状腺、肱骨头的受照剂量差异无统计学意义(P > 0.05)。HT组的治疗出束时间显著高于VMAT组(t =11.32, P < 0.05)。结论与VMAT相比, HT具备更大的剂量学优势, 能提供更优的靶区覆盖度、适形度和平均剂量, 且可明显降低OAR双肺、心脏和肝脏的整体受照剂量, 但双肺的低剂量区V5、治疗时间多于VMAT, 不过仍满足临床治疗需求, 故可考虑将HT技术应用于同时性双侧乳腺癌的改良根治术后放疗。
Objective To study the differences in the dosimetry and delivery time between helical tomotherapy(HT)and volumetric modulated arc therapy(VMAT)in postoperative radiotherapy of synchronous bilateral breast cancer(SBBC)and to explore the feasibility of clinical application of the HT technology.Methods A retrospective analysis was conducted for nine SBBC patients who underwent modified radical postoperative radiotherapy in the Fourth Affiliated Hospital of Guangxi Medical University from February 2017 to May 2022.For each patient,the Precision planning system was used to formulate the HT plan,and the RayStation planning system was employed to develop the VMAT plan.All plans obtained were divided into HT group and VMAT group according to plan type.The paired sample t-test was used to compare the dosimetric parameters of the target volume and organ at risk(OAR)and delivery time between the two radiotherapy technologies.Results The plans of both groups could meet the clinical treatment requirements.The coverage(D_(95%)and V_(100%)),conformity index(CI),average dose(D_(mean)),and median dose(D50%)of the target volumes in the HT group were better than those in the VMAT group,and the differences were statistically significant(t=-3.21,-3.39,-5.03,3.76,4.97,P<0.05).The differences in the maximum dose(D2%),minimum dose(D_(98%)),high dose volumes(V_(107%)and V_(110%)),and homogeneity index(HI)of the target volumes between the two groups were not statistically significant(P>0.05).Regarding the OAR,the V_(20) and D_(mean) of both lungs in the HT group were significantly lower than those in the VMAT group,but the irradiation volume V5 of both lungs in the HT group was significantly higher than that in the VMAT group(t=-3.01,3.83,-2.81,P<0.05).Moreover,V_(20),V_(30),V_(40),and D_(mean) of heart and the V_(20) and D_(mean) of liver in the HT group were significantly lower than those in the VMAT group,with statistically significant differences(t=3.76,-2.83,-2.74,5.93,4.57,4.48,P<0.05).There was no significant difference in the radiation doses to other OARs(spinal cord,thyroid gland,and humerus head,P>0.05).The delivery time of the HT group was significantly higher than that of the VMAT group(t=11.32,P<0.05).Conclusions Compared with VMAT,HT has greater dosimetric advantages,and can provide higher target coverage,conformability and average dose,and significantly reduce the overall radiation doses to both lungs,heart,and liver in OARs.However,the irradiation volume V5 at low-dose areas of both lungs and the delivery time in the HT group are higher than those in the VMAT group,but still meet the clinical treatment requirements.Therefore,it is feasible to apply the HT technology to the modified radical postoperative radiotherapy of SBBC.
作者
贺先桃
龙雨松
谭军文
李钢
冯永富
杨慧
陆颖
王占宇
He Xiantao;Long Yusong;Tan Junwen;Li Gang;Feng Yongfu;Yang Hui;Lu Ying;Wang Zhanyu(Department of Oncology,Fourth Affiliated Hospital of Guangxi Medical University,Liuzhou 545005,China)
出处
《中华放射医学与防护杂志》
CAS
CSCD
北大核心
2022年第12期943-949,共7页
Chinese Journal of Radiological Medicine and Protection
基金
广西重点研发计划项目(2021AB12033)
广西卫生健康委员会自筹经费科研课题(Z20200421, Z20210401)。
关键词
双侧乳腺肿瘤
放射疗法
螺旋断层放疗
容积旋转调强放疗
剂量学
Bilateral breast neoplasms
Radiotherapy
Helical tomotherapy
Volumetric modulated arc therapy
Dosimetry
