机器跳数优化对鼻咽癌容积旋转调强放疗的影响研究  

Effect of monitor unit optimization on volumetric modulated arc therapy planning for nasopharyngeal carcinoma

作　　者：曾华驱 张慧[1,3] 吴齐兵[4] ZENG Hua-qu;ZHANG Hui;WU Qi-bing(School of Biomedical Engineering,Anhui Medical University,Hefei 230032,China;Radiotherapy Center,Gaozhou People's Hospital,Gaozhou 525200,Guangdong Province,China;Department of Radiation Oncology,the First Affiliated Hospital of University of Science and Technology of China,Hefei 230032,China;Department of Radiation Oncology,the First Affiliated Hospital of Anhui Medical University,Hefei 230032,China)

机构地区：[1]安徽医科大学生物医学工程学院,合肥230032 [2]高州市人民医院放疗中心,广东高州525200 [3]中国科学技术大学附属第一医院肿瘤放疗科,合肥230032 [4]安徽医科大学第一附属医院放疗科,合肥230032

出　　处：《医疗卫生装备》2025年第2期56-62,共7页Chinese Medical Equipment Journal

基　　金：广东省医学科学技术研究基金项目(B2022275);茂名市科技专项(2022S010)。

摘　　要：目的:探讨机器跳数优化对鼻咽癌容积旋转调强放疗的影响。方法:回顾性选取2022年10月至2023年3月在某院经病理诊断为鼻咽癌的21例患者,为每位患者设计双弧容积调强放疗计划,通过光子优化算法进行计划优化,不使用机器跳数目标(monitor unit objective,MUO)工具进行设计,将该计划命名为base。保持计划base的参数设置,仅使用MUO工具并将其Maximum MU参数值设置为计划base的总机器跳数的30%,Strength参数值分别设置为50、80和100后进行重新优化,得到计划S50、S80和S100。比较计划S50、S80和S100与计划base的靶区和危及器官剂量分布、机器跳数、出束时间以及γ通过率。采用SPSS 17.0软件进行统计学分析。结果:在计划S100中只有4例患者的PCTV2靶区D98%剂量相比于计划base下降幅度超过4%。在计划S80中只有2例患者的PGTV和PGTVnd的Dmax剂量以及PCTV2的D98%剂量相比于计划base下降幅度超过3%,但下降幅度未超过4%,其他靶区剂量参数变化幅度多数小于2%。相对于计划base,计划S50、S80、S100均会增加脑干的Dmax,差异有统计学意义(P均<0.05),但最大增量不超过1.5%。计划S50可以降低左右腮腺的D50%和Dmean,计划S80可以降低左右腮腺的Dmean和左腮腺的D50%,差异有统计学意义(P<0.001),计划S100相对于计划base会增大左右腮腺的D50%和Dmean、脊髓的Dmax,差异有统计学意义(P均<0.05)。计划S80和S100相对于计划base会提高甲状腺的V40,差异有统计学意义(P<0.05)。计划S50、S80和S100相对于计划base机器跳数分别平均降低5.1%、21.5%和30.9%,4种计划的平均出束时间基本保持在2.5 min。在1%/1 mm条件下,计划base、S50、S80和S100的γ通过率依次增加。结论:将机器跳数优化应用于鼻咽癌容积旋转调强放疗中可以在保证靶区剂量覆盖和危及器官保护的同时,有效减少计划的机器跳数,提高1%/1 mm条件下的γ通过率。Objective To investigate the effect of monitor unit(MU)optimization on volumetric modulated arc therapy(VMAT)for nasopharyngeal carcinoma(NPC).Methods Totally 21 NPC patients confirmed pathologically at some hospital from October 2022 to March 2023 were selected retrospectively,and for each patient a double-arc VMAT plan named base was designed without using the monitor unit objective(MUO)tool and optimized by the photon optimization algorithm.With the parameter kept constant,Plan base was reoptimized with only the MUO tool by regulating its Maximum MU to 30%of the total MU of Plan base and setting Strength values as 50,80 and 100 respectively to obtain Plan S50,S80 and S100.Plan base was compared with Plan S50,S80 and S100 in terms of dose distributions of the target volumes and organs at risk(OARs),MU,beam-on time andγpass rate.SPSS 17.0 software was used for statistical analysis.Results In Plan S100 only 4 patients had a decrease of more than 4%in the D98%to the PCTV2 target volume compared with that in Plan base.In Plan S80 only 2 patients had a decrease of between 3%and 4%in the Dmax to PGTV and PGTVnd and D98%to PCTV2 when compared with those in Plan base,and most of the dosimetric parameters to the other target volumes had the changing amplitudes lower than 2%.When compared with Plan base,Plan S50,S80 and S100 all increased the Dmax to the brainstem significantly(all P<0.05),with the maximum increment not exceeding 1.5%.In Plan S50 the D50%and Dmean to the right and left parotid glands were lowered,and in Plan S80 there were decreases found in the Dmean to the right and left parotid glands and D50%to the left parotid gland,with statistically significant differences(P<0.001),and in Plan S100 the D50%and Dmean to the right and left parotid glands and the Dmax to the spinal cord increased significantly when compared with those in Plan base(all P<0.05).In Plan S80 and S100 the V40 of the thyroid relatively rose statistically when compared with that in Plan base(P<0.05).In Plan S50,S80 and S100 the MU was decr

关 键 词：鼻咽癌 容积旋转调强放疗 机器跳数优化 机器跳数 MUO工具 

分 类 号：R318[医药卫生—生物医学工程] R815[医药卫生—基础医学]