最小子野宽度对食管癌容积调强弧形治疗计划的影响  

Effect of the minimum segment width on quality of VMAT for esophageal cancer

作　　者：鄢佳文[1] 高靖琰 刘旭红[1] 朱思瑾 陈飞虎 YAN Jia-wen;GAO Jing-yan;LIU Xu-hong;ZHU Si-jin;CHEN Fei-hu(Department of Radiotherapy,the Third Affiliated Hospital of Kunming Medical University,Kunming 650000,Yunnan,China)

机构地区：[1]昆明医科大学第三附属医院放射治疗科,云南昆明650000

出　　处：《生物医学工程与临床》2023年第1期53-56,共4页Biomedical Engineering and Clinical Medicine

摘　　要：目的基于不同最小子野宽度(MSW)对于食管容积调强弧形放射治疗(VMAT)计划质量和执行效率的影响。方法随机选择15例食管癌患者,其中男性11例,女性4例;年龄45~68岁,中位年龄59岁。设计0.5 cm、1.0 cm、1.5 cm3种不同MSW的VMAT计划,保证其他计划参数不变。评价靶区均匀性指数(HI)、适形度指数(CI)和平均剂量及控制点数(CP)和机器跳数(MU)值,并进行三维剂量验证测量。结果不同MSW对危及器官的保护是相当的,在MSW 0.5 cm、1.5 cm时肿瘤靶区平均量GTV Dmean[(68.95±0.03)Gy vs(68.29±0.03)Gy]、在MSW 1.0 cm和1.5 cm时计划靶区(PTV)的HI差异有统计学意义(1.14±0.00 vs 1.13±0.00)(P<0.05);MSW 1.0 cm、1.5 cm时总MU和CP与0.5 cm比较,平均减少量分别为(12.5±4.1)%、(13.9±4.8)%和(28.5±5.4)%、(18.4±3.4)%。计划验证使用阈值为10%,3%/3 mm的Gamma分析方法,计划验证通过率分别为(96.73±0.27)%、(96.98±0.32)%、(97.25±0.42)%,差异无统计学意义,均能满足临床需求。结论增加MSW在保证计划食管癌的VMAT计划质量下,可以降低MU,提高计划执行效率,MSW为1.0 cm会是一个较优选择。Objective To study the influence of different minimum segment width(MSW)on volumetric modulated arc therapy(VMAT)plan quality and efficiency for esophageal cancer treatment.Methods A total of 15 patients with esophageal cancer were enrolled,which included 11 males and 4 females,aged 45-68 years old with median age of 59 years old.Three VMAT plans with 3 different MSW of 0.5 cm,1.0 cm and 1.5 cm were designed,and other plan parameters were remained.The homogeneity index(HI),conformity index(CI),mean dose,control points(CP)and monitor units(MU)of the target area were evaluated,and three-dimensional dose verification measurements were performed.Results The protection of different MSW for organs with risk was equivalent.There were significant differences in mean gross tumor volume(GTV)Dmeanbetween MSW 0.5 cm and MSW 1.5 cm[(68.95±0.03)Gy vs(68.29±0.03)Gy],and HI of PTV between MSW 1.0 cm and MSW 1.5 cm(1.14±0.00vs 1.13±0.00)(P<0.05).Compared with 0.5 cm MSW,the mean reduction of total MU and CP at 1.0 cm and 1.5 cm MSW were(12.5±4.1)%,(13.9±4.8)%and(28.5±5.4)%,(18.4±3.4)%,respectively.The Gamma analysis method with threshold of 10%and 3%/3 mm was used for plan verification,and passing rates of plan verification were(96.73±0.27)%,(96.98±0.32)%and(97.25±0.42)%,respectively;and the difference was no statistically significant,which all met the clinical requirements.Conclusion It is demonstrated that increasing MSW could reduce MU and improve efficiency of plan execution while ensuring quality of VMAT plan for esophageal cancer,and MSW of 1.0 cm is a better choice.

关 键 词：最小子野宽度 食管癌 容积调强弧形放射治疗(VMAT) 执行效率 

分 类 号：R735.1[医药卫生—肿瘤] R730.55[医药卫生—临床医学]