基于ArcCheck和电子射野影像装置脑瘤患者特异性容积调强放射治疗剂量验证过程容差限值与干预限值研究  

Study on TL and AL in the process of dose verification of specific VMAT for patients with brain tumor based on ArcCheck and EPID

作　　者：史传磊 高峰[1] 宫瑾 邱晓光[1] SHI Chuan-lei;GAO Feng;GONG Jin(Department of Radiotherapy,Beijing Tiantan Hospital,Capital Medical University,Beijing 100070,China;不详)

机构地区：[1]首都医科大学附属北京天坛医院放疗科,北京100070

出　　处：《中国医学装备》2023年第8期19-24,共6页China Medical Equipment

基　　金：首都卫生发展科研专项(2020-2-1072)“IDH突变伴MGMT甲基化和/或1p/19q缺失低级别胶质瘤低量放射治疗联合替莫唑胺化疗的有效性和安全性研究”。

摘　　要：目的:基于ArcCheck和电子射野影像装置(EPID)开展脑瘤患者特异性容积调强放射治疗(VMAT)剂量验证,明确两种不同类别验证工具对脑瘤VMAT剂量验证的适用性,探索剂量验证中γ通过率容差限值(TL)和干预限值(AL),为放射治疗质量控制提供参考。方法:采用随机数表法选取在医院实施VMAT计划的180例脑瘤患者。根据病种及部位的不同将其分为30例较大靶区胶质瘤计划(X方向≥14 cm)、30例中等靶区胶质瘤计划(X方向<14 cm)、30例较小靶区室管膜瘤计划、30例生殖细胞瘤全脑计划、30例生殖细胞瘤全脑室计划、60例生殖细胞瘤小野加量计划和30例脑膜瘤计划,分别基于ArcCheck和EPID开展剂量验证,并将其分为ArcCheck组和EPID组;γ分析均设置为3%/2 mm标准、10%剂量阈值下γ通过率≥95%;对比两组验证计划γ通过率,评价剂量验证的TL和AL。结果:(1)靶区较大胶质瘤和全脑计划中ArcCheck组γ通过率分别为98.40%和98.90%,均高于EPID组,其差异有统计学意义(Z=-4.423,Z=-4.685;P<0.05),ArcCheck组TL、AL明显高于通用限值,EPID组TL、AL较通用限值差近5%;(2)靶区中等胶质瘤和全脑室计划中ArcCheck组和EPID组γ通过率分别为96.98%、97.36%和97.11%、97.60%,两组γ通过率差异无统计学意义,两组TL和AL均≥94%和>90%;(3)小靶区的室管膜瘤计划和生殖细胞瘤小野加量计划,ArcCheck组γ通过率分别为93.45%和94.06%,均低于EPID组,其差异有统计学意义(t=-9.40%,t=-9.41;P<0.05),ArcCheck组TL较通用限值差分别为6.88%和8.47%,AL较通用限值差分别为10.40%和8.76%,EPID组TL>90%、AL接近90%;(4)靶区大小不一、形状复杂的脑膜瘤中ArcCheck组和EPID组γ通过率分别为96.75%和97.05%,差异均无统计学意义,ArcCheck组TL、AL分别为89.33%和86.86%;EPID组TL、AL分别为93.17%和89.69%,更接近通用限值。结论:在靶区较大胶质瘤和全脑VMAT计划中,推荐使用ArcCheck进行剂量验证。在靶区较小室管膜瘤�Objective:To carry out the dose verification of specific volumetric modulated arc therapy(VMAT)for patients with brain tumor based on ArcCheck and electronic portal imaging devices(EPID),and to pinpoint the applicability of the two different kinds of verification tools for the VMAT dose verification for brain tumor,and to explore the tolerance limits(TL)and action limits(AL)of γ pass rate in dose verification,so as to provide reference for quality control of radiotherapy.Methods:A random number table method was used to select 180 patients with brain tumors who underwent the VMAT plans in the hospital.According to the disease type and location,the plans of these patients were divided into 30 cases with larger target region of glioma plan(x direction≥14 cm),30 cases with medium-target region of glioma plan(x<14 cm),30 cases with smaller target region of ependymoma plan,30 cases with germinoma of whole brain plan,30 cases with germinoma of whole ventricle plan,60 cases with germinoma of small field dosage plan and 30 cases with meningioma plan.Dose verifications based on ArcCheck and EPID were respectively performed for all plans,and they were divided into ArcCheck group and EPID group,and γ analyses were set as 3%/2mm standard and γ pass rate≥95% under 10% dose threshold value.The γ pass rates of two groups of verification plans were compared,and the TL and AL of dose verification were further evaluated.Results:1The γ pass rates of ArcCheck group in the larger target region of glioma plan and whole brain plan were respectively 98.40% and 98.90%,which were significantly higher than those of EPID group(Z=-4.423,Z=-4.685,P<0.05).The TL and AL of ArcCheck group were obviously higher than the general limits,and the TL and AL of the EPID group were nearly 5% worse than the general limits.2The γ pass rates of ArcCheck group and EPID group in medium-target region of glioma plan and whole ventricle plan were respectively 96.98%/97.36% and 97.11%/97.60%,and the differences of them between two groups were respective

关 键 词：脑瘤 剂量验证 容积调强放射治疗(VMAT) 容差限值(TL) 干预限值(AL) 

分 类 号：R816.1[医药卫生—放射医学]