中山大学学报（医学科学版）2012，Vol.33Issue(5)：678-682,5.
应用锥形束CT研究鼻咽癌容积弧形调强放射治疗的摆位误差
Analysis of Inter-fraction and Intra-fraction Setup Error of Nasopharyngeal Carcinoma Patients Treated with Volumetric Modulated Arc Therapy (VMAT) with Cone Beam CT
摘要
Abstract
[Objective] To evaluate the inter-fraction and intra-fraction setup error during the treatment with cone beam computer tomography (CBCT) and provide theoretical basis for clinical target volume-planning target volume (CTV-PTV) margins for nasopharyngeal carcinoma patients treated with volumetric-modulated arc: therapy (VMAT). [Methods] Seventeen consecutive NPC patients treated with VMAT were prospectively enrolled for the study between October 2010 and January 2012. For each patient, three CBCT scans were obtained after conventional positioning, online correction with 2 mm tolerance daily and VMAT delivery weekly, and the scans were registered to the planning CT to determine inter-fraction and intra-fraction errors. The MPTV were calculated with the recipe, Vmurin = 2.5Σ + 0.7σ (Σ, systematic error; σ, random error). [Results] The average absolute errors of the pre-correction, post-correction, and intra-fraction error were 1.1-1.2 mm, 0.6-0.7 mm and 0.4-0.6 mm in the three dimensions. The corresponding X were 0.9—1.3 mm, 0.4—0.5 mm and 0.2-0.4 mm, σ were 0.7-0.9 mm, 0.7 mm and 0.5-0.7 mm. Gradual increases in both inter-fraction and intra-fraction three-dimensional (3D) displacement were observed with time and treatment (P = 0.004, P = 0.009). The total MPTV accounting for pre-correction and intra-fraction error were 3.4-4.0 mm and margins accounting for post-correction and intra-fraction error were 1.7—2.3 mm. [Conclusions] VMAT irradiation technology personalized MPTV should be adopted for the design of VMAT plan. Displacement increased as a function of time.关键词
锥形束断层扫描/摆位误差/计划靶区/鼻咽癌/容积旋转放射治疗Key words
cone-beam computed tomography/ setup error/ planning target volume/ nasopharyngeal carcinoma/ volumetric modulated arc therapy分类
医药卫生引用本文复制引用
尹文晶,孙颖,迟峰,方键蓝,郭蕊,林爱华,祁振宇,马骏..应用锥形束CT研究鼻咽癌容积弧形调强放射治疗的摆位误差[J].中山大学学报（医学科学版）,2012,33(5):678-682,5.基金项目
国家自然科学基金(81071835) （81071835）
卫生部临床学科重点项目(2010178) （2010178）
广东省科技计划项目(2009B030801016) （2009B030801016）
珠江学者(2010) （2010）
