Synergy加速器治疗床自动摆位准确性的验证

摘要

目的:验证图像引导放射治疗中Synergy加速器治疗床位置自动校正(RATM)的准确性.方法:Quasar Penta-Guide模体在Brilliance下进行定位扫描,CT图像传送到PrecisePlan治疗计划系统进行计划设计,计划分别传至MOSAIQ和XVI系统.模体在加速器治疗床上摆位后进行CBCT扫描,图像配准后用RATM进行治疗床自动位置校正,用直尺测量激光灯十字线和模体中心十字线的距离作为摆位偏差.选取头部肿瘤患者,CBCT扫描后用骨性标记自动配准,移床后再做一次CBCT扫描,配准后分析残存摆位误差.结果:治疗床的自动最大校正范围为20 mm.模体验证结果显示,在左右、头脚、垂直3个方向自动校正误差均小于2mm.头部肿瘤患者的残存误差小于2mm.结论:治疗床远程控制自动摆位的准确性满足临床要求,治疗床自动移动的准确性直接影响治疗效果,需要对治疗床移动的准确性进行验证和采取严格的质量保证措施.%To verify the positioning accuracy of remote automatic table movement (RATM) equipped with Synergy accelerator. Methods: Quasar Penta-Guide phantom was scanned with Brilliance, and the CT images were transferred to Pre-cisePlan 2.16. A treatment plan was made and transferred to MOSAIQ database and XVI units. The Penta-Guide was placed on the treatment table and aligned with the laser. CBCT images were acquired and matched in grey scale mode to the planning CT. Setup errors were corrected with RATM. Distances between laser and phantom crosswires were measured. Patients with brain tumors were selected to perform patient-specific verification. After the table correction with RATM, another CBCT scan was completed and the residual setup error was obtained through automatic bone match. Results: The maximum table correction range was 20 mm. The phantom verification showed that the table movement errors were all less than 2 mm in lateral, vertical and longitudinal directions. Residual setup errors were less than 2 mm for patient specific cases. Conclusions: RATM has the required accuracy for treatment. Quality assurance and control must be taken seriously because the positioning accuracy for remote automatic table movement plays an important influent in curative effect