摘要:
Objective To evaluate the clinical application of Catalyst system in positioning patients during cervical cancer radiotherapy,and to analyze its correlation with the bladder volume and body mass index (BMI) of patients.Methods A total of 33 patients diagnosed with cervical cancer from July to December 2017 in our hospital were included in the study.All patients were auxiliary positioned by an optical surface imaging system (C-Pad Catalyst) before each treatment.The CBCT imaging was executed twice a week.The setup errors from Catalyst and CBCT in the anterior-posterior (AP),superior-inferior (SI) and leg-fight (LR) directions were recorded.Each patient's bladder volume and BMI were also recorded.Results The setup errors between Catalyst with masks and CBCT had the significant difference in SI (P<0.05) and LR (P<0.05).For Catalyst without masks,the setup errors with the bladder volume of 200-300 ml had the significant association in SI (R=-0.316,P<0.05).For the bladder volume of>300 ml,the setup errors for Catalyst with masks had the significant association in AP (R=-0.493,P<0.05),and that without masks had the significant association in SI and LR (R=0.335,P<0.05,R=-0.348,P<0.05).For patients of<25 kg/m2,setup errors for Catalyst with masks had the significant association with the BMI in LR (R=0.197,P<0.05);for ≥ 25 kg/m2,that with masks had the significant association in AP and SI (R =0.818,P<0.05;R=-0.498,P<0.05),that without masks had the significant association in AP and LR (R=0.652,P<0.05;R=-0.558,P<0.05).Conclusion Unlike CBCT system,the patient positioning by Catalyst system was easily affected by the bladder volume and BMI of patients.%目的 评估Catalyst在宫颈癌患者放疗摆位中的应用,并分析其与膀胱容积(BV)、体质量指数(BMI)的相关性.方法 2017年7-12月收治的33例宫颈癌患者,首次治疗时常规摆位(室内激光+体膜标记)后进行CBCT验证,再利用Catalyst分别获取有膜与无膜时患者影像,并将其作为参考影像;非首次时常规摆位后利用Catalyst辅助摆位,并进行每周2次CBCT验证.记录BV和BMI,以及两系统在腹背(AP)、头脚(SI)、左右(LR)的摆位误差.结果 两系统摆位误差在SI和LR方向不同,Catalyst较CBCT受BV和BMI影响显著(P<0.05).BV在200~ 300 ml时,Catalyst无膜误差与BV在SI方向R值为-0.316(P<0.05);BV>300ml时,有膜误差与BV在AP方向R值为-0.493(P<0.05),无膜误差与BV在SI、LR方向R值分别为0.335 (P<0.05)、-0.348(P<0.05).BMI<25kg/m2时Catalyst有膜误差与BMI在LR方向R值为0.197(P<0.05),≥25 kg/m2时AP、SI方向R值分别为0.818(P<0.05)、-0.498(P<0.05);无膜误差在BMI≥25 kg/m2时与BMI在AP、LR方向R值分别为0.652(P<0.05)、-0.558(P<0.05).结论 Catalyst与CBCT相比摆位误差在SI、LR有显著差异,基于Catalyst的摆位易受宫颈癌患者BV与BMI的影响.