基于不同呼吸方式对左侧乳腺癌放疗摆位误差分析

Displacement Error Analysis of Left Breast Cancer Radiotherapy Based on Different Breathing Modes

目的:比较分析光学体表监测系统(OSMS)引导下的深度吸气屏气(DIBH)技术与常规自由呼吸(FB)技术在左侧乳腺癌放疗中的摆位误差。方法:选择2019年8月~2021年8月在复旦大学附属肿瘤医院放射治疗中心治疗的40例左侧乳腺癌患者并分为两组:对照组采用FB技术;观察组采用结合光学体表图像引导放疗(SGRT)的DIBH技术,采集并统计各病例前五次锥形束CT(CBCT)扫描图像配准误差。结果:对40例患者200套CBCT图像分析,对照组患者在左右方向(LAT)、头脚方向(LNG)与腹背方向(VRT)的平均误差分布为>7mm:5%、5%和5%;5~7mm:15%、20%和10%;<5mm:80%、75%和85%;观察组患者各方向的平均误差分布均<5mm。首次验证时,观察组LAT误差小于对照组(P<0.05),LNG与VRT无差异(P>0.05);第二次验证时,观察组LAT与LNG误差均小于对照组(P<0.05),VRT无差异(P>0.05);观察组后三次影像验证时,各方向误差均小于对照组(P<0.05);平均误差比较时,观察组各方向误差均小于对照组(P<0.05);全组首次与后四次影像验证误差比较均无差异(P>0.05),其中观察组误差波动更小。结论:左侧乳腺癌患者在放射治疗中使用深吸气屏气呼吸时误差小,重复性优于自由呼吸,且随着疗程进展仍然持续保持稳定。

Objective: To compare and analyze the positional errors between the optical body surface monitoring systems(OSMS)-guided implementation of the Deep Inspiratory Breath-hold(DIBH) technique and the conventional free-breathing(FB) technique during radio therapy for left-sided breast cancer. Methods: 40 patients with left-sided breast cancer treated at the Radiation Therapy Center of the Cancer Hospital of Fudan University from August 2019 to August 2021 were selected and divided into two groups: control group used the FB technique;experimental group used the DIBH technique combined with optical body surface image-guided radiotherapy(SGRT), and the first five cone-beam CT(CBCT) scan image alignment errors were collected and counted for each case. Results: For the analysis of 200 sets of CBCT images in 40 patients, the mean error distributions in the left-right direction(LAT), head-foot direction(LNG) and ventral-dorsal direction(VRT) in group control group patients were >7mm: 5%, 5% and 5%;5-7mm: 15%, 20% and 10%;<5mm: 80%, 75% and 85%;The mean error distributions in all directions in experimental group patients were <5mm. At the first validation, the LAT errors in experimental group were smaller than that in control group(P<0.05), and there was no difference between LNG and VRT(P>0.05);At the second validation, the LAT and LNG errors in group B were smaller than those in control group(P<0.05), and there was no difference in VRT(P>0.05);At the last three image validations in experimental group the errors in all directions were smaller than those in control group(P<0.05);When the mean errors were compared, the errors in each direction were smaller than that in control group(P<0.05);There was no difference between the first and the last four image verification errors in experimental group(P>0.05). Conclusion: The error of using Deep Inspiratory Breath-hold in radiation therapy for patients with left-sided breast cancer is smaller and more repeatable than free breathing, and it remains stable as the course of treatment progresses.