红外定位系统在前列腺癌放射治疗的摆位和验证中的应用

摘要

目的 探讨红外定位系统(OPS)能否实现对前列腺癌放射治疗日常摆位的监控和校准.方法 选取20例前列腺癌患者,随机分为两组,实验组使用OPS和常规验证方法 ,对照组仅使用常规验证方法 .患者通过千伏级锥形束CT(CBCT)采集图像信息,得到肿瘤放疗靶位图像,将验证图像与计划图像匹配得到X(左右方向)、Y(头脚方向)、Z(前后方向)3个方向的误差.比较两组数据,并记录急性放射不良反应情况.结果 实验组在X、Y、Z 3个方向上的摆位误差分别(1.1±0.9)mm、(2.9±1.2)mm、(1.1±0.8)mm,小于对照组的(2.2±1.3) mm、(6.4±2.3) mm、(2.8±1.5) mm,差异有统计学意义(P＜0.05).实验组发生≥1级急性直肠黏膜反应和泌尿系统反应的比例分别为40.0％(4/10)、30.0％(3/10),明显低于对照组的70.0％(7/10)、60.0％(6/10).实验组在X、Y、Z、3个方向上的计划靶区(PTV)外放值(MPTV)分别为4.3mm、5.3mm、3.9mm;对照组在X、Y、Z3个方向上MPTV值分别为6.1 mm、9.1 mm、6.4mm.结论 在放射治疗摆位中引入红外定位小球可提高摆位精确度,减小摆位误差,从而提高前列腺癌患者放射治疗精度,提高临床疗效.%Objective To explore whether the infrared positioning system (OPS) can be used to monitor and calibrate the daily placement of radiotherapy for prostate cancer. Methods Twenty patients with prostate cancer were divided into two groups. OPS was used in the experimental group, and OPS was not used in the control group. The images of the radiotherapy target were obtained by kilovoltage cone-beam computed tomography (CBCT), and the error of X (left-right), Y (superior-inferior) and Z (anterior-posterior) were obtained by matching the image with the planned image. Then the data of two groups were compared, and acute radiation adverse reactions were recorded. Results The set-up errors in the three directions of X, Y and Z in the experimental group were (1.1±0.9) mm, (2.9±1.2) mm, and (1.1±0.8) mm, respectively, which were smaller than mm, (6.4±2.3) mm, (2.8±1.5) mm in the control group, and the difference was statistically significant (P＜0.05). The proportion of grade acute intestinal mucosal reaction and urinary system reaction in the experimental group was 40.0％ (4/10) and 30.0％ (3/10), respectively, which was significantly less than 70.0％ (7/10) and 60.0％ (6/10) in the control group. The values of PTV margin (MPTV) of the experimental group in X, Y and Z were 4.3 mm, 5.3 mm and 3.9 mm, respectively. The MPTV values of the control group in X, Y and Z were 6.1 mm, 9.1 mm and 6.4 mm, respectively. Conclusion The introduction of infrared fixed ball can increase the accuracy of placement and reduce the placement error in radiotherapy, so as to improve the accuracy of radiotherapy for prostate cancer patients and improve the clinical efficacy of radiotherapy.