光学表面成像系统SRS算法在非共面放疗中的技术性能评估  

Evaluation of technical performance of stereotactic radiosurgery algorithm in optical surface imaging system in non-coplanar radiotherapy

作　　者：刘首鹏 陈洪佳 赖佳路 毛尔布 周楫 黄洋 刘登洪 钟仁明[2] Liu Shoupeng;Chen Hongjia;Lai Jialu;Mao Erbu;Zhou Ji;Huang Yang;Liu Denghong;Zhong Renming(Department of Oncology,Fifth People's Hospital of Chengdu,Chengdu 611130,China;Radiotherapy Physics&Technology Center,Cancer Center,West China Hospital,Sichuan University,Chengdu 610041,China;Qilu Medical University,Zibo 255300,China)

机构地区：[1]成都市第五人民医院肿瘤科,成都611130 [2]四川大学华西医院肿瘤中心放射物理技术中心,成都610041 [3]齐鲁医药学院,淄博255300

出　　处：《中华放射肿瘤学杂志》2023年第5期438-444,共7页Chinese Journal of Radiation Oncology

基　　金：四川省科技厅项目(2021YFQ0065);四川大学华西医院临床研究孵化项目(2021HXFH029)。

摘　　要：目的评估光学表面成像(OSI)系统立体定向放射外科(SRS)算法在非共面放疗中的精确性和稳定性。方法在治疗床不同公转角度下使用三套OSI系统对模体重复测量,分析OSI对模体成像的精确性和稳定性。随机选取7例行单中心非共面放疗的多发脑转移瘤患者,分析OSI用于患者成像的精确性和稳定性。稳定性定义为以0°锥形线束CT(CBCT)为“金标准”,治疗床从0°转到非零角度,再转回0°时,前后两次OSI测量的差值。精确性定义为OSI与CBCT(治疗床0°时)测量数据的差异。符合正态分布的计量资料以x¯±s描述,不符合正态分布采用M(Q)方式描述;前者差异比较用单因素方差分析,后者用Kruskal-Wallis H非参数检验分析。结果对于非共面,模体和患者的平移精度分别为≤1.30 mm和≤1.00 mm,旋转精度分别为≤0.50°和≤0.60°,平移误差均主要出现在左右和头脚方向。在稳定性方面,模体平移和旋转的最大标准差分别为0.06 mm和0.06°,患者平移和旋转的最大标准差分别为0.17 mm和0.19°。结论新型SRS算法虽对非共面的精度有所改善,但仍不能满足颅内多靶点单中心非共面放疗的精确要求,特别是在左右和头脚方向。对于非共面角度较大时,不建议将其用于图像引导,但其稳定性高可用于监测患者的分次内运动。Objective To evaluate the accuracy and stability of stereotactic radiosurgery(SRS)algorithm in optical surface imaging(OSI)system in non-coplanar radiotherapy.Methods Three OSI imaging systems were used to measure the phantom repeatedly at different couch rotation angles to analyze the accuracy and stability of OSI system.Seven patients with multiple brain metastases who underwent single-center non-coplanar radiotherapy were randomly selected,and the accuracy and stability of OSI for patient imaging were analyzed.Stability is defined as the difference between the two OSI measurements when the couch is turned from 0°to a non 0°angle,and then back to 0°,using the 0°cone beam CT(CBCT)as the"gold standard".Accuracy is defined as the difference between OSI and CBCT(at 0°couch angle)measurement data.The measurement data with normal distribution were described as Mean±SD.The data with non-normal distribution were expressed as M(Q).The difference of the former data was compared by one-way ANOVA,and the difference of the latter data was assessed by Kruskal-Wallis H nonparametric test.Results For non-coplanarity,the translation accuracy of the phantom and the patient was≤1.30 mm and≤1.00 mm,and the rotation accuracy was≤0.50°and≤0.60°,respectively.The translation errors mainly occurred in the left-right and head-foot directions.In terms of stability,the maximum standard deviation of phantom coplanar translation and rotation was 0.06 mm and 0.06°.The maximum standard deviation of patient translation and rotation was 0.17 mm and 0.19°.Conclusions Although the new SRS algorithm improves the non-coplanar accuracy,it still cannot meet the precise requirements of non-coplanar single isocenter radiotherapy for multiple brain metastases,especially in the left-right and head-foot directions.When the couch rotation angle is large,OSI is not recommended for image-guided radiotherapy.However,its high stability can be used to monitor the intrafractional motion of patients.

关 键 词：光学表面成像系统 放射疗法 非共面 多发脑转移瘤 立体定向放射外科算法 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术] R815[自动化与计算机技术—计算机科学与技术]