Zhang Junyu, Lu Yan, Sheng Yinxiangzi, Wang Weiwei, Hong Zhengshan, Sun Yun, Zhou Rong, Cheng Jingyi
Department of Nuclear Medicine, Shanghai Proton and Heavy Ion Center, Fudan University Cancer Hospital, Shanghai, China.
Shanghai Key Laboratory of Radiation Oncology, Shanghai, China.
Front Oncol. 2021 Sep 3;11:617787. doi: 10.3389/fonc.2021.617787. eCollection 2021.
Positron emission tomography (PET) range verification is an important method that can help improve the confidence in proton therapy for clinical applications. Two kinds of verification methods are implemented and compared based on clinical cases in this study.
The study is conducted on 14 breast cancer patients following proton irradiation treatment. Verification is done by calculating the depth error between the numerically predicted values with the measured PET image along the beam direction. Point-based and segment-based methods are applied and compared. The verification results are presented as depth error means and standard deviations in a region of interest (ROI).
The mean value of the depth error of all 14 cases is within the range of [-3, 3] mm for both point-based and segment-based methods, and only one case result calculated by the point-based method is slightly beyond -3 mm. When comparing the mean depth error from the two methods, the paired -test result shows that the -value is 0.541, and the standard deviation of the segment-based method is smaller than that of the point-based method.
In breast cancer case verification application, point-based and segment-based methods show no significant difference in the mean value of results. Both methods can quantify the accuracy of proton radiotherapy to the millimeter level.
正电子发射断层扫描（PET）射程验证是一种重要方法，有助于提高质子治疗临床应用的可信度。本研究基于临床病例实施并比较了两种验证方法。
对14例接受质子照射治疗后的乳腺癌患者进行研究。通过计算沿射束方向测量的PET图像与数值预测值之间的深度误差来进行验证。应用并比较了基于点和基于段的方法。验证结果以感兴趣区域（ROI）内的深度误差均值和标准差表示。
基于点和基于段的方法，所有14例病例的深度误差均值均在[-3, 3]mm范围内，基于点的方法计算的只有1例结果略超出-3mm。比较两种方法的平均深度误差时，配对检验结果显示，P值为0.541，基于段的方法的标准差小于基于点的方法。
在乳腺癌病例验证应用中，基于点和基于段的方法在结果均值上无显著差异。两种方法都能将质子放疗的准确性量化到毫米级别。
