Hrinivich William Thomas, Hoover Douglas A, Surry Kathleen, Edirisinghe Chandima, Velker Vikram, Bauman Glenn, D'Souza David, Fenster Aaron, Wong Eugene
Department of Medical Biophysics, Western University, London, ON, Canada; Robarts Imaging Research Lab, Western University, London, ON, Canada.
Department of Medical Biophysics, Western University, London, ON, Canada; Department of Oncology, Western University, London, ON, Canada; London Regional Cancer Program, London, ON, Canada.
Brachytherapy. 2017 Sep-Oct;16(5):1035-1043. doi: 10.1016/j.brachy.2017.06.008. Epub 2017 Jul 29.
To measure the accuracy and variability of manual high-dose-rate (HDR) prostate brachytherapy (BT) needle tip localization using sagittally reconstructed three-dimensional (3D) transrectal ultrasound (TRUS) augmented with live two-dimensional (2D) sagittal TRUS.
Ten prostate cancer patients underwent HDR-BT during which the sagittally assisted sagittally reconstructed (SASR) segmentation technique was completed in parallel with commercially available sagittally assisted axially reconstructed (SAAR) TRUS for comparison. The SASR technique makes use of live 2D ultrasound intraoperatively and allows needle tip updates using the final 3D image in the absence of image artifacts. These updates were repeated offline twice by two separate users. Needle end-length measurements were used to calculate insertion depth errors (IDEs) for each technique.
Images of 147 needles were analyzed. For the SASR technique, both users were confident in tip positions on the final 3D image within 3 mm for 52% of needles, so these tip positions were updated. For the remaining 48% of needles, the tip positions from the live 2D images were used. This SASR technique enabled the localization of all needles with IDEs within ±3 mm for 84% of needles and IDE range of [-6.2 mm, 5.9 mm], compared with 57% and [-8.1 mm, 7.7 mm] when using the commercially available SAAR technique.
The SASR technique mitigates the impact of 3D TRUS image artifacts on HDR-BT needle tip localization by incorporating live 2D sagittal TRUS intraoperatively and provides a statistically significant reduction in IDE variance compared with the routine SAAR technique.
使用矢状面重建的三维（3D）经直肠超声（TRUS）结合实时二维（2D）矢状面TRUS，测量手动高剂量率（HDR）前列腺近距离放射治疗（BT）针尖端定位的准确性和可变性。
10例前列腺癌患者接受了HDR-BT治疗，在此过程中，并行完成矢状面辅助矢状面重建（SASR）分割技术与市售的矢状面辅助轴向重建（SAAR）TRUS进行比较。SASR技术在术中使用实时2D超声，并允许在没有图像伪影的情况下使用最终3D图像更新针尖端位置。两名不同的用户在离线状态下将这些更新重复了两次。使用针的末端长度测量值来计算每种技术的插入深度误差（IDE）。
分析了147根针的图像。对于SASR技术，两名用户对最终3D图像上52%的针的尖端位置在3毫米内有信心，因此更新了这些尖端位置。对于其余48%的针，使用实时2D图像的尖端位置。这种SASR技术能够将84%的针的所有针尖端定位在±3毫米的IDE范围内，IDE范围为[-6.2毫米，5.9毫米]，而使用市售SAAR技术时分别为（定位在±3毫米的IDE范围内的针的比例）57%和IDE范围[-8.1毫米，7.7毫米]。
SASR技术通过术中结合实时2D矢状面TRUS减轻了3D TRUS图像伪影对HDR-BT针尖端定位的影响，并且与常规SAAR技术相比，在IDE方差方面有统计学上的显著降低。
