Smith Christopher W, Alfano Ryan, Hoover Douglas, Surry Kathleen, D'Souza David, Thiessen Jonathan, Rachinsky Irina, Butler John, Gomez Jose A, Gaed Mena, Moussa Madeleine, Chin Joseph, Pautler Stephen, Bauman Glenn S, Ward Aaron D
Baines Imaging Research Laboratory, 790 Commissioners Rd E, London, ON N6A 5W9, Canada.
Lawson Health Research Institute, 750 Base Line Rd E, London, ON N6C 2R5, Canada.
Phys Imaging Radiat Oncol. 2021 Jul 30;19:102-107. doi: 10.1016/j.phro.2021.07.001. eCollection 2021 Jul.
Prostate specific membrane antigen positron emission tomography imaging (PSMA-PET) has demonstrated potential for intra-prostatic lesion localization. We leveraged our existing database of co-registered PSMA-PET imaging with cross sectional digitized pathology to model dose coverage of histologically-defined prostate cancer when tailoring brachytherapy dose escalation based on PSMA-PET imaging.
Using a previously-developed automated approach, we created segmentation volumes delineating underlying dominant intraprostatic lesions for ten men with co-registered pathology-imaging datasets. To simulate realistic high-dose-rate brachytherapy (HDR-BT) treatments, we registered the PSMA-PET-defined segmentation volumes and underlying cancer to 3D trans-rectal ultrasound images of HDR-BT cases where 15 Gray (Gy) was delivered. We applied dose/volume optimization to focally target the dominant intraprostatic lesion identified on PSMA-PET. We then compared histopathology dose for all high-grade cancer within whole-gland treatment plans versus PSMA-PET-targeted plans. Histopathology dose was analyzed for all clinically significant cancer with a Gleason score of 7or greater.
The standard whole-gland plans achieved a median [interquartile range] D98 of 15.2 [13.8-16.4] Gy to the histologically-defined cancer, while the targeted plans achieved a significantly higher D98 of 16.5 [15.0-19.0] Gy (p = 0.007).
This study is the first to use digital histology to confirm the effectiveness of PSMA-PET HDR-BT dose escalation using automatically generated contours. Based on the findings of this study, PSMA-PET lesion dose escalation can lead to increased dose to the ground truth histologically defined cancer.
前列腺特异性膜抗原正电子发射断层扫描成像（PSMA-PET）已显示出在前列腺内病变定位方面的潜力。我们利用现有的PSMA-PET成像与横断面数字化病理共同注册的数据库，在基于PSMA-PET成像调整近距离放射治疗剂量递增时，对组织学定义的前列腺癌的剂量覆盖情况进行建模。
我们采用先前开发的自动化方法，为10名拥有病理-影像数据集共同注册的男性创建了分割体积，以描绘潜在的主要前列腺内病变。为了模拟现实的高剂量率近距离放射治疗（HDR-BT）治疗，我们将PSMA-PET定义的分割体积和潜在癌症与已给予15格雷（Gy）剂量的HDR-BT病例的三维经直肠超声图像进行配准。我们应用剂量/体积优化来聚焦靶向PSMA-PET上识别出的主要前列腺内病变。然后，我们比较了全腺治疗计划中所有高级别癌症的组织病理学剂量与PSMA-PET靶向计划的剂量。对所有Gleason评分为7或更高的具有临床意义的癌症进行了组织病理学剂量分析。
标准的全腺计划对组织学定义的癌症的D98中位数[四分位间距]为15.2[13.8 - 16.4]Gy，而靶向计划的D98显著更高，为16.5[15.0 - 19.0]Gy（p = 0.007）。
本研究首次使用数字组织学来证实使用自动生成轮廓进行PSMA-PET HDR-BT剂量递增的有效性。基于本研究的结果，PSMA-PET病变剂量递增可导致对组织学定义的实际癌症的剂量增加。
