Baines Imaging Research Laboratory, London, Ontario, Canada; Lawson Health Research Institute, London, Ontario, Canada; Department of Medical Biophysics, Western University, London, Ontario, Canada; London Regional Cancer Program, London, Ontario, Canada.
Lawson Health Research Institute, London, Ontario, Canada; Department of Medical Biophysics, Western University, London, Ontario, Canada; London Regional Cancer Program, London, Ontario, Canada.
Brachytherapy. 2021 May-Jun;20(3):601-610. doi: 10.1016/j.brachy.2021.01.005. Epub 2021 Feb 26.
Using multiparametric MRI data and the pathologic data from radical prostatectomy specimens, we simulated the treatment planning of dose-escalated high-dose-rate brachytherapy (HDR-BT) to the Multiparametric MRI dominant intraprostatic lesion (mpMRI-DIL) to compare the dose potentially delivered to the pathologically confirmed locations of the high-grade component of the cancer.
Pathologist-annotated prostatectomy midgland histology sections from 12 patients were registered to preprostatectomy mpMRI scans that were interpreted by four radiologists. To simulate realistic HDR-BT, we registered each observer's mpMRI-DILs and corresponding histology to two transrectal ultrasound images of other HDR-BT patients with a 15-Gy whole-gland prescription. We used clinical inverse planning to escalate the mpMRI-DILs to 20.25 Gy. We compared the dose that the histopathology would have received if treated with standard treatment plans to the dose mpMRI-targeting would have achieved. The histopathology was grouped as high-grade cancer (any Gleason Grade 4 or 5) and low-grade cancer (only Gleason Grade 3).
212 mpMRI-targeted HDR-BT plans were analyzed. For high-grade histology, the mpMRI-targeted plans achieved significantly higher median [IQR] D98 and D90 values of 18.2 [16.7-19.5] Gy and 19.4 [17.8-20.9] Gy, respectively, in comparison with the standard plans (p = 0.01 and p = 0.003). For low-grade histology, the targeted treatment plans would have resulted in a significantly higher median D90 of 17.0 [16.1-18.4] Gy in comparison with standard plans (p = 0.015); the median D98 was not significantly higher (p = 0.2).
In this retrospective pilot study of 12 patients, mpMRI-based dose escalation led to increased dose to high-grade, but not low-grade, cancer. In our data set, different observers and mpMRI sequences had no substantial effect on dose to histologic cancer.
利用多参数 MRI 数据和根治性前列腺切除术标本的病理数据，我们模拟了针对多参数 MRI 优势前列腺内病变（mpMRI-DIL）的调强高剂量率近距离治疗（HDR-BT）的治疗计划，以比较潜在的治疗剂量与癌症高级别成分的病理确认位置。
对 12 例患者的前列腺中叶病理标本进行了病理学家注释，并将其与 4 位放射科医生的术前 mpMRI 扫描进行了配准。为了模拟真实的 HDR-BT，我们将每位观察者的 mpMRI-DIL 及其相应的组织学与另外 2 例接受 15 Gy 全腺体处方的 HDR-BT 患者的 2 个经直肠超声图像进行了配准。我们使用临床反规划将 mpMRI-DIL 上调至 20.25 Gy。我们比较了如果采用标准治疗计划治疗，组织病理学将接受的剂量与 mpMRI 靶向治疗将达到的剂量。组织病理学分为高级别癌症（任何 Gleason 分级 4 或 5）和低级别癌症（仅 Gleason 分级 3）。
分析了 212 例 mpMRI 靶向 HDR-BT 计划。对于高级别组织学，mpMRI 靶向计划的 D98 和 D90 值中位数[四分位距]分别显著更高，分别为 18.2[16.7-19.5]Gy 和 19.4[17.8-20.9]Gy，与标准计划相比（p=0.01 和 p=0.003）。对于低级别组织学，与标准计划相比，靶向治疗计划会导致 D90 中位数显著更高，为 17.0[16.1-18.4]Gy（p=0.015）；D98 中位数没有显著更高（p=0.2）。
在这项对 12 例患者的回顾性试点研究中，mpMRI 引导的剂量升级导致高级别癌症的剂量增加，但不会导致低级别癌症的剂量增加。在我们的数据集中，不同的观察者和 mpMRI 序列对组织学癌症的剂量没有实质性影响。
