From University Medical Imaging Toronto, Joint Department of Medical Imaging, University Health Network, Mount Sinai Hospital and Women's College Hospital, Princess Margaret Cancer Centre, 610 University Ave, Suite 3-920, Toronto, ON, Canada M5G 2M9 (V.M., U.M.); Department of Medical Imaging (V.M., U.M.), Department of Radiation Oncology (R.M.G., A.B., M.R.), and TECHNA Institute, University Health Network (A.B., U.M.), University of Toronto, Toronto, Canada; and Radiation Medicine Program (R.M.G., A.B.) and Department of Biostatistics (A.S.), Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.
Radiology. 2023 Dec;309(3):e231407. doi: 10.1148/radiol.231407.
Background Prostate-specific membrane antigen (PSMA) PET is useful in the early detection of oligorecurrent prostate cancer (PCa), but whether PSMA PET parameters can be used to identify patients who would benefit from metastasis-directed therapy (MDT) with radiation or surgery remains uncertain. Purpose To assess the association of PSMA PET parameters with outcomes of patients with oligorecurrent PCa after MDT. Materials and Methods In this retrospective analysis of a single-center phase II trial that enrolled patients with biochemical recurrence of PCa after maximal local therapy and with no evidence of disease at conventional imaging, patients underwent PSMA PET (between May 2017 and November 2021), and unveiled recurrences were treated with MDT. Maximum standardized uptake value (SUV) and mean standardized uptake value (SUV) and PSMA tumor volume derived using thresholds of 2.5 (SUV) and 41% (SUV), respectively, were recorded for sites of recurrence on PSMA PET scans, and a molecular imaging PSMA score was assigned. These parameters were also corrected for smooth filter and partial volume effects, and the PSMA score was reassigned. Cox proportional hazards models were used to evaluate the relationship between PSMA PET parameters and outcomes. Results A total of 74 men (mean age, 68.3 years ± 6.6 [SD]) with biochemical recurrence of PCa were included. PSMA PET revealed 145 lesions in the entire cohort, of which 125 (86%) were metastatic lymph nodes. Application of the correction factor changed the PSMA score in 88 of 145 lesions (61%). Mean SUV, SUV, and SUV were associated with lower risk of biochemical progression (hazard ratio [HR] range, 0.77-0.95; 95% CI: 0.61, 1.00; = .03 to = .04). For corrected parameters, mean SUV, mean SUV, mean SUV, mean PSMA score, maximum SUV, maximum SUV, and maximum PSMA score were associated with a lower risk of biochemical progression (HR, 0.61-0.98; 95% CI: 0.39, 1.00; = .01 to = .04). Conclusion Measured and corrected PSMA PET parameters were associated with biochemical progression in men with oligorecurrent PCa treated with MDT. Clinical trial registration no. NCT03160794 © RSNA, 2023 See also the editorial by Civelek in this issue.
背景 前列腺特异性膜抗原 (PSMA) PET 对寡复发前列腺癌 (PCa) 的早期检测很有用，但 PSMA PET 参数是否可用于识别接受放疗或手术的转移导向治疗 (MDT) 获益的患者仍不确定。目的 评估 PSMA PET 参数与寡复发 PCa 患者 MDT 后结局的相关性。材料与方法 这是一项单中心 II 期回顾性分析，纳入了最大局部治疗后生化复发且常规影像学无疾病证据的 PCa 患者，患者接受 PSMA PET（2017 年 5 月至 2021 年 11 月），揭示复发后接受 MDT 治疗。记录 PSMA PET 扫描上复发部位的最大标准化摄取值 (SUV) 和平均标准化摄取值 (SUV) 以及分别使用 2.5（SUV）和 41%（SUV）阈值得出的 PSMA 肿瘤体积，并分配分子成像 PSMA 评分。还对这些参数进行了平滑滤波和部分容积效应校正，并重新分配 PSMA 评分。使用 Cox 比例风险模型评估 PSMA PET 参数与结局之间的关系。结果 共纳入 74 例（平均年龄 68.3 岁±6.6[标准差]）生化复发的 PCa 男性患者。PSMA PET 在整个队列中发现 145 个病灶，其中 125 个（86%）为转移性淋巴结。校正因子的应用改变了 145 个病灶中的 88 个（61%）的 PSMA 评分。平均 SUV、SUV 和 SUV 与生化进展风险降低相关（风险比 [HR] 范围，0.77-0.95；95%CI：0.61，1.00； =.03 至 =.04）。对于校正后的参数，平均 SUV、平均 SUV、平均 SUV、平均 PSMA 评分、最大 SUV、最大 SUV 和最大 PSMA 评分与生化进展风险降低相关（HR，0.61-0.98；95%CI：0.39，1.00； =.01 至 =.04）。结论 在接受 MDT 治疗的寡复发 PCa 男性中，测量和校正后的 PSMA PET 参数与生化进展相关。临床试验注册号 NCT03160794 ©RSNA，2023 也可参见本期杂志 Civelek 的社论。
