Department of Radiation Oncology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
German Cancer Consortium (DKTK), Partner Site Freiburg, Freiburg, Germany.
JAMA Netw Open. 2023 May 1;6(5):e2314748. doi: 10.1001/jamanetworkopen.2023.14748.
Prostate-specific antigen membrane positron-emission tomography (PSMA-PET) is increasingly used to guide salvage radiotherapy (sRT) after radical prostatectomy for patients with recurrent or persistent prostate cancer.
To develop and validate a nomogram for prediction of freedom from biochemical failure (FFBF) after PSMA-PET-based sRT.
DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study included 1029 patients with prostate cancer treated between July 1, 2013, and June 30, 2020, at 11 centers from 5 countries. The initial database consisted of 1221 patients. All patients had a PSMA-PET scan prior to sRT. Data were analyzed in November 2022.
Patients with a detectable post-radical prostatectomy prostate-specific antigen (PSA) level treated with sRT to the prostatic fossa with or without additional sRT to pelvic lymphatics or concurrent androgen deprivation therapy (ADT) were eligible.
The FFBF rate was estimated, and a predictive nomogram was generated and validated. Biochemical relapse was defined as a PSA nadir of 0.2 ng/mL after sRT.
In the nomogram creation and validation process, 1029 patients (median age at sRT, 70 years [IQR, 64-74 years]) were included and further divided into a training set (n = 708), internal validation set (n = 271), and external outlier validation set (n = 50). The median follow-up was 32 months (IQR, 21-45 months). Based on the PSMA-PET scan prior to sRT, 437 patients (42.5%) had local recurrences and 313 patients (30.4%) had nodal recurrences. Pelvic lymphatics were electively irradiated for 395 patients (38.4%). All patients received sRT to the prostatic fossa: 103 (10.0%) received a dose of less than 66 Gy, 551 (53.5%) received a dose of 66 to 70 Gy, and 375 (36.5%) received a dose of more than 70 Gy. Androgen deprivation therapy was given to 325 (31.6%) patients. On multivariable Cox proportional hazards regression analysis, pre-sRT PSA level (hazard ratio [HR], 1.80 [95% CI, 1.41-2.31]), International Society of Urological Pathology grade in surgery specimen (grade 5 vs 1+2: HR, 2.39 [95% CI, 1.63-3.50], pT stage (pT3b+pT4 vs pT2: HR, 1.91 [95% CI, 1.39-2.67]), surgical margins (R0 vs R1+R2+Rx: HR, 0.60 [95% CI, 0.48-0.78]), ADT use (HR, 0.49 [95% CI, 0.37-0.65]), sRT dose (>70 vs ≤66 Gy: HR, 0.44 [95% CI, 0.29-0.67]), and nodal recurrence detected on PSMA-PET scans (HR, 1.42 [95% CI, 1.09-1.85]) were associated with FFBF. The mean (SD) nomogram concordance index for FFBF was 0.72 (0.06) for the internal validation cohort and 0.67 (0.11) in the external outlier validation cohort.
This cohort study of patients with prostate cancer presents an internally and externally validated nomogram that estimated individual patient outcomes after PSMA-PET-guided sRT.
前列腺特异性抗原膜正电子发射断层扫描（PSMA-PET）越来越多地用于指导根治性前列腺切除术后复发或持续性前列腺癌患者的挽救性放疗（sRT）。
开发和验证基于 PSMA-PET 的 sRT 后生化无失败（FFBF）的预测列线图。
设计、设置和参与者：这项回顾性队列研究纳入了 2013 年 7 月 1 日至 2020 年 6 月 30 日在 5 个国家的 11 个中心治疗的 1029 例前列腺癌患者。最初的数据库包括 1221 例患者。所有患者在 sRT 前均进行了 PSMA-PET 扫描。数据分析于 2022 年 11 月进行。
接受 sRT 治疗前列腺窝，包括或不包括盆腔淋巴结或同时接受雄激素剥夺治疗（ADT）的有检测到的根治性前列腺切除术后前列腺特异性抗原（PSA）水平的患者有资格接受治疗。
估计了 FFBF 率，并生成和验证了一个预测列线图。生化复发定义为 sRT 后 PSA 最低点<0.2ng/ml。
在列线图创建和验证过程中，纳入了 1029 例患者（sRT 时的中位年龄为 70 岁[IQR，64-74 岁]），并进一步分为训练集（n=708）、内部验证集（n=271）和外部异常值验证集（n=50）。中位随访时间为 32 个月（IQR，21-45 个月）。根据 sRT 前的 PSMA-PET 扫描，437 例（42.5%）患者出现局部复发，313 例（30.4%）患者出现淋巴结复发。395 例患者选择性照射盆腔淋巴结（38.4%）。所有患者均接受前列腺窝 sRT：103 例（10.0%）接受剂量<66Gy，551 例（53.5%）接受剂量 66-70Gy，375 例（36.5%）接受剂量>70Gy。325 例（31.6%）患者接受 ADT。多变量 Cox 比例风险回归分析显示，治疗前 PSA 水平（危险比[HR]，1.80[95%CI，1.41-2.31]）、手术标本国际泌尿病理学会分级（5 级比 1+2：HR，2.39[95%CI，1.63-3.50]）、pT 分期（pT3b+pT4 比 pT2：HR，1.91[95%CI，1.39-2.67]）、手术切缘（R0 比 R1+R2+Rx：HR，0.60[95%CI，0.48-0.78]）、ADT 使用（HR，0.49[95%CI，0.37-0.65]）、sRT 剂量（>70 比≤66Gy：HR，0.44[95%CI，0.29-0.67]）和 PSMA-PET 扫描上检测到的淋巴结复发（HR，1.42[95%CI，1.09-1.85]）与 FFBF 相关。FFBF 的内部验证队列和外部异常值验证队列的平均（SD）列线图一致性指数分别为 0.72（0.06）和 0.67（0.11）。
这项前列腺癌患者队列研究提出了一个内部和外部验证的列线图，可以估计 PSMA-PET 指导下 sRT 后患者的个体预后。
