Michalski Kerstin, Klein Claudius, Brueggemann Tonio, Meyer Philipp T, Jilg Cordula Annette, Ruf Juri
Department of Nuclear Medicine, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany, Germany.
Department of Urology, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany.
J Nucl Med. 2021 Mar 31;62(12):1741-6. doi: 10.2967/jnumed.120.260836.
Positron emission tomography/computer tomography (PET/CT) targeting the prostate specific membrane antigen (PSMA) plays a key role in staging of patients with prostate cancer (PCa). Moreover, it is not only used for the assessment of adequate PSMA expression of PCa cells before PSMA-targeting radioligand therapy (PSMA RLT) but also for re-staging during the course of therapy to evaluate response to treatment. Whereas no established criteria exist for systematic response evaluation so far, recently proposed PSMA PET Progression (PPP) criteria might fill this gap. The aim of this study was to assess the feasibility of PPP criteria in patients undergoing PSMA RLT and their prognostic implications. In this retrospective analysis, PSMA PET/CT scans of 46 patients acquired before and after completion of PSMA RLT were analyzed separately by two readers using modified PPP criteria. After interobserver agreement assessment, consensus results (progressive vs. non-progressive disease) were compared in a multivariate cox regression model (endpoint overall survival, OS). Interobserver agreement on modified PPP criteria was substantial (Cohens κ = 0.73) with a concordance in 87% of patients. Median OS of all patients after PSMA RLT ( = 46) was 9.0 [95% confidence interval (CI) 7.8 - 10.2] months. Progression according to modified PPP criteria was found in 32 patients and was a significant (p ≤0.001) prognostic marker for OS with a hazard ratio of 15.5 [95% CI 3.4 - 70.2]. Response assessment in patients undergoing PSMA RLT using modified PPP criteria are reproducible and highly prognostic for OS. Modified PPP criteria should be validated in future prospective trials.
靶向前列腺特异性膜抗原（PSMA）的正电子发射断层扫描/计算机断层扫描（PET/CT）在前列腺癌（PCa）患者的分期中起着关键作用。此外，它不仅用于在靶向PSMA的放射性配体治疗（PSMA RLT）前评估PCa细胞的PSMA表达是否充足，还用于在治疗过程中重新分期以评估治疗反应。尽管目前尚无用于系统反应评估的既定标准，但最近提出的PSMA PET进展（PPP）标准可能会填补这一空白。本研究的目的是评估PPP标准在接受PSMA RLT患者中的可行性及其预后意义。在这项回顾性分析中，两名阅片者使用改良的PPP标准分别分析了46例患者在PSMA RLT完成前后进行的PSMA PET/CT扫描。在评估观察者间一致性后，在多变量cox回归模型（终点为总生存期，OS）中比较了共识结果（疾病进展与非进展）。观察者间对改良PPP标准的一致性较高（科恩斯κ系数=0.73），87%的患者结果一致。PSMA RLT后所有患者（n=46）的中位OS为9.0[95%置信区间（CI）7.8 - 10.2]个月。根据改良PPP标准发现32例患者有疾病进展，这是OS的一个显著（p≤0.001）预后标志物，危险比为15.5[95%CI 3.4 - 70.2]。使用改良PPP标准对接受PSMA RLT患者进行反应评估具有可重复性，且对OS具有高度预后价值。改良的PPP标准应在未来的前瞻性试验中进行验证。
