我们的目标是评估177Lu-PSMA放射性配体疗法（PSMA-RLT）治疗转移性去势抵抗性前列腺癌（mCRPC）患者的治疗结束时的前列腺特异性膜抗原（PSMA）PET/CT（PSMA-PET）的预后价值。方法：这是一项单中心的回顾性研究。满足最后一次PSMA-RLT周期后6个月内进行PSMA-RLT并可获得基线PSMA-PET（bPET）和治疗结束时的PSMA-PET（ePET）的mCRPC患者符合入组条件。收集了治疗结束时的总生存期（OS）和PSA进展状态（根据前列腺癌临床试验工作组3标准）。进行PSMA-PET肿瘤分割以获得全身PSMA肿瘤体积（PSMA-VOL）并定义进展性（≥20%增加）与非进展性疾病。对bPET和ePET的成对解释以观察是否出现新病变。还应用了PSMA-PET/CT响应评价标准（RECIP）1.0来定义进展性和非进展性疾病。通过Kaplan-Meier分析评估PSMA-VOL变化、新病变、RECIP 1.0和治疗结束时的PSA进展状态与OS之间的关联。结果：共纳入20例mCRPC患者。治疗周期的中位数为3.5个（四分位数范围[IQR]，2-4）。bPET到第1个PSMA-RLT周期之间的中位数时间为1.0个月（IQR，0.7-1.8个月）。最后一次PSMA-RLT和ePET之间的中位数时间为1.9个月（IQR，1.2-3.5个月）。20名患者中有12名（60%）在最后一次随访时已经死亡。存活患者从ePET开始的中位随访时间为31.2个月（IQR，6.8-40.7个月）。从ePET开始的中位OS为11.4个月（IQR，6.8-30.7个月）。在ePET上出现新病变的患者的OS比未出现新病变的患者更短（中位OS，10.7个月[95% CI，9.2-12.2个月] vs.未达到；P = 0.002）。PSMA-VOL进展的患者的OS比非进展性PSMA-VOL患者更短（中位OS，10.7个月[95% CI:9.7-11.7个月] vs.未达到；P = 0.007）。RECIP进展的患者的OS比非进展性RECIP患者更短（中位OS，10.7个月[95% CI，9.7-11.7个月] vs.未达到；P = 0.007）。治疗结束时的PSA进展与更短的OS相关（中位数，10.9个月[95% CI，9.4-12.4个月] vs.未达到；P = 0.028）。结论：在这项针对20例接受PSMA-RLT治疗的mCRPC患者的回顾性研究中，根据ePET中新病变的出现、PSMA-VOL的变化和RECIP 1.0的情况进行进展预后评估。需要在更大规模的前瞻性多中心临床试验中验证。© 2023年核医学与分子成像学会。

Our objective was to evaluate the prognostic value of end-of-treatment prostate-specific membrane antigen (PSMA) PET/CT (PSMA-PET) in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with 177Lu-PSMA radioligand therapy (PSMA-RLT). Methods: This was a single-center retrospective study. mCRPC patients who underwent PSMA-RLT with available baseline PSMA-PET (bPET) and end-of-treatment PSMA-PET (ePET) within 6 mo of the last PSMA-RLT cycle were eligible. Overall survival (OS) and prostate-specific antigen (PSA) progression status at the time of ePET (by Prostate Cancer Clinical Trials Working Group 3 criteria) were collected. PSMA-PET tumor segmentation was performed to obtain whole-body PSMA tumor volume (PSMA-VOL) and define progressive (≥20% increase) versus nonprogressive disease. Pairs of bPET and ePET were interpreted for appearance of new lesions. Response Evaluation Criteria in PSMA-PET/CT (RECIP) 1.0 were also applied to define progressive versus nonprogressive disease. The associations between changes in PSMA-VOL, new lesions, RECIP 1.0, and PSA progression status at the time of ePET with OS were evaluated by Kaplan-Meier analysis. Results: Twenty mCRPC patients were included. The median number of treatment cycles was 3.5 (interquartile range [IQR], 2-4). The median time between bPET and cycle 1 of PSMA-RLT was 1.0 mo (IQR, 0.7-1.8 mo). The median time between the last cycle of PSMA-RLT and ePET was 1.9 mo (IQR, 1.2-3.5 mo). Twelve of 20 patients (60%) had died at the last follow-up. The median follow-up time from ePET for survivors was 31.2 mo (IQR, 6.8-40.7 mo). The median OS from ePET was 11.4 mo (IQR, 6.8-30.7 mo). Patients with new lesions on ePET had shorter OS than those without new lesions (median OS, 10.7 mo [95% CI, 9.2-12.2] vs. not reached; P = 0.002). Patients with progressive PSMA-VOL had shorter OS than those with nonprogressive PSMA-VOL (median OS, 10.7 mo [95% CI: 9.7-11.7 mo] vs. not reached; P = 0.007). Patients with progressive RECIP had shorter OS than those with nonprogressive RECIP (median OS, 10.7 mo [95% CI, 9.7-11.7 mo] vs. not reached; P = 0.007). PSA progression at the time of ePET was associated with shorter OS (median, 10.9 mo [95% CI, 9.4-12.4 mo] vs. not reached; P = 0.028). Conclusion: In this retrospective study of 20 mCRPC patients treated with PSMA-RLT, progression on ePET by the appearance of new lesions, changes in PSMA-VOL, and RECIP 1.0 was prognostic for OS. Validation in larger, prospective multicentric clinical trials is warranted.© 2023 by the Society of Nuclear Medicine and Molecular Imaging.