简介：前列腺特异性膜抗原正电子发射断层扫描 (PSMA-PET) 通常用于前列腺癌患者的分期，但疗效评估的数据很少，并且主要来自接受 PSMA 治疗的转移性去势抵抗性前列腺癌 (mCRPC) 患者放射配体治疗。尽管如此，在疾病早期阶段仍会采用后续 PSMA-PET，以防临床怀疑疾病持续、复发或进展，以决定是否需要局部或全身治疗。因此，PSMA-PET 衍生的肿瘤体积在早期疾病阶段（即激素敏感型前列腺癌 (HSPC) 和非 [177Lu]Lu-PSMA-617 (LuPSMA) 治疗去势抵抗性前列腺癌 (CRPC)）的预后价值在本手稿中进行了评估。方法：共有 73 名患者（6 名初次分期、42 名 HSPC、25 名 CRPC）接受了两次（即基线和随访，中位间隔：379 天）全身 [68Ga]Ga-PSMA-11 PET/CT 2014 年 11 月至 2018 年 12 月期间进行的扫描。分析仅限于非 LuPSMA 治疗患者。回顾性分析 PSMA-PET，并对原发肿瘤、淋巴结、内脏和骨转移进行分割。测量体重调整后的器官特异性体积和总肿瘤体积（PSMAvol：所有病变的 PET 体积之和）以进行基线和随访。 PSMAvol 反应计算为全身肿瘤体积的绝对差。确定高转移负荷（> 5 个转移）、RECIP 1.0 和 PSMA-PET 进展标准 (PPP)。生存数据来自癌症登记处。结果：初次 PET 检查时每位患者的平均肿瘤病灶数为 10.3 个（SD 28.4）。基线时，PSMAvol 与 OS 密切相关（HR 3.92，p <0.001；n = 73）。同样，PSMAvol 的反应与 OS 显着相关（HR 10.48，p < 0.005；n = 73）。 PPP 也取得了显着效果（HR 2.19，p <0.05，n = 73）。患有激素敏感性疾病且随访中 PSMAvol 反应较差（PSMAvol 变化的上四分位数）的患者预后较短（p < 0.05；n = 42）。骨骼中的 PSMAvol 是基线 OS 预测和反应评估最相关的参数（HR 31.11 p < 0.001；HR 32.27，p < 0.001；n = 73）。结论：在目前的异质队列中，PPP 和 PSMAvol 反应与 OS 显着相关。骨肿瘤体积是 OS 预测的相关 miTNM 区域。未来对器官特异性 PSMAvol 在更同质群体中的表现进行前瞻性评估似乎是有必要的。© 作者。

Introduction: Prostate Specific Membrane Antigen Positron Emission Tomography (PSMA-PET) is routinely used for the staging of patients with prostate cancer, but data on response assessment are sparse and primarily stem from metastatic castration-resistant prostate cancer (mCRPC) patients treated with PSMA radioligand therapy. Still, follow-up PSMA-PET is employed in earlier disease stages in case of clinical suspicion of disease persistence, recurrence or progression to decide if localized or systemic treatment is indicated. Therefore, the prognostic value of PSMA-PET derived tumor volumes in earlier disease stages (i.e., hormone-sensitive prostate cancer (HSPC) and non-[177Lu]Lu-PSMA-617 (LuPSMA) therapy castration resistant prostate cancer (CRPC)) are evaluated in this manuscript. Methods: A total number of 73 patients (6 primary staging, 42 HSPC, 25 CRPC) underwent two (i.e., baseline and follow-up, median interval: 379 days) whole-body [68Ga]Ga-PSMA-11 PET/CT scans between Nov 2014 and Dec 2018. Analysis was restricted to non-LuPSMA therapy patients. PSMA-PETs were retrospectively analyzed and primary tumor, lymph node-, visceral-, and bone metastases were segmented. Body weight-adjusted organ-specific and total tumor volumes (PSMAvol: sum of PET volumes of all lesions) were measured for baseline and follow-up. PSMAvol response was calculated as the absolute difference of whole-body tumor volumes. High metastatic burden (>5 metastases), RECIP 1.0 and PSMA-PET Progression Criteria (PPP) were determined. Survival data were sourced from the cancer registry. Results: The average number of tumor lesions per patient on the initial PET examination was 10.3 (SD 28.4). At baseline, PSMAvol was strongly associated with OS (HR 3.92, p <0.001; n = 73). Likewise, response in PSMAvol was significantly associated with OS (HR 10.48, p < 0.005; n = 73). PPP achieved significance as well (HR 2.19, p <0.05, n = 73). Patients with hormone sensitive disease and poor PSMAvol response (upper quartile of PSMAvol change) in follow-up had shorter outcome (p < 0.05; n = 42). PSMAvol in bones was the most relevant parameter for OS prognostication at baseline and for response assessment (HR 31.11 p < 0.001; HR 32.27, p < 0.001; n = 73). Conclusion: PPP and response in PSMAvol were significantly associated with OS in the present heterogeneous cohort. Bone tumor volume was the relevant miTNM region for OS prognostication. Future prospective evaluation of the performance of organ specific PSMAvol in more homogeneous cohorts seems warranted.© The author(s).