Background:PSMA PET/CT imaging has become a cornerstone in the management of prostate cancer, particularly in the setting of biochemical recurrence (BCR). While semi-quantitative parameters such as SUVmean have been evaluated as prognostic biomarkers in metastatic castration-resistant prostate cancer (mCRPC), particularly after the VISION trial, the prognostic role of volumetric measures such as Total Molecular Volume (TMV) remain largely unexplored, especially in earlier stages of the disease such as in biochemical recurrence following primary treatment.Methods:This retrospective monocentric study included 84 patients with BCR who underwent PSMA PET/CT imaging between 2020 and 2021 using either [68Ga]Ga-PSMA-11(Ga-PSMA) or [18F]-PSMA-1007 (F-PSMA) as tracers. Total tumor burden was assessed through manual 3D segmentation to derive whole-body Total Molecular Volume (wb TMV) and Total Lesion PSMA (wb TL-PSMA). Clinical and imaging variables were correlated with overall survival (OS) and progression-free survival (PFS) using Cox regression models. Kaplan–Meier analyses were performed based on wb TMV and thresholds determined by the Youden index.Results:A PSMA PET/CT correlation for BCR was identified in 69% of patients, with comparable detection rates between tracers (Ga-PSMA 67% vs. F-PSMA 63%,p= 0.7). A higher wb TMV was significantly associated with worse OS (HR 2.20,p< 0.001) and PFS (HR 2.01,p< 0.001) in univariable analyses. In multivariable models, log2(wb TMV) remained an independent prognostic factor for PFS (HR 1.78,p= 0.005). Patients with log2(wb TMV) > 2.87 exhibited significantly poorer survival outcomes. A PSA at diagnosis > 17 ng/mL also predicted shorter PFS.Conclusions:Tumor segmentation from PSMA PET/CT imaging provides powerful prognostic information in patients with biochemical recurrence of prostate cancer, independently of the tracer used. The wb TMV represents a promising volumetric biomarker for future risk stratification and therapeutic decision-making, particularly in earlier stages of prostate cancer progression, where predictive imaging biomarkers remain largely undefined.
背景：PSMA PET/CT成像已成为前列腺癌管理，尤其是在生化复发（BCR）情况下的关键手段。尽管半定量参数如SUVmean已被评估为转移性去势抵抗性前列腺癌（mCRPC）的预后生物标志物，特别是在VISION试验之后，但体积测量指标如总分子体积（TMV）的预后作用在很大程度上仍未得到探索，尤其是在疾病的早期阶段，如初次治疗后的生化复发。 方法：这项回顾性单中心研究纳入了84名BCR患者，他们在2020年至2021年间接受了PSMA PET/CT成像，使用的示踪剂为[68Ga]Ga-PSMA-11（Ga-PSMA）或[18F]-PSMA-1007（F-PSMA）。通过手动三维分割评估总肿瘤负荷，得出全身总分子体积（wb TMV）和全身总病灶PSMA（wb TL-PSMA）。使用Cox回归模型将临床和影像学变量与总生存期（OS）和无进展生存期（PFS）相关联。基于wb TMV和Youden指数确定的阈值进行了Kaplan-Meier分析。 结果：在69%的患者中发现了PSMA PET/CT与BCR的相关性，两种示踪剂的检出率相当（Ga-PSMA 67% vs. F-PSMA 63%，p=0.7）。在单变量分析中，较高的wb TMV与较差的OS（HR 2.20，p<0.001）和PFS（HR 2.01，p<0.001）显著相关。在多变量模型中，log2(wb TMV)仍然是PFS的独立预后因素（HR 1.78，p=0.005）。log2(wb TMV) > 2.87的患者生存结局显著较差。诊断时PSA > 17 ng/mL也预示着较短的PFS。 结论：PSMA PET/CT成像的肿瘤分割为前列腺癌生化复发患者提供了强有力的预后信息，且与所使用的示踪剂无关。wb TMV代表了一种有前景的体积生物标志物，可用于未来的风险分层和治疗决策，特别是在前列腺癌进展的早期阶段，该阶段的预测性影像学生物标志物在很大程度上仍未明确。
肿瘤(癌症)患者之家