Abstract Background Radioligand therapy targeting prostate-specific membrane antigen is an established treatment for patients with metastatic castration-resistant prostate cancer. Accurate quantification of tumor burden on PSMA PET/CT is essential for prognostic stratification and therapeutic planning. PSMA-derived tumor volume has emerged as a strong imaging biomarker for overall survival in this population. However, variability in segmentation approaches may affect volumetric measurements and limit clinical comparability. This study compares two segmentation methods—semi-automated threshold-based segmentation using Syngo.via and fully automated, artificial intelligence-driven analysis with aPROMISE—to evaluate their prognostic value for baseline tumor burden in patients undergoing radioligand therapy. Results Baseline PSMA PET/CT scans from 111 patients with metastatic castration-resistant prostate cancer were retrospectively analyzed. Tumor volumes differed significantly between the two segmentation methods, with mean volumes of 190.11 mL using Syngo.via and 1123.63 mL using aPROMISE (pConclusions Despite notable differences in absolute tumor volume estimates, both Syngo.via and aPROMISE provided comparable prognostic value for overall survival in patients with metastatic castration-resistant prostate cancer undergoing PSMA radioligand therapy. These findings support the integration of tumor volume as a prognostic imaging biomarker in clinical practice. Importantly, consistent use of a single segmentation platform is recommended for reliable longitudinal assessment and clinical decision-making.
Raad et al. (Thu,) studied this question.