PSMA PET/CT SUVmax as a prognostic biomarker in patients with metachronous metastatic hormone-sensitive prostate cancer (mHSPC)

Metastatic hormone-sensitive prostate cancer (mHSPC) is treatment-resistant and generally considered incurable. The development of prostate-specific membrane antigen positron emission-computed tomography (PSMA PET/CT) has generated immense expectations due to its diagnostic accuracy in prostate cancer (PCa). PSMA expression of the primary tumor, quantified by SUVmax, is a predictor of oncological outcomes. The role of PSMA-PET/CT SUVmax in metachronous mHSPC treated with ADT plus second-generation antiandrogens (ARSI) is unknown. The main aim of this study was to evaluate Ga-PSMA-11expression (SUVmax) as a potential prognostic biomarker in patients with metachronous mHSPC treated with ADT and first or second-generation antiandrogens. A second aim was to determine the association between PSMA SUVmax and PSA response to hormone therapy. Patients diagnosed with metachronous mHSPC between July 2017 and February 2023 who developed biochemical recurrence following radical surgery (with or without salvage radiotherapy and/or ADT) or external radiation therapy (with or without ADT) were included. All patients underwent Ga-PSMA-11 PET/CT imaging and the SUVmax value was determined for all measurable locations. The SUVmax value was used for the semiquantitative analysis. The Wilcoxon method was used to compare responders (PSA reduction ≥ 50%) to non-responders (PSA reduction