Objectives. The aim of the present study was to assess the performance of radiolabeled-PSMA PET/CT in a cohort of intermediate-risk prostate cancer (PCa) patients for initial staging. Methods. This is a retrospective, multicenter analysis of patients diagnosed with intermediate-risk PCa who were staged using radiolabeled PSMA PET/CT to evaluate the extent of the disease before initiating appropriate treatment. The study included patients from the Nuclear Medicine Units of the Humanitas group between 2021 and 2024. The change in management due to the PSMA PET/CT examination was assessed. Results. A total of 181 patients were enrolled across all three centers. Histopathological assessment from biopsy revealed that 51.4% of patients had favorable PCa, while 48.6% had unfavorable disease. PET/CT was positive for the primary lesions in all patients, but it revealed a positivity rate in 23 (12.7%) patients for nodes and distant organs, with a positivity rate of 0.21 in the unfavorable group and 0.05 in the favorable group (p < 0.005). Based on follow-up data, diagnostic accuracy was higher than 90% in both the favorable and unfavorable groups for lymph node and distant metastases. The inclusion of PSMA PET/CT in the diagnostic algorithm for patients with intermediate-risk PCa impacted patient management in 24 (13.3%) cases, based on the multidisciplinary team decision. Conclusions. PSMA PET/CT can affect the management of patients with intermediate-risk PCa in up to 13% of cases, mainly for unfavorable diseases. New imaging techniques as a first-line imaging procedure can help to plan the correct therapeutic approach in the intermediate-risk PCa group.
Background/Objectives: Assessing treatment response in neuroendocrine tumors (NETs) remains challenging. The multifactorial mechanism of action of peptide receptor radionuclide therapy (PRRT) further complicates response evaluation, particularly in the absence of standardized criteria. This study aimed to compare different imaging-based response assessment methods after PRRT and to explore their relationship with clinical outcomes, particularly progression-free survival (PFS). Methods: In this single-center retrospective study, we analyzed NET patients treated with PRRT between 2020 and 2024 who underwent [68Ga]Ga-DOTATOC PET/CT before and after therapy, with a minimum follow-up of 12 months. Five response criteria were evaluated: (a) Krenning Score changes; (b) adapted PERCIST criteria (MORE); (c) ZP-normalized parameter; (d) qualitative visual PET assessment; and (e) RECIST-based morphological response on contrast-enhanced CT. Imaging findings were correlated with clinical outcomes. Nonparametric analyses were performed using the MedCalc® software. Results: Thirty-one patients (median age 63 years; 17 males) with NET were evaluated after PRRT. Post-PRRT PET/CT was performed at a median of 3 months. Response rates varied across methods, with higher rates noted using functional imaging (MORE 66%, Visual PET 68%, ZP 70%) compared to RECIST (40%) and Krenning score (21%). After a median follow-up of 37 months, 58% of patients experienced disease progression. Although no significant association was found between the response criteria and progression (p > 0.05), functional imaging showed a trend toward better correlation with longer progression-free survival. Conclusions: Functional PET-based responsecriteria suggest association with progression-free survival compared to RECIST criteria and Krenning score changes. However, given the exploratory nature of the study and its methodological limitations, these observations should be considered hypothesis-generating only. They do not provide definitive evidence of superiority over established assessment methods and therefore should not be interpreted as practice-changing.