Shaping the role of FDG PET in bladder cancer: current evidence and ongoing clinical trial.

BACKGROUND

This review aims to summarize and critically evaluate published clinical trials investigating the role of [18F]FDG PET in bladder cancer (BC) management, and to provide an overview of ongoing trials in this field.

METHODS

A literature search was conducted in PubMed up to 31 August 2025 and on ClinicalTrials.gov to identify clinical trials assessing the role of [18F]FDG PET/CT in patients with BC. The search strategy used the terms "FDG PET," "bladder cancer," "PET/CT," "clinical trials," and "PET/MRI." Review articles, editorials, letters, comments, and case reports were excluded. Two investigators independently screened the literature, and additional trial information was retrieved from ClinicalTrials.gov.

RESULTS

Five eligible full-text publications and eight registered clinical trials were identified. Among the publications, two reported study protocols, two were pilot studies, and one was an ancillary analysis from a larger trial. In addition, eight ongoing clinical trials were retrieved from ClinicalTrials.gov. Available data suggest that [18F]FDG PET/MRI may be more suitable than PET/CT for evaluating primary bladder lesions, while PET/CT is particularly effective in detecting distant metastases. Several ongoing studies are also investigating delayed acquisition protocols to improve detection of nodal metastases.

CONCLUSIONS

[18F]FDG PET/CT and PET/MRI show promise for enhancing local and distant staging in muscle-invasive bladder cancer, although their role in nodal evaluation remains uncertain. Current evidence is limited by heterogeneous study designs, small patient cohorts, and the lack of standardized imaging protocols.