PET-CT vs CT Alone: Impact on Routine Nodal Staging in Muscle-Invasive Bladder Cancer

PET-CT may improve lymph-node staging and help guide treatment decisions for patients with muscle-invasive bladder cancer (MIBC), according to a retrospective study presented at the European Society for Medical Oncology (ESMO) Congress 2025.

Investigators noted that despite neoadjuvant chemotherapy followed by radical cystectomy, “about half” of patients with MIBC relapse within 5 years, and CT remains the routine imaging modality for staging. The team evaluated whether adding PET-CT could refine staging and influence therapy selection.

The analysis included 256 patients with MIBC who had no metastases identified on CT. Of these, 41 underwent PET-CT and 215 received CT alone. Researchers compared staging results and downstream treatment choices between imaging strategies.

Staging changes were common. In more than 40% of cases, staging differed when PET-CT was used versus CT alone. PET-CT also identified a higher proportion of lymph node involvement than CT alone (node-positive: 48.8% vs 23.2%; N2: 18.6% vs 11.6%; N3: 27.9% vs 11.6%), though this difference was reported as not statistically significant.

Treatment decisions diverged significantly. Nearly one-quarter of patients staged with PET-CT received palliative systemic therapy (24.3%) compared with 0.9% in the CT-only group. Cystectomy was performed more often after CT alone than after PET-CT (64.0% vs 51.2%).

Pathologic nodal “misses” appeared lower with PET-CT. Surgical specimens showed nodal involvement in 27.2% of patients labeled N0 by CT, compared with 13% of those labeled N0 by PET-CT.

Relapse outcomes favored PET-CT staging. Metastatic relapse occurred less often in the PET-CT group than in the CT-only group (9.5% vs 43.1%; P = 0.003). Median relapse-free survival was 30.13 months with CT alone and not reached with PET-CT (hazard ratio, 0.54; 95% CI, 0.17–1.7).

“The significantly lower relapse rate and better radiopathological concordance in PET-staged patients underscore its value in identifying candidates for curative treatment and avoiding undertreatment or overtreatment in MIBC,” the researchers wrote.