The aim of the study was to confirm the diagnostic accuracy of a second FDG-PET/CT following neoadjuvant or induction chemotherapy (NAIC) prior to radical cystectomy for patients with localized muscle-invasive bladder cancer (MIBC).
Retrospective review of 62 consecutive patients with MIBC, that had a first FDG-PET/CT between April 2016 and September 2021. Patients then underwent NAIC, followed by a second FDG-PET/CT and radical cystectomy. Patients with no hypermetabolism in the bladder and lymph nodes on the second FDG-PET/CT were considered metabolic complete responders, while patients with no evidence of residual disease on histopathology were considered pathologic complete responders. The accuracy of the second FDG-PET/CT to distinguish complete responders from patients with residual disease was calculated, with histopathology as gold standard.
Of 62 patients, 1 was lost to follow-up, 5 died before radical cystectomy, 5 had delay >2 months between the second FDG-PET/CT and radical cystectomy, and 6 did not undergo radical cystectomy and instead underwent alternative treatment. The study cohort comprised 45 patients, 39 males and 6 females, with an age of 66 ± 6 years. In comparison to histopathology, FDG-PET/CT provided (i) sensitivity of 95% and specificity of 42%, for the overall disease; (ii) sensitivity of 100% and specificity of 36%, for the primary tumor only; and (iii) sensitivity of 97% and specificity of 30%, for the lymph nodes only.
FDG-PET/CT has over 95% sensitivity for distinguishing complete responders from patients with residual disease. Thus, FDG-PET/CT can be used for early response evaluation following NAIC to identify patients that did not completely respond to chemotherapy and may require alternative treatment pathways.
Urologia internationalis. 2023 Jan 19 [Epub ahead of print]
Olivier Fitoussi, Jean Baptiste Roche, Julien Riviere, Hervé Wallerand, Jean Eude Poulain, Pierre Gordien, Sigolène Galland, Bénédicte Henriques, Camille Dupin, Muriel Vincent, Thomas Kuratle, Mo Saffarini, Sonia Ramos-Pascual
Polyclinique Bordeaux Nord Aquitaine, Bordeaux, France., Clinique St Augustin, Bordeaux, France., Clinique Bel Air, Bordeaux, France., Laboratoire de Cytologie et d'anatomie pathologique CAP, Le Bouscat, France., ReSurg SA, Nyon, Switzerland.