68Gallium-labeled prostate-specific membrane antigen-11 (PSMA) PET/CT is the new reference to identify relapse during biochemical recurrence of prostate cancer (PCa). However, this method lacks specificity for bone foci. This study aimed to report the prevalence of PCa bone metastases and to assess the diagnostic performances of PSMA reporting and data systems (RADS), clinical, biological, and imaging features for identification.
A multicentric retrospective cohort of consecutive patients with biochemical recurrence after local treatment was analyzed. Clinical and biological features at initial staging and during recurrence were retrieved from medical reports. The metastatic status of each bone uptake on PSMA PET/CT was determined according to histopathology, comparisons with concomitant and previous conventional imaging, prostate-specific antigen kinetic, and follow-up. Two nuclear medicine physicians assessed PSMA-RADS, anatomic location, radiological patterns, SUVmax, and the presence of other molecular lesions. Univariate and multivariate analyses were conducted to identify independent predictors of PCa metastases.
In the eligible population, 98/298 patients (32.9%) showed bone uptake on PSMA PET/CT. In patients with a final diagnosis, 28/81 lesions (34.6%) were metastases. PSMA-RADS-4 or 5 showed sensitivity of 79%, specificity of 94%, and accuracy of 89%. PSMA-RADS had a significantly higher area under the receiver operating characteristic curve than the initial reading in clinical practice (0.91 vs 0.83, P = 0.0074). Initial Gleason score ≥8, age ≤71 years at recurrence, and SUVmax >6.21 were independent predictors of PCa metastases in multivariate logistic regression (P = 0.0314, 0.0179, and 0.0003, respectively).
Most bone uptakes at PSMA PET/CT were benign lesions. PSMA-RADS, patients and tumor characteristics, and SUVmax could help identify PCa bone metastases.
Clinical nuclear medicine. 2022 May 11 [Epub ahead of print]
Anouk Letang, Amandine Crombé, Caroline Rousseau, Paul Sargos, Charles Merlin, Coralie Cantarel, Anne-Laure Cazeau
From the Departments of Nuclear Medicine., ICO René Gauducheau, F-44800 Saint-Herblain, Nantes Université, Univ Angers, INSERM, CNRS, CRCI2NA, F-44000 Nantes., Department of Radiotherapy, Institut Bergonié, Bordeaux., Department of Nuclear Medicine, Centre Jean Perrin Cancer Center, Clermont-Ferrand., Clinical and Epidemiological Research Unit, INSERM CIC1401, Institut Bergonié, Comprehensive Cancer Center, Bordeaux, France.