18F-FDG-PET/CT in staging, restaging, and treatment response assessment of male breast cancer

Abstract Purpose Male breast cancer (BC) is a rare disease, with patterns different from those found in women. Most tumors are detected at more advanced stages than in women. The aim of this study was to analyze the performance of [18F]fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG-PET/CT) in staging, restaging, and therapy response assessment. Methods We performed a systematic analysis in the database of Saint-Louis Hospital to identify male patients with BC referred for PET/CT. 18 F-FDG-PET/CT findings considered suspicious for malignancy were compared to biopsy results, further work-up and/or patient follow-up of at least 6 months. Performances of 18 F-FDG-PET/CT were compared to that of conventional imaging (CI) using the McNemar test. The impact of PET/CT on management was evaluated. Results During 6 consecutive years, among 12,692 18 F-FDG-PET/CT oncology studies, 30 were performed in 15 men with BC: 7 examinations for initial staging, 11 for restaging, and 12 for response assessment. Tumors profile was ER+ and one had HER2 overexpression. PET/CT sensitivity, specificity, positive predictive value, negative predictive value and accuracy to detect distant metastases were 100%, 67%, 86%, 100% and 89%, respectively. PET/CT was more informative than CI in 40% of studies ( p  = 0.03; 95% confidence interval: 3.26 – 40%). Findings from 18 F-FDG-PET/CT led to modification in the planned treatment in 13/30 cases (43%). Conclusion Although all the tumors were ER+, primary lesions and metastases were diagnosed with high sensitivity. 18 F-FDG-PET/CT seems to be a powerful imaging method to perform staging, restaging and treatment response assessment in male patients with BC.