Metabolic Imaging of Advanced Basal Cell Carcinoma Treated with Sonidegib: A Retrospective Case Series Study

background: positron emission tomography/computed tomography (PET/CT) with 18F-fluorodeoxyglucose (18F-FDG) is a firmly established tool in oncology and is gaining importance in dermato-oncology. however, its use in advanced basal cell carcinoma (BCC) is limited, with only a few case reports and a single study focused on vismodegib. this study evaluates the role of 18F-FDG PET/CT in advanced BCC treated with sonidegib. methods: we retrospectively assessed the clinical data of patients with advanced BCC who underwent 18F-FDG PET/CT between January 2022 and January 2024. Inclusion criteria included histologically confirmed BCC, FDG-avid lesions on baseline PET/CT, and a minimum follow-up of 6 months. metabolic response was assessed using the PET response criteria in solid tumors (PERCIST). results: four patients with advanced BCC treated with sonidegib were included, presenting with a total of 10 hypermetabolic lesions at baseline PET/CT. the mean interval between baseline and follow-up scans was 8.7 +/- 1.6 months. according to percist, two patients achieved a complete metabolic response (CMR), while the other two had stable metabolic disease (SMD). low baseline-standardized uptake values (i.e., SUVmax, SUVmean) and reduced total lesion glycolysis (TLG) were associated with CMR. no relapses were observed during follow-up. conclusions: this study suggests that 18F-FDG PET/CT may help identify advanced BCC patients who are likely to benefit from sonidegib treatment. further research is needed to fully explore the potential of PET/CT in this specific clinical context.