Prognostic value of post-treatment¹⁸F-FDG PET/CT for advanced head and neck cancer after combined intra-arterial chemotherapy and radiotherapy

Objective: To clarify the prognostic value of post-treatment ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in patients with advanced head and neck squamous cell carcinoma (HNSCC) after combined intra-arterial chemotherapy and radiotherapy (IACR). Methods: Thirty-six patients with HNSCC who underwent IACR were recruited. The period from the end of IACR to the last post-treatment ¹⁸F-FDG PET/CT examination was 8-12 weeks. Both patient-based and lesion-based analyses were used to evaluate the PET/CT images. For lesion-based analysis, 36 regions (12 lesions of recurrences and 24 scars at primary sites) were selected. The Kaplan-Meier method was used to assess the overall survival (OS) stratified by ¹⁸F-FDG uptake or visual interpretation results. Results: Twelve patients with recurrence were identified by six months after IACR. The sensitivity and specificity in the patient-based analysis were 67% (8/12) and 88% (21/24), respectively. The mean OS was estimated to be 12.1 months (95% CI, 6.3-18.0 months) for the higher maximum standardized uptake value (SUV_max) group (n=7) and 44.6 months (95% CI, 39.9-49.3 months) for the lower SUV_max group (n=29). OS in the higher SUV _max group (cut-off point, 6.1) or positive visual interpretation group was significantly shorter than that in the lower SUV_max or negative visual interpretation group (P<0.001 and P<0.05, respectively). Conclusions: The SUV_max and visual interpretation of HNSCC on post-IACR ¹⁸F-FDG PET/CT can provide prognostic survival estimates.