Early evaluation of neoadjuvant chemotherapy response using FDG-PET/CT predicts survival prognosis in patients with head and neck squamous cell carcinoma

Abstract

The purpose of this study was to investigate the possibility of early survival prediction after completion of one cycle of neoadjuvant chemotherapy (NAC) by positron emission tomography (PET)/computed tomography (CT) with (18)F-fluorodeoxyglucose (FDG). Fifty-seven patients with advanced head and neck squamous cell carcinoma (HNSCC) underwent FDG-PET/CT scans twice, before and after one cycle of NAC. We calculated the maximal standardized uptake value (SUV(max)) for a primary tumor and/or metastatic lymph nodes and defined %decrease as the %difference in SUV(max) between the two scans divided by that of the initial scan. Patients were classified as responders by PET (%decrease ≥55.5% or post-NAC SUV(max) ≤3.5) and by RECIST (≥30% decrease in size). The local control (LC) rate and the disease-specific survival (DSS) rate were assessed between the responders and non-responders. Multivariate analysis was also performed using the Cox proportional hazards model. In univariate analysis, the PET finding of a primary site was a significant risk factor for LC and DSS rates at 2 years after completion of NAC (P = 0.03 and 0.02, respectively), but there was no difference between responders and non-responders by the RECIST criteria. In a multivariate regression analysis, the PET finding in the primary site and the definitive therapy choice were independent prognostic factors in LC, while the PET finding in the primary site was the only independent prognostic factor in DSS. Our preliminary data indicate that the PET finding in the primary lesion after one cycle of NAC was an independent prognostic factor in LC and DSS in patients with HNSCC.