Impact of 18F-FDG PET/CT staging on management and prognostic stratification in head and neck squamous cell carcinoma: A prospective observational study

Abstract

BackgroundAccurate assessment of the extent of cancer is essential for appropriate treatment planning and outcome prediction. This study prospectively evaluated whether adding 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) to the routine initial staging practice in head and neck squamous cell carcinoma (HNSCC) improved management and prognosis. MethodsAll consecutive patients with newly diagnosed HNSCC who presented in October 2010 – December 2012 underwent conventional workups (CWU) followed by PET/CT. The clinical stage and management plans before and after PET/CT were compared. PET/CT was deemed to have no/low, moderate, and high impact on management planning depending on whether PET/CT changed the treatment modality or goal. The appropriateness of PET/CT staging and management impact was confirmed by histopathology and clinical follow-up, and its association with survival was analysed. FindingsOf the 248 patients, PET/CT changed the Tumour Node Metastasis (TNM) classification in 79 (31.9%). In the patients with discordant staging, PET/CT staging was significantly more sensitive and accurate than CWU staging (both P < 0.001). PET/CT had high or moderate impact on management in 39 (15.7%) patients. Patients with PET/CT upstaged disease had significantly worse progression-free survival (PFS) and overall survival (OS) than patients with no CWU-stage changes (3-year PFS = 56.8% versus 74.5%, P = 0.043; 3-year OS = 61.3% versus 85.3%, P = 0.006). Multivariate analyses revealed that PET/CT staging and second primary cancer were independent predictive factors for both PFS and OS (P < 0.05, each). Interpretations18F-FDG PET/CT added important staging information that improved management and prognostic stratification in HNSCC.