Surveillance Imaging Following Head and Neck Cancer Treatment and Microvascular Reconstruction.

OBJECTIVES/HYPOTHESIS: To assess the accuracy and utility of positron emission tomography/computed tomography (PET/CT) compared with magnetic resonance imaging (MRI) for detecting head and neck cancer (HNC) recurrence after microvascular reconstructive surgery. STUDY DESIGN: Retrospective cohort study. METHODS: Analysis of HNC patients who underwent microvascular reconstruction at a single, tertiary academic center following ablative surgery from 1998 to 2015. Forty-six patients aged 61.4 ± 15.8 years with both PET/CT and MRI examinations were identified. Two radiologists were blinded and interpreted each imaging study. Recurrence certainty scores were determined via continuous (0-100) and Likert ("Likely" to "Unlikely") scales, with larger values indicating a higher likelihood of recurrence. Pathologic confirmation of recurrence was confirmed in 23 patients (50%). RESULTS: Among those with primary site recurrences, mean recurrence certainty was significantly higher with PET/CT versus MRI on the continuous scale (63.9 vs. 44.4, P = .006). A receiver operating characteristic analysis for predicting primary site recurrence demonstrated a significantly larger area under the curve of 0.79 for PET/CT compared to 0.64 for MRI (P = .044). Categorization of "Likely" primary site recurrence on PET/CT, versus MRI, had higher sensitivity (0.63 vs. 0.40), but lower specificity (0.90 vs. 1.0). MRI demonstrated higher sensitivity (1.0 vs. 0.78) at detecting regional site recurrences. CONCLUSION: PET/CT demonstrates greater sensitivity than MRI as a surveillance tool for primary site recurrence following microvascular reconstruction where clinical evaluation is hindered by anatomical distortion. Therefore, PET/CT should be pursued as first-line imaging, with MRI utilized for confirmation of positive imaging findings at the primary site. LEVEL OF EVIDENCE: 2 Laryngoscope, 131:2713-2718, 2021.