Posttreatment FDG‐PET/CT Hopkins criteria predict locoregional recurrence after definitive radiotherapy for oropharyngeal squamous cell carcinoma

Background Metabolic response assessment for oropharyngeal squamous cell carcinoma (OPSCC) aids in identifying locoregional persistence/recurrence (LRR). The Hopkins Criteria are a standardized qualitative response assessment system using posttreatment FDG‐PET/CT. Methods We conducted a retrospective cohort study of patients with node‐positive OPSCC treated with definitive (chemo)radiotherapy. We assessed Hopkins Criteria performance for LRR, then developed and validated a competing‐risks model. Results Between 2004 and 2018, 259 patients were included with median follow‐up of 43 months. The Hopkins Criteria sensitivity, specificity, negative predictive value, and accuracy were 68%, 88%, 95%, and 85%. The 36‐month cumulative incidence of LRR was greater with positive scores (45% vs. 5%, HR 12.60, p