Accuracy of radiographic nodal counts in HPV-positive oropharyngeal cancer and impact on treatment.

In HPV-associated (HPV + ) oropharyngeal squamous cell carcinoma (OPSCC), pathological nodal count informs adjuvant therapy recommendations. The accuracy of preoperative radiographic nodal assessment at clinically important thresholds remains unknown. The goal of this research was to determine the diagnostic accuracy of preoperative radiographic nodal counts compared with pathological findings in HPV + OPSCC. In this retrospective cohort study (2016-2024) of 292 patients with HPV + OPSCCa treated with transoral robotic surgery (TORS) at our institution, specialized head and neck radiologists were blinded to pathological results and reviewed pre-operative imaging for the presence of cervical lymph nodes. Lymph nodes were classified as positive, suspicious, or negative based on established criteria, and were compared to the final pathological results. The overall correlation of cN versus pN was 0.70. Radiography showed a high sensitivity (0.94) and PPV (0.98) for positive nodes. Adding suspicious nodes increased sensitivity (0.96) but reduced specificity (0.57). Among patients with 3 radiographic nodes, the proportion with 5 or more pathological nodes was low (5 %; OR, 1.24; P = 0.58). The highest accuracy between radiographically and pathologically positive nodes was in level II (0.91), and level III had the lowest accuracy (0.74). These findings demonstrate that imaging was able to reliably identify pathological nodal metastases when using a strict definition of positive nodes, but inclusion of suspicious nodes overestimated pathological nodal burden. There was no significant association between 3 radiographic positive nodes and 5 or more pathological nodes, underscoring that this patient population may still appropriate for upfront surgical management.