Radiologic Extranodal Extension Portends Worse Outcome in cN+ TNM-8 Stage I Human Papillomavirus–Mediated Oropharyngeal Cancer

To identify adverse radiologic nodal features in cN+ TNM-8 stage I human papillomavirus-related (HPV+) oropharyngeal cancer (OPC).All patients with HPV+ cT1-T2cN1 OPC treated with definitive intensity modulated radiation therapy from 2008 to 2015 were included. Radiologically involved lymph node number (LN), radiologic extranodal extension (rENE), retropharyngeal LN (RPLN), and lower neck (level 4 or 5b) LN involvement were assessed on...