Defining the Risk of Involvement for Each Neck Nodal Level in Patients With Early T-Stage Node-Positive Oropharyngeal Carcinoma

Levels IB and V are at very low (<5%) risk of involvement, even with ipsilateral to pathologically proven neck disease; this can guide radiation planning. Levels II and III should be included in high-risk volumes regardless of imaging results, and Level IV should be included within the lowest risk volume.