Patients with HPV-positive head and neck tumors, primarily OPC, who are indicated for conservative radiation therapy or concurrent chemoradiation therapy will be enrolled in the study. At defined time points (before the start of treatment and during treatment), oral swabs, oral cavity washings, and peripheral blood samples will be collected, from which plasma will be isolated for analysis of viral ctDNA. We estimate approximately 20 patients with OPC indicated for radiotherapy alone or concurrent chemoradiotherapy who are p16-positive. Negative controls will be patients with OPC indicated for radiotherapy alone or concurrent chemoradiotherapy who are p16-negative (approximately 10-15).
