The trial will assess the effects of aggressive hypofractionated radiation therapy in patients with oral cavity, oropharynx, hypopharynx, or larynx cancer after surgical resection with pathology showing intermediate risk factors requiring post-operative radiation therapy without concurrent chemotherapy. During Phase 1, the maximum tolerated dose/fractionation and tolerability will be determined. During Phase 2, patients will be randomized between conventionally fractionated radiation therapy (6 weeks) vs. hypofractionated radiation therapy (3-4 weeks depending on Phase 1 results) to establish non-inferiority of hypofractionated radiation therapy.

