Inclusion Criteria:  Subjects ≥ 18 years old at the time of informed consent. Ability to provide written informed consent and HIPAA authorization. Eastern Cooperative Oncology Group (ECOG) performance status 0-2 (refer to Appendix). Primary tumor of the oropharynx (palatine tonsil, tongue base, soft palate, lateral or posterior walls of oropharynx). Histopathologically confirmed squamous cell carcinoma. HPV+ tumor, as determined by p16, in-situ hybridization, or real-time polymerase chain reaction. Resectable and accessible tumor with high probability of achieving negative margins. Smokers and non-smokers included. Tumor stage (AJCC 8th edition): T1 or T2. Nodal stage (AJCC 8th edition): N0, N1 or N2. Mobile neck nodes on physical exam if N positive. Subjects with synchronous primaries included. Subjects with unknown primaries included if primary is definitively identified and resectable with negative margins.  Exclusion Criteria:  Serious medical condition preventing general anesthesia for surgery. Inability to complete full course of radiation treatment or attend follow-up visits. History of previous head and neck radiation or previous head and neck cancer within 3 years. Distant metastatic disease present. Prior invasive malignant disease within 5 years, with the exception of non- melanoma skin cancer.  Lactating or pregnant women. Women of childbearing potential must have a negative pregnancy test within 30 days of protocol registration. Women are considered to have childbearing potential (regardless of sexual orientation, having undergone a tubal ligation, or remaining celibate by choice) unless the patients meet one of the following criteria:  Has undergone a hysterectomy or bilateral oophorectomy; or Has been naturally amenorrheic for at least 24 consecutive months.