This study will test whether limiting standard photon intensity modulated radiation therapy (IMRT) to exclude the oral tongue surgical site can decrease the risk of side effects caused by oral radiation. The researchers will also find out if this approach affects the rate of disease coming back after treatment (recurrence), and will measure participants' quality of life by having them complete questionnaires.

Inclusion Criteria:

• Age ≥ 18

• Surgical resection of all gross disease without evidence of residual loco-regional disease on simulation PET/CT.

• pT1-2, or pT3 by DOI, pN0-2b Squamous Cell Carcinoma of the Oral Tongue confirmed on final surgical pathology. Patients must have:

  • at least two of the following pathologic risk features

    • LVI
    • DOI ≥ 4mm and ≤ 10mm OR

  • 1 or 2 pathologically positive nodes N1 to low volume N2b. OR DOI >10 mm OR

  • <=cT3N2b who undergo induction with near pCR (<5% viable) or pCR at primary site

• Primary specimen surgical margins ≥3 mm (if <WPOI 5, margin can be >= 2.2mm)

• Signed informed consent form by the participant or their legally authorized representative (LAR)

Exclusion Criteria:

• N2c/N3 nodal disease
• pT3 by size
• >2 pathologically positive nodes
• Primary specimen surgical margin < 3 mm (if <WPOI 5, margin can be >= 2.2mm)
• Extensive Perineural Invasion (PNI); non-extensive PNI is permitted.
• Extra-capsular extension in any pathologically positive lymph node
• Prior or simultaneous invasive malignancy that, in the opinion of the PI, represents a competing risk of death equivalent to the patient's oral tongue squamous cell carcinoma.
• Auto-immune conditions that would otherwise preclude radiation in the opinion of the PI (e.g. Scleroderma).
• Lack of ability to understand and willingness to sign a written informed consent and complete questionnaires.

Memorial Sloan Kettering Cancer Center supports the international committee of medical journal editors (ICMJE) and the ethical obligation of responsible sharing of data from clinical trials. The protocol summary, a statistical summary, and informed consent form will be made available on clinicaltrials.gov when required as a condition of Federal awards, other agreements supporting the research and/or as otherwise required. Requests for deidentified individual participant data can be made beginning 12 months after publication and for up to 36 months post publication. Deidentified individual participant data reported in the manuscript will be shared under the terms of a Data Use Agreement and may only be used for approved proposals. Requests may be made to: crdatashare@mskcc.org.