A Study of Radiation Therapy After Surgery in People With Oral Tongue Squamous Cell Carcinoma

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.