Selective Avoidance of Nodal VolumEs at Minimal Risk (GCC 20110)

Inclusion criteria

• ✓. Is there pathologically (histologically or cytologically) proven diagnosis of p16+ squamous cell carcinoma (including the histological variants papillary squamous cell carcinoma and basaloid squamous cell carcinoma) of the oropharynx (tonsil or base of tongue)? Note: Cytologic diagnosis from a cervical lymph node (from a paraffin block, not from smears) is sufficient in the presence of clinical evidence of a primary tumor in the oropharynx. Clinical evidence should be documented, may consist of palpation, imaging, or endoscopic evaluation, and should be sufficient to estimate the size of the primary (for T stage).
• ✓. Does the patient require elective contralateral radiotherapy in the definitive or adjuvant setting (i.e. base of tongue primary or tonsil with base of tongue invasion, soft palate invasion, or medialized as defined by \> 1/3 of the distance from the tonsil to the midline of the soft palate?
• ✓. Does the patient have clinical stage T1-4, N0, N1 or N3, and M0 disease (AJCC 8th edition) as defined by physical examination and appropriate imaging (PET/CT preferred, CT neck with IV contrast with CT chest without contrast as recommended alternative to PET/CT)?
• ✓. Was a general history and physical examination performed by a radiation oncologist, medical oncologist, or head and neck surgeon within 60 days prior to registration?
• ✓. Was the patient's Zubrod Performance Status 0-1 within 30 days prior to registration?
• ✓. Is the patient ≥ 18 years of age?
• ✓. For women of childbearing potential, was a serum pregnancy test completed within 2 weeks of initiation or radiotherapy?
• ✓. If yes, was the serum pregnancy test negative?

Exclusion criteria