Personalized Ultrafractionated Stereotactic Adaptive Radiotherapy for Palliative Head and Neck Cancer Treatment (PULS-Pal)

Inclusion Criteria: * \>= 18 years old * Diagnosis of primary or recurrent, localized or metastatic (American Joint Committee on Cancer (AJCC) 8th Edition stages I-IV) head and neck cancer. In primary diagnosis cases, pathologic confirmation is required. In recurrent and/or metastatic diagnosis cases, pathologic confirmation is not required if not beneficial to the patient as standard of care, and diagnosis can be assumed based on clinical and/or radiographic evidence * Ineligible for or declines standard of care definitive treatment(s), which will be documented in the patient's trial screening progress note in their electronic medical record by the treating physician * Measurable disease within the head and/or neck clinically and/or on imaging studies (CT, PET, MRI) within 30 days from date of enrollment * Patient maximum tumor(s) or tumor bed diameter must be less than 10cm * In a woman of childbearing potential, a negative serum or urine pregnancy test within 1 week of treatment start must be documented. Women of childbearing potential must agree to use adequate contraception (hormonal or barrier method of birth control; or abstinence) for duration of study participation and for up to 4 weeks following the study treatment * Patients with a tracheostomy and/or a percutaneous endoscopic gastrostomy tube are eligible for inclusion Exclusion Criteria: * Pregnant or breast-feeding * More than 1 prior radiation treatment course directed to the treatment area over the patient'…