Using Fluorine-18-Labeled Fluoro-Misonidazole Positron Emission Tomography To Detect Hypoxia in Head and Neck Cancer Patients

Inclusion Criteria for Cohort 1 and Cohort 2 : * Histologically confirmed diagnosis of head and neck carcinoma (excluding nasopharynx, paranasal sinus, salivary, and thyroid malignancies)Any unknown primary squamous cell carcinoma of head and neck with gross nodes is allowed (2002 AJCC) * 18 years of age or older * Must not have received prior radiation therapy or chemotherapy for this diagnosis. Patients who have had their primary site tumor removed by surgery but still present with grossly enlarged lymph nodes are eligible for this study. * Karnofsky performance status ≥ 70. Exclusion Criteria for Cohort 1 and Cohort 2: * all nasopharyngeal, paranasal sinus, salivary cancer, and thyroid malignancies * prior chemotherapy or radiotherapy within the last three years * patients that underwent previous surgical resection for the same disease (except for biopsy or surgery removing primary site tumor but still present with grossly enlarged lymph nodes) * any prior radiotherapy to the head and neck region * pregnant (confirmed by serum b-HCG in women of reproductive age) or breast feeding Subject Exclusion Criteria for Optional Contrast MRIs • Subjects with a known contraindication to the standard MRI contrast agent (Gadavist, a gadolinium-based contrast agent) and/or a recent estimated glomerular filtration rate (eGFR) of 30 or less will be excluded from all DCE-MRIs, and will instead receive non-contrast MRIs at the DCE-MRI time points.