Serial Magnetic Resonance Imaging for the Prediction of Radiation-Induced Changes in Normal Tissue of Patients With Oral Cavity or Skull Base Tumors

Inclusion Criteria: All Cohorts: * Patients older than 18 years of age * Patients with good performance status (ECOG score 0-2) * Patients willing to give written informed consent. Cohort 1 (Individuals without ORN or MRONJ): * Patients with histologically proven malignant neoplasms of the oral cavity, oropharynx or skull base. * Patients currently dispositioned to treatment with radiotherapy and/or antiresorptive or antiangiogenic medication therapy Cohort 2 (Individuals with ORN or MRONJ): * Patients with a clinical diagnosis of ORN or MRONJ following treatment for cancer * Patients previously dispositioned to treatment with radiotherapy and/or antiresorptive or antiangiogenic medication therapy Exclusion Criteria: * Patients unable to tolerate DW-MRI or DCE-MRI or having an estimated GFR \< 30ml/min/1.73m2. * Patients with contraindication to MRI (e.g. non-MRI compatible metallic implants)