Phase I/II, Open-Label Study Evaluating the Efficacy and Pharmacokinetics of Panitumumab-IRDye800 as an Optical Imaging Agent to Detect Neoplasms During Neurosurgical Procedures

Inclusion Criteria: 1\) One of the following: 1. Cohorts 1, 2, and 3: Participants with suspected or confirmed diagnosis of glioblastoma 2. Cohort 4: Participants with suspected or confirmed diagnosis of vestibular schwannoma 2.) Planned surgical removal of the tumor as part of standard of care. This may include participants postchemotherapy, post-radiation, and/or participants who have undergone diagnostic biopsy for their original diagnosis and are felt to be candidates for resection. 3\) Participant age ≥ 18 years. 4\) Participants or their designated advocates must be willing to and capable of providing informed consent and willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations, and other study procedures. Exclusion Criteria: 1. Received an investigational drug within 30 days prior to first dose of Panitumumab-IRDye800. 2. Myocardial infarction (MI); cerebrovascular accident (CVA); uncontrolled congestive heart failure (CHF); significant liver disease as determined by PI; or unstable angina within 6 months prior to enrollment. 3. History of infusion reactions to monoclonal antibody therapies 4. Pregnant or breastfeeding. 5. Evidence of QTc prolongation on pretreatment ECG (greater than 440 ms in males or greater than 460 ms in females). 6. Any of the following lab values: 1. Platelet count \< 75,000/mm3 2. TSH ≥ 13 micro International Units/mL. 3. Magnesium, potassium, or calcium \< each respective upper limit of normal 4. Serum creatinine \> 1.5 times upper limit of normal 7. Participants receiving Class IA (quinidine, procainamide) or Class III (dofetilide, amiodarone, sotalol) antiarrhythmic agents. 8. Participants with a history or evidence of interstitial pneumonitis or pulmonary fibrosis. 9. Participants not deemed by PI to be appropriate candidates for optimal resection of tumor based on location, involvement of eloquent brain, satellite lesions, or other factors not specifically listed here.