Inclusion Criteria:

• 1. Adult patients 18 years of age and older
• 2. Patients presenting with a nervous system tumor presumed to be resectable and at risk for local recurrence on pre-operative assessment
• 3. Good operative candidates, as determined by the treating physician and multidisciplinary team
• 4. Subjects capable of giving informed consent

Exclusion Criteria:

• 1. Pregnant women, as determined by urinary or serum beta hCG within 48 hours of surgery
• 2. Subjects with a history of iodide allergies
• 3. Vulnerable patient populations
• 4. Patients unable to participate in the consent process
• 5. Patients with history of uncontrolled HTN (requiring ER admission or ≥ 3 BP medications)