Ommaya Reservoir Placement at the Time of Biopsy for Longitudinal Biomarker Collection in Patients With Brain Tumors

Inclusion Criteria: * Clinical and radiographic evidence suggesting a diagnosis of a brain tumor * Planned biopsy for suspected or previously diagnosed brain tumor as part of routine clinical care at Mayo Clinic (Rochester, Minnesota \[MN\]) * Willingness of the patient to provide informed consent * Patient is willing to have their Ommaya sampled on at least 2 future occasions * Patients is willing to have CSF banked through the neuro-oncology biorepository (requires a separate signature) Exclusion Criteria: * Vulnerable populations including pregnant women, prisoners, and individuals \< 18 years old * Patients who are not appropriate candidates for biopsy due to current or past medical history or uncontrolled current illness * Prior history of any wound infection * Any patient who the surgeon feels is not an optimal candidate for Ommaya reservoir placement. Such reasons may include, but will not be limited to, surgical anatomy, clinical evidence of immunosuppression, and/or elevated risk of wound infection due to diabetes, smoking history, morbid obesity, or any other concerns