This study is to collect data about how 18FPARPi can be used together with PET/positron emission tomography and MRI/magnetic resonance imaging scans to take pictures of brain cancer

Inclusion Criteria:

• Patients with new or suspected recurrent brain tumors (including suspected recurrent brain tumors showing growth from any preceding scan)
• Age >/= 18 years
• Minimum at least one brain lesion size >/= 1.5cm diameter
• Scheduled to undergo treatment at MSK
• Willingness to sign informed consent
• Able to receive intravenous gadolinium contrast per MSK Department of Radiology guidelines

Exclusion Criteria:

• Any contraindication to 3T MRI (PET/MR scanner is 4.0 Tesla)
• Pregnancy or breast-feeding women

Memorial Sloan Kettering Cancer Center supports the international committee of medical journal editors (ICMJE) and the ethical obligation of responsible sharing of data from clinical trials. The protocol summary, a statistical summary, and informed consent form will be made available on clinicaltrials.gov when required as a condition of Federal awards, other agreements supporting the research and/or as otherwise required. Requests for deidentified individual participant data can be made beginning 12 months after publication and for up to 36 months post publication. Deidentified individual participant data reported in the manuscript will be shared under the terms of a Data Use Agreement and may only be used for approved proposals. Requests may be made to: crdatashare@mskcc.org.