This study is testing a special scan called 68Ga-PSMA-11 PET/CT. This scan helps doctors see how active a brain tumor is. It’s for adults who have brain tumors called high-grade glioma (HGG) or brain metastases, which means cancer has spread to the brain from another part of the body.

Participants must be at least 18 years old and have a brain tumor that is either suspected or confirmed. They should be planning to have a biopsy, which is when a small piece of the tumor is taken out to study. The lesion (tumor area) must be at least 1 cm in size. People who cannot handle tight spaces or have certain medical implants might not be able to join. Pregnant women or those who are nursing cannot participate.

• The study involves undergoing a special scan to see tumor activity.
• Participants need to be able to have a biopsy or surgery planned.
• People with certain health issues or allergies may not be eligible.