Investigational Scans (Amide-CEST MRI and 18F-Fluciclovine PET/MRI) for the Imaging of Brain Metastases in Patients Receiving Immunotherapy
This clinical trial studies whether amide proton transfer (amide)-chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) and 18F-fluciclovine positron emission tomography (PET)/MRI scans can be used to identify cancer that has spread from where it first started (primary site) to the brain (brain metastases) in patients receiving immunotherapy. MRI is a procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body. These pictures can show the difference between normal and diseased tissue. MRI is the standard imaging approach for managing patients with brain metastases. Imaging findings during immunotherapy can change throughout treatment and it can be difficult to determine if the changes are due to the treatment or due to the brain tumor increasing in size or returning. Amide-CEST MRI is a type of MRI that uses differences in the tissue microenvironment, like protein concentration, to generate contrast differences. A PET scan is a procedure in which a small amount of a radioactive drug (18F-fluciclovine) is injected into a vein, and a scanner is used to make detailed, computerized pictures of areas inside the body where the 18F-fluciclovine is taken up. This is combined with an MRI scan to overlay activity data onto detailed anatomic images. Amide-CEST MRI and 18F-fluciclovine PET/MRI may be more effective in identifying brain metastases in patients receiving immunotherapy.