18F-Fluciclovine PET/CT in Multiple Myeloma

Background: Multiple myeloma (MM) is an incurable cancer of certain blood cells. MM often returns after treatment, and most people survive only 5 to 8 years after diagnosis. To improve survival, researchers need to find ways to identify returning disease earlier. Objective: To find out if the radiotracer 18F-fluciclovine (a substance injected into the blood during imaging scans) is better at detecting MM than the one (18F-FDG) currently used for this purpose. Eligibility: Adults aged 18 years or older with MM. The MM may be newly diagnosed (NDMM); or it may have returned or failed to respond after at least 1 prior line of treatment (RRMM). Design: Participants will be screened. They will have blood tests. They will have a positron emission tomography (PET) or computed tomography (CT) scan using 18F-FDG. The radiotracer will be injected into a vein. Then participants will lie on a table while the PET/CT scan takes images of their body. All participants will have 3 study visits. During each visit they will have: Two PET/CT scans. One with 18F-FDG, one with 18F-fluciclovine. An optional magnetic resonance imaging scan. A bone marrow biopsy. An area on the hip will be numbed; a needle will be inserted to draw out a sample of the soft tissue from inside the bone. These tests may be spread over 30 days for each visit. NDMM participants will have their second study visit 2 to 4 weeks after they complete their usual treatment for the disease. RRMM participants will have their second visit 6 months after their first. All participants will have a third study visit after 5 years or when their disease progresses.