18F-FAPI-74 PET/CT Compared to 18F-FDG PET/CT for the Assessment of Metastatic Invasive Lobular Breast Cancer
This phase II trial compares positron emission tomography (PET)/computed tomography (CT) imaging using a tracer called 18F-FAPI-74 versus the standard 18F-FDG tracer for the assessment of invasive lobular breast cancer that has spread from where it first started (primary site) to other places in the body (metastatic). A PET scan is a procedure in which a small amount of an imaging agent is injected into a vein, and a scanner is used to make detailed, computerized pictures of areas inside the body where the tracer is taken up. Because tumor cells often take up more tracer than normal cells, the pictures can be used to find tumor cells in the body. CT scan is a procedure that uses a computer linked to an x-ray machine to make a series of detailed pictures of areas inside the body. The pictures are taken from different angles and are used to create 3-dimensional views of tissues and organs. Combining a PET scan with a CT scan can help make the image easier to interpret. PET/CT scans are hybrid scanners that combine both modalities into a single scan during the same examination. Some tumors have special cells called cancer-associated fibroblasts. These cells have a protein called fibroblast activation protein (FAP), which helps cancer grow and spread. The new 18F-FAPI-74 PET scan uses a special small molecule that sticks to FAP protein, so doctors can see these cells in and around tumors anywhere in the body. 18F-FAPI-74 PET/CT may be more effective than 18F-FDG PET/CT for the assessment of metastatic invasive lobular breast cancer.