Fibroblast activation protein (FAP) is a type II transmembrane glycoprotein expressed on the surface of cancer-associated fibroblasts (CAFs) in the stroma of various tumor entities. Recently, radiolabeled molecules targeting the FAP, called FAP inhibitors (FAPI) labelled with Gallium-68, have been developed for molecular imaging with PET/CT (positron emission tomography/computed tomography). This radiotracer often presents a higher cancer lesion detectability than F18-FDG (fluorodeoxyglucose), partly thanks to its higher tumour-to-background ratio achieved by a low background activity, particularly in the brain, abdominal cavity and liver. These advantages have resulted in a superior sensitivity of Ga68-FAPI PET/CT over F18-FDG and higher SUV (standardized uptake value) in evaluating various types of cancer. In this context, Ga68-FAPI PET/CT seems promising to further study as a clinical imaging modality for preoperative assessment of peritoneal carcinomatosis.
In this study, the investigators correlate Ga68-FAPI PET/CT findings in terms of peritoneal involvement with intraoperative findings based on histopathology and try to find out how accurate Ga68-FAPI PET/CT is for the preoperative assessment of peritoneal carcinomatosis.