Molecular Imaging of FAP Expressing Cancer-associated Fibroblasts in NSCLC Treated With Immune-checkpoint Inhibitors

Fibroblast activation protein (FAP), a type II membrane glycoprotein, is selectively expressed by cancer-associated fibroblasts (CAFs) in more than 90% of epithelial carcinomas. FAP also regulates antitumor immune response. For these reasons, FAP is an attractive target and molecular imaging biomarker to assess CAFs and the tumour's landscape before and during immunotherapy. The PET radiotracer 68Ga-FAPI (Fibroblast activation protein inhibitor) allows the visualisation and quantification of CAFs.This study will use a non-invasive technique to assess CAFs before and during immunotherapy and to evaluate diverse predictive biomarkers in a prospective setting studying simultaneously CAFs (using 68Ga-FAPI) and cfDNA.