Characterizing Histiocytosis With 68Ga-FAPI PET/CT

Histiocytic disorders are rare diseases that are characterized by tissue infiltration of histiocytes (dendritic cells) and other inflammatory white blood cells.68Ga-FAPI has been developed as a tumor-targeting agent as fibroblast activation protein is overexpressed in cancer-associated fibroblasts and it might be a pan-tumor PET agent.Recent discoveries have shown that inflammation and fibrosis secondary to mutated histiocytes, rather than a proliferative cell mechanism, result in manifestation of the disease.Thus, the investigators aim to carry out this prospective study to investigate the role of 68Ga-FAPI PET/CT in the diagnosis, therapy response assessment and follow-up of histiocytosis.