Diagnosis of Metastatic Tumors on 68Ga-FAPI PET-CT and Radioligand Therapy With 177Lu-EB-FAPI

Fibroblast activation protein (FAP) is a serine peptidase on the surface of tumor associated fibroblasts. It belongs to type II transmembrane glycoprotein. It is rich and characteristic expressed in tumor associated fibroblasts. It has special biological characteristics and stable genome. FAP is expressed at a high level in mesenchymal cells during the embryonic period and is inhibited shortly after birth. It is usually not expressed or expressed at a low level in the resting tissues of normal adults, but it is highly expressed in diseases related to tissue repair and matrix reconstruction, such as wound healing, inflammatory response, fibrosis and cancer It plays an important role in metastasis and immunosuppression.Currently, 68Ga labeled FAPI (68Ga-FAPI) has been successfully applied to a variety of tumor PET/CT imaging, including lung cancer, breast cancer, and gastrointestinal tract tumors.By modifying FAPI with Evans blue (EB) to form a new EB-FAPI, endogenous albumin can be used as a reversible carrier to prolong the retention time of drugs in the blood, thus increasing the targeted aggregation and retention of 177Lu-EB-FAPI in tumor cells, and effectively killing a variety of transplanted tumors with positive FAP expression.we'll try to assess the safety and therapeutic response to 177Lu-EB-FAPI in patients with metastatic tumors in human.