99mTc FAPI

Technetium-99m labeled fibroblast activation protein inhibitors (99mTc FAPI) are radiopharmaceutical tracers designed for single photon emission computed tomography (SPECT) imaging. These compounds specifically target the fibroblast activation protein (FAP), which is highly expressed in cancer-associated fibroblasts within the tumor microenvironment and in fibrotic tissues, but minimally present in normal tissues. By binding to FAP, these tracers enable sensitive and specific imaging of tumors and sites of fibrosis or inflammation. Several labeling strategies have been developed, including HYNIC-based derivatives such as 99mTc-HYNIC-FAPI04 and 99mTc-HFAPi, which demonstrate high radiochemical purity (>95%), strong affinity for human and murine FAP, excellent tumor uptake, favorable pharmacokinetics, and low toxicity profiles. Clinical studies show that SPECT/CT with these agents can outperform conventional imaging modalities like contrast-enhanced CT for detecting metastases—especially in liver and lymph nodes—and can be used to assess a range of cancers (gastrointestinal tumors, gliomas, lung cancer, breast cancer) as well as non-oncologic conditions such as idiopathic pulmonary fibrosis[1][2][4][5][6][7].

Other names

technetium-99m labeled fibroblast activation protein inhibitortechnetium99m labeled fibroblast activation protein inhibitortechnetium 99m labeled fibroblast activation protein inhibitortechnetium Tc 99m FAP inhibitor