99m Tc-FAPI-46

Technetium-99m labeled FAPI-46 (99m Tc-FAPI-46) is a radiopharmaceutical tracer designed for SPECT imaging of tumors by targeting the fibroblast activation protein (FAP), which is highly expressed on cancer-associated fibroblasts in the stroma of most solid tumors. FAP inhibitors like FAPI-46 enable visualization of tumor microenvironments with high specificity and low background uptake, making them valuable for oncologic imaging. 99m Tc-FAPI tracers have demonstrated favorable tumor-to-background ratios and may outperform traditional tracers such as ^18F-FDG PET/CT in certain cancers, including mucinous breast cancer. The compound shares similar characteristics to other FAP-targeted agents like ^68Ga-FAPI but uses technetium‑99m, which is more widely available for SPECT than PET isotopes[6][9][2]. Preclinical studies show that derivatives of 99m Tc-labeled FAPI‑46 exhibit good stability, hydrophilicity, and high affinity for FAP with significant tumor uptake and improved pharmacokinetics compared to earlier generations[1][4]. Clinical case reports highlight its utility in detecting primary tumors and metastases across various malignancies.

Other names

technetium-99m labeled FAPI-46technetium99m labeled FAPI-46technetium 99m labeled FAPI-46[99mTc]Tc-FAPI-46