Which radiopharmaceutical is commonly used for lymphatic imaging?

• A. Tc HMPAO
• B. Tc tilmanocept
• C. F-18 FDG
• D. I-123 MIBG

Answer: (B)

The use of Tc tilmanocept in lymphatic imaging is due to its specific design and mechanism of action. This radiopharmaceutical is a targeted agent that binds to the mannose receptor found on macrophages, which are abundant in lymphatic tissues. When administered, Tc tilmanocept can effectively highlight the lymphatic system during diagnostic imaging procedures.

This selective targeting allows for improved visualization of lymphatic pathways and lymph nodes, which is crucial in assessing conditions such as lymphedema, lymph node involvement in cancer, or sentinel lymph node mapping. The use of this agent enhances the accuracy and effectiveness of lymphatic imaging, making it the preferred choice in this context.

Other options, while useful in various imaging modalities, do not have the same specificity for lymphatic structures as Tc tilmanocept does. For example, Tc HMPAO is primarily used for brain imaging and assessing blood flow, while F-18 FDG is mainly used in oncological studies to evaluate metabolic activity in tumors. I-123 MIBG is utilized primarily in neuroendocrine tumor imaging and does not serve the lymphatic system specifically. Thus, Tc tilmanocept stands out as the choice specifically tailored for lymphatic imaging.