What type of delivery method does Tc sulfur colloid for lymphoscintigraphy utilize?

• A. Intravenous delivery
• B. Intradermal delivery
• C. Inhalation delivery
• D. Buccal delivery

Answer: (B)

Tc sulfur colloid for lymphoscintigraphy is administered using intradermal delivery. This method involves injecting the radiopharmaceutical directly into the dermal layer of the skin, allowing it to migrate into the lymphatic system. This technique is particularly effective in imaging lymph nodes and assessing lymphatic drainage, which is crucial for procedures such as sentinel lymph node biopsies.

Intradermal delivery ensures that the radiotracer is placed at the appropriate site where lymphatic uptake can occur, providing the best visualization of lymph function and anatomy. This is essential for accurate diagnostic purposes, especially in the evaluation of certain types of cancers where lymphatics play a pivotal role.

Other methods of delivery, such as intravenous or inhalation, are not suitable for the purpose of lymphoscintigraphy because they would not target the lymphatic system effectively. Buccal delivery is also not relevant in this context, as it refers to medications administered via the oral mucosa, which does not facilitate lymphatic imaging. Thus, intradermal delivery is the correct and most effective method for the use of Tc sulfur colloid in lymphoscintigraphy.