What is the filtered administration method for Tc Sulfur Colloid in lymphoscintigraphy?

• A. Intravenous
• B. Intradermal or subcutaneous
• C. Oral ingestion
• D. Intramuscular injection

Answer: (B)

The filtered administration method for Tc Sulfur Colloid in lymphoscintigraphy is effectively achieved through intradermal or subcutaneous injection. This method allows the radiopharmaceutical to be deposited directly into the tissues where the lymphatic vessels can efficiently transport the tracer.

Using the intradermal or subcutaneous route is critical because it ensures that the colloid is introduced close to the lymphatic vessels of interest. This is particularly important in lymphoscintigraphy, which is designed to visualize the lymphatic system and assess lymphatic function. By injecting under the skin, the technetium-labeled sulfur colloid can migrate through the lymphatics, enabling accurate imaging and evaluation of lymphatic drainage patterns.

Other administration routes such as intravenous, oral ingestion, and intramuscular injection are not suitable for this specific application. Intravenous administration typically distributes the pharmaceutical through the bloodstream rather than targeting the lymphatic system, which would compromise the study's primary objective. Oral ingestion is not applicable as it would not allow for direct lymphatic uptake, while intramuscular injection would deposit the compound in muscle tissues rather than the lymphatic networks required for accurate lymphoscintigraphic imaging.