Where does 111In-pentetreotide normally localize within the human body?

111In-pentetreotide is a radiopharmaceutical that binds to somatostatin receptors, which are found in various tissues throughout the body. Its primary localization occurs in areas rich in somatostatin receptors, particularly in neuroendocrine tissues.

The salivary glands are known to express a significant number of these receptors, making them one of the most prominent sites for accumulation of 111In-pentetreotide. This localization is clinically relevant, especially in imaging and diagnosing tumors that have a neuroendocrine component, as these tumors often overexpress somatostatin receptors.

In contrast, while the thyroid gland, spleen, and pituitary gland may have some expression of somatostatin receptors, they do not have the same level of receptor density or clinical relevance for 111In-pentetreotide imaging. This distinction highlights why salivary glands are the primary site of localization for this particular radiopharmaceutical.