Octreotide scintigraphy

Last revised by Yahya Baba on 1 Sep 2023

Octreotide scintigraphy uses 111In-labeled octreotide, which is a somatostatin analog; it is also known as Octreoscan, a brand name for 111In-labeled pentetreotide. Pentetreotide is a DTPA-conjugated form of octreotide, originally manufactured by Mallinckrodt Nuclear Medicine LLC, which now forms part of Curium. 

The radiotracer is characterized by a high affinity of bond with the somatostatin receptor 2 (SST2). It penetrates inside the cell by endocytosis, first held by lysosomes and then transferred to the nucleus 4,5.

It is particularly useful for the assessment of neuroendocrine tumors, and the Krenning Score is used to grade these, most commonly for peptide receptor radionuclide therapy (PRRT) planning. 

Examples include:

Certain non-neuroendocrine tumors can also show uptake in an Octreoscan. Examples include:

Also, certain autoimmune or granulomatous diseases (for example sarcoidosis) may occasionally show octreotide uptake by overexpression of somatostatin receptors 6-8.

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