Octreotide scintigraphy in the head and neck

Octreotide is a somatostatin analogue that, when coupled to a radioisotope, produces a scintigraphic image of neuroendocrine tumors (NET) expressing somatostatin type 2 receptors (SSR 2). Octreotide scintigraphy (OS) may be useful in confirming the preoperative diagnosis of certain head and neck NET. Paragangliomas (PG), like many NET, have been found to have a high density of SSR 2 on the cell surfaces. Other NET of the head and neck include merkel cell carcinomas (MCC), medullary thyroid carcinomas (MTC), and esthesioneuroblastomas.

A retrospective study that compared the results of OS with the histopathologic diagnosis in 74 patients with head and neck NET.

Of the 60 patients undergoing evaluation for suspected paraganglioma, OS was correctly positive in 36 of the 37 patients with PG. OS was correctly negative in 19 of the 23 patients that did not exhibit PG. For PG, this yielded a sensitivity of 97% and a specificity of 82%. There were 14 patients in the nonparaganglioma group. OS detected or diagnosed all metastases in three patients with MTC, locoregional recurrences in two patients with esthesioneuroblastoma, an extrapituitary adenoma in one patient, and metastasis in two patients with MCC. It failed to detect a paraspinal metastasis in the third patient with MCC.

On the basis of this series of patients, OS appears to be a reliable test to detect PG and may be helpful in detecting primary and metastatic disease for NET.