Octreotide Scintigraphy for the Detection of Paragangliomas

Abstract

Paragangliomas are neuroendocrine tumors located primarily in the head and neck region, but they can also occur at other sites. Confirming the preoperative diagnosis and detecting synchronous tumors may be difficult in some patients. Octreotide is a somatostatin analog that, when coupled to a radioisotope, produces a scintigraphic image of tumors expressing somatostatin type 2 receptors. Paragangliomas, like many neuroendocrine tumors, have been found to have a high density of somatostatin type 2 receptors on the cell surface. This study compared the results of preoperative octreotide scintigraphy with the histopathology in 21 patients who underwent surgery for presumed head and neck paragangliomas. Octreotide scan findings were positive in 16 patients with paragangliomas and negative in 3 patients with other pathology. One false-positive and 1 false-negative result were obtained. Thus, this test had an accuracy of 90%, a sensitivity of 94%, and a specificity of 75%. Previously unidentified synchronous tumors were identified in 5 patients. On the basis of this series of patients, octreotide scintigraphy appears to be a reliable test to detect paragangliomas and may be quite helpful in preoperative planning.

The influence of Ki-67 proliferation index on Tc-99m-EDDA-HYNIC-TOC somatostatin receptor scintigraphy in patients with carcinoids

“…Furthermore, In-111-octreotide has become the gold standard in diagnosing NETs in various locations [21][22][23][24][25][26][27][28]. However, poor physical properties of In-111 have triggered intense efforts to synthesize somatostatin analogues which can be labeled with Tc-99m, for the purpose of achieving better image quality, smaller expositional radiation doses per patient, and ready availability [29,30].…”

Complex Glomus Jugulare Tumor: Management Issues

“…Radiolabelled octreotide has been shown to have a detection rate of 67-91% for all neuroendocrine tumours but is of low specificity as uptake is also demonstrable in many other tumours, granulomas and autoimmune diseases [12]. An accuracy rate of 90%, a sensitivity rate of 94%, and specificity of 75% has been reported [13]. Newer somatostatin receptor agents such as Ga68-DOTANOC show promise of improved sensitivity because of its high affinity for subtypes 2 and 5 (SSTR2, SSTR5) [14].…”

Nasopharynx paraganglioma with extension in the clivus

“…The presence of somatostatin receptors in paraganglioma has been used recently for radionuclear imaging. Pentetreotide, a radiolabelled octreotide, has been shown to exhibit high sensitivity (above 90%) for paragangliomas bigger than 1 cm [9,19]. The specificity is a little lower because other neuroendocrine tumors also exhibit somatostatin receptors.…”