Clinical impact of somatostatin receptor scintigraphy in the management of paragangliomas of the head and neck.

UNLABELLED: Paragangliomas are neuroendocrine tumors expressing somatostatinergic receptors and, thus, may be imaged by somatostatin receptor scintigraphy (SRS). The purpose of the study was to assess the contribution of SRS in the management of paraganglioma of the head and neck.
METHODS: (111)In-Pentetreotide (148 MBq) was intravenously administered to 3 groups of patients. Group A consisted of 9 patients with tumors of the head and neck that did not exhibit typical radiologic features of paragangliomas and required further diagnostic evaluation. Group B consisted of 28 patients with known paragangliomas or paraganglioma metastatic lymph node who required staging and assessment of multicentricity. Group C consisted of 5 asymptomatic relatives of affected individuals who required screening. All patients underwent clinical, laboratory, radiologic, and audiovestibular evaluation.
RESULTS: In group A (n = 9), SRS was positive in 6 cases, 4 paragangliomas and 2 meningiomas, and negative in 3 patients in whom the initial diagnosis of paraganglioma was excluded. In group B (n = 28), SRS was strongly positive in all of the 34 head and neck masses diagnosed on conventional imaging to be paragangliomas; it localized 1 primary malignant paraganglioma and revealed 9 unexpected foci. In group C (n = 5), SRS was positive in 3 of the 5 relatives, CT or MR scan confirming the diagnosis of paraganglioma in all cases.
CONCLUSION: Because of very high sensitivity in detecting paraganglioma, SRS should be included in a multiple-step strategy for patients' management. It could be useful in ruling out the diagnosis of schwannoma, but its major advantage may involve patients' staging. Once biologic genetic testing of affected patients' relatives evidenced the predisposing mutation, SRS could be proposed to identify individuals who express the disease.