111Indium pentetreotide scan detection of familial paragangliomas

Approximately 10% of head and neck paragangliomas are familial. Magnetic resonance imaging (MRI) is reported to be the best method for screening these families. 111Indium pentetreotide (Octreoscan) scintigraphy has been shown to be a sensitive indicator of neural crest tumors such as paragangliomas. Early diagnosis and treatment of familial paragangliomas (FP) would decrease the morbidity of tumor excision. Patients from two kindred with FP were scanned 24 hours after intravenous injection with approximately 6 millicuries of 111Indium pentetreotide. The entire body was imaged. Areas of increased uptake were further imaged with MRI. Altogether, five patients had positive 111Indium pentetreotide scans. Two unsuspected glomus tympanicums and bilateral carotid body tumors were identified. Three people tested had no abnormal uptake. There were no untoward reactions to the nuclide. 111Indium pentetreotide scanning is a safe, noninvasive method for early diagnosis of FP and is useful in detecting multicentric lesions. Patients suspect for FP are undergoing 111Indium pentetreotide imaging and followed up with MRI of the involved site if positive.