111In-octreotide is superior to 123I-metaiodobenzylguanidine for scintigraphic detection of head and neck paragangliomas.
In this study, we evaluated the diagnostic yield of somatostatin receptor scintigraphy (SRS), I-metaiodobenzylguanidine (MIBG) scintigraphy, and morphologic imaging (CT or MRI) in patients with head and neck paragangliomas.


METHODS
In a university hospital setting, patients considered to have head and neck paraganglioma were referred to the outpatient endocrinology department and underwent CT or MRI, SRS, and MIBG imaging. For validation, we used a composite reference standard consisting of clinical and histologic data and CT or MRI, with which SRS and MIBG imaging were compared. Urinary metanephrine and normetanephrine measurements were also obtained.


RESULTS
Twenty-nine consecutively referred patients (17 women and 12 men) were included and were found to have paraganglioma. Both morphologic and SRS were positive in 27 patients (sensitivity, 93%, and 95% confidence interval [CI], 77%-98%, compared with the composite reference standard), whereas MIBG was positive in only 13 patients (44%; 95% CI, 23%-61%) (P < 0.001, compared with SRS). On a lesion-based analysis, morphologic imaging detected 31 lesions (sensitivity, 82%; 95% CI, 65%-92%), SRS detected 34 (89%; 95% CI, 75%-97%), and MIBG detected 15 (42%; 95% CI, 26%-59%). SRS was superior to MIBG (P = 0.001). With SRS, a previously unknown carcinoid tumor was detected in 1 patient, and a carcinoid was suspected in another patient. MIBG detected an additional adrenal pheochromocytoma in 1 patient. Urinary metanephrine or normetanephrine excretion was elevated in 6 patients. The number of lesions on SRS and MIBG per patient correlated with the levels of abnormal metanephrine or normetanephrine excretion (P = 0.005 and P = 0.02, respectively).


CONCLUSIONS
SRS was superior to MIBG in patients with highly suspected head and neck paraganglioma.
Koopmans
Klaas Pieter
KP
Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Jager
Pieter L
PL
Kema
Ido P
IP
Kerstens
Michiel N
MN
Albers
Frans
F
Dullaart
Robin P F
RP
D019797:3-Iodobenzylguanidine; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging*; D006801:Humans; D007205:Indium Radioisotopes; D007457:Iodine Radioisotopes; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015282:Octreotide / Q000031:analogs & derivatives; D010235:Paraganglioma / Q000000981:diagnostic imaging*; D017481:Receptors, Somatostatin / Q000378:metabolism; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed
D007205:Indium Radioisotopes; D007457:Iodine Radioisotopes; D017481:Receptors, Somatostatin; C094279:indium-111-octreotide; D019797:3-Iodobenzylguanidine; D015282:Octreotide