Paragangliomas have neuroendocrine characteristics. We previously described successful in vivo visualization of various
tumors of neuroendocrine origin after injection of the radiolabeled
somatostatin analogue
octreotide. In this study, we report the results of
111In-octreotide scintigraphy in 34 patients referred because of known
paragangliomas or in whom a
paraganglioma was suspected and compared the results of
octreotide scintigraphy with the outcomes of other imaging techniques used in the diagnosis or follow-up of these patients. Fifty of 53 (94%) known localizations in 25 patients with
paragangliomas were visualized. In two patients, three localizations were missed during
octreotide scintigraphy. Unexpected additional
paraganglioma sites, not detected or not investigated with conventional imaging techniques, were found in 9 of 25 patients (36%) with known
paragangliomas. In four of them, the supposed
tumor localizations were thereafter also demonstrated with other imaging modalities. In eight of nine patients who were referred because of symptoms consistent with
paraganglioma or follow-up after surgical removal of a
paraganglioma, neither routine imaging nor
octreotide scintigraphy revealed any abnormalities indicative of
paraganglioma. We conclude that: (1) virtually all
paragangliomas can be visualized using in vivo
111In-octreotide scintigraphy and (2) because conventional imaging is usually limited to the site where a
paraganglioma is clinically suspected,
octreotide scintigraphy, because of the information it provides on potential
tumor sites in the whole body, may be useful in detecting multicentricity or
metastases in patients with
paraganglioma.