In vivo somatostatin receptor imaging in medullary thyroid carcinoma.

Abstract

Using in vivo scintigraphy with the 111In-labeled somatostatin analog octreotide, tumor localizations were demonstrated in 11 of 17 patients (65%) with medullary thyroid carcinoma (MTC). Tumor localizations in the liver in 7 patients, and in the thyroid in 1 patient were not detected on octreotide scintigraphy, most probably because of normal uptake of labeled octreotide in these organs. Specific somatostatin receptors were demonstrated in vitro on all 5 investigated tumors which had also been visualized in vivo, as well as on 1 tumor that was not. Immunohistochemically, somatostatin was present in 1 of 6 tumors that were visualized in vivo, and in neither of 2 tumors that were not. The ratio of serum calcitonin over carcino-embryonic antigen concentrations was significantly higher in patients whose MTCs were visualized during octreotide scintigraphy than in those whose tumors were not. We have formed the following conclusions: 1) In the majority of patients with metastatic MTC, tumor sites can be visualized using octreotide scintigraphy, although this technique is insensitive in detecting liver metastases or intrathyroidal tumor; 2) The visualization of MTC during in vivo somatostatin receptor imaging correlates with the in vitro presence of somatostatin receptors; 3) The immunohistochemical presence of somatostatin in the tumor does not seem to influence the outcome of in vivo somatostatin receptor imaging; and 4) Higher serum calcitonin over carcino-embryonic antigen ratios in patients whose MTC is visualized during octreotide scintigraphy might imply that somatostatin receptors are present on more differentiated MTC.

• Authors: D J Kwekkeboom, J C Reubi, S W Lamberts, H A Bruining, A H Mulder, H Y Oei, E P Krenning
• Journal: The Journal of clinical endocrinology and metabolism (J Clin Endocrinol Metab) Vol. 76 Issue 6 Pg. 1413-7 (Jun 1993) ISSN: 0021-972X [Print] United States
• PMID: 8501144 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Carcinoembryonic Antigen
• Receptors, Somatostatin
• Calcitonin
• Octreotide

Topics

• Adult
• Aged
• Aged, 80 and over
• Autoradiography
• Calcitonin (blood)
• Carcinoembryonic Antigen (blood)
• Carcinoma (blood, diagnostic imaging, metabolism)
• Female
• Humans
• Male
• Middle Aged
• Octreotide
• Radionuclide Imaging
• Receptors, Somatostatin (metabolism)
• Thyroid Neoplasms (blood, diagnostic imaging, metabolism)