[111In-DTPA-D-Phe]-octreotide scintigraphy in functioning and non-functioning pituitary adenomas.
Scintigraphy with [111In-DTPA-D-Phe]-octreotide is a recently developed technique for imaging somatostatin receptors in many neuroendocrine tumors. A good correlation between high [111In-DTPA-D-Phe]-octreotide uptake and the response to octreotide therapy has been proved in TSH- and GH-secreting pituitary adenomas, while few and conflicting scintigraphic data on somatostatin receptors in non-functioning tumors have been reported in the literature. The present study presents the results obtained with [111In-DTPA-D-Phe]-octreotide scintigraphy in thirteen patients with GH-secreting pituitary adenoma, four patients with inappropriate TSH-secretion and twelve patients with non-functioning pituitary adenoma. Twelve out of the 13 patients with GH-secreting pituitary adenomas had a positive scan; moreover, in 5/6 patients with a GH-secreting microadenoma (tumor size range 5-8 mm) a positive scan was found. Two TSH-secreting macroadenomas had a positive scan while a negative scan was obtained for a TSH-secreting pituitary microadenoma and in a patient with non-neoplastic, inappropriate secretion of TSH. Finally, only 2/12 patients with non-functioning pituitary adenoma showed a positive scan. In conclusion, [111In-DTPA-D-Phe]-octreotide scintigraphy is a useful tool to confirm the presence of somatostatin receptors in selected patients with GH- and TSH-secreting pituitary adenoma. The role of [111In-DTPA-D-Phe]-octreotide scintigraphy in non-functioning pituitary tumors remains to be established, but it could be useful for octreotide treatment in patients who refuse surgery or who are poor surgical candidates.
Boni
G
G
Division of Nuclear Medicine, University of Pisa, Italy.
Ferdeghini
M
M
Bellina
C R
CR
Matteucci
F
F
Castro Lopez
E
E
Parenti
G
G
Canapicchi
R
R
Bianchi
R
R
D000236:Adenoma / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D005260:Female; D019382:Human Growth Hormone / Q000378:metabolism; D006801:Humans; D007205:Indium Radioisotopes / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D017599:Neuroectodermal Tumors / Q000000981:diagnostic imaging; D015282:Octreotide / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000627:therapeutic use; D004369:Pentetic Acid / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D010911:Pituitary Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism / Q000601:surgery; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D017481:Receptors, Somatostatin / Q000378:metabolism; D012886:Skull / Q000378:metabolism; D013972:Thyrotropin / Q000378:metabolism; D015899:Tomography, Emission-Computed, Single-Photon
D018931:Antineoplastic Agents, Hormonal; D007205:Indium Radioisotopes; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin; D019382:Human Growth Hormone; C071632:SDZ 215-811; D004369:Pentetic Acid; D013972:Thyrotropin; D015282:Octreotide