In vivo detection of somatostatin receptors in patients with functionless pituitary adenomas by means of a radioiodinated analog of somatostatin ((123I)SDZ 204-090)

Journal Article · Tue Oct 01 04:00:00 EDT 1991 · Journal of Clinical Endocrinology and Metabolism; (United States)

DOI:https://doi.org/10.1210/jcem-73-4-850· OSTI ID:5076618

Faglia, G; Bazzoni, N; Spada, A; Arosio, M; Ambrosi, B; Spinelli, F; Sara, R; Bonino, C; Lunghi, F ^[1]

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1. Institute of Endocrine Sciences, University of Milan, Ospedale Maggiore IRCCS (Italy)

The recent availability of a Tyr3-substituted octreotide (SDZ 204-090) for radioiodination has allowed somatostatin (SRIH) receptor binding to be studied in vivo, and receptor-positive tumors of different origins to be visualized with a gamma-camera. This prompted us to investigate whether this compound could be used for external imaging of functionless pituitary adenomas displaying SRIH receptors. Eight patients with functionless pituitary adenomas, three patients with acromegaly, and three with macroprolactinoma were injected iv with 123I-labeled Tyr3-octreotide and then scanned with a gamma-camera. Positive scans were obtained in the three acromegalics and in two of the eight patients with functionless pituitary tumors. The patients with macroprolactinoma had negative scans. The diagnosis of functionless pituitary adenomas was confirmed by light and electron microscopic examination as well as immunocytochemical studies. In vitro binding of (125I)Tyr11-SRIH to cell membranes was evaluated in four functionless and three GH-secreting adenomas removed from seven of the patients. All of the GH-secreting as well as one of the four functionless adenomas had high affinity SRIH-binding sites, without differences in number or affinity, whereas SRIH-binding sites were not detected in the others. Positive scans were observed only in patients bearing tumors with high affinity SRIH-binding sites. In conclusion, (123I)Tyr3-octreotide appears to be a promising tool for singling out, in vivo, patients with functionless pituitary tumors displaying SRIH receptors who might potentially benefit from octreotide treatment.

• OSTI ID: 5076618
• Journal Information: Journal of Clinical Endocrinology and Metabolism; (United States), Journal Name: Journal of Clinical Endocrinology and Metabolism; (United States) Vol. 73:4; ISSN JCEMA; ISSN 0021-972X
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ADENOMAS
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
CAMERAS
CELL CONSTITUENTS
CELL MEMBRANES
COUNTING TECHNIQUES
DIAGNOSIS
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
ENDOCRINE GLANDS
GAMMA CAMERAS
GLANDS
HOURS LIVING RADIOISOTOPES
IN VIVO
INTERMEDIATE MASS NUCLEI
IODINE 123
IODINE ISOTOPES
ISOTOPES
KINETICS
MEMBRANE PROTEINS
MEMBRANES
NEOPLASMS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PATIENTS
PITUITARY GLAND
PROTEINS
RADIOISOTOPE SCANNING
RADIOISOTOPES
REACTION KINETICS
RECEPTORS
SOMATOSTATIN