ISSN:
1619-7089
Keywords:
Key words: Pituitary neoplasm
;
Thyrotropin
;
Octreotide
;
Hyperthyroidism
;
Single-photon emission tomography
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract. Few data are available on the visualization of somatostatin receptors in vivo in patients with thyrotropin (TSH)-secreting adenoma. We studied five patients with TSH-secreting adenomas using single-photon emission tomography (SPET) after administration of indium-111 pentetreotide. The intensity of 111In-pentetreotide uptake by the tumours was correlated with the degree of TSH suppression after a single administration of 100 μg octreotide s.c. Five patients (three women and two men) aged 27–46 years were investigated. Except for one patient with acromegaly, all had pure TSH-secreting tumours. One patient was previously untreated, while two had received octreotide, one antithyroid drugs, and one radioiodine. In all patients SPET demonstrated increased uptake of 111In-pentetreotide by the pituitary adenoma. The target to non-target ratio (T/nT) of 111In-pentetreotide uptake was higher than 10 in three patients. Administration of 100 μg octreotide s.c. caused a significant reduction in TSH levels from 4.8±1.4 mU/l to a nadir of 3.1±1.1 mU/l after 6 h (P〈0.001 by ANOVA). Suppression of TSH secretion ranged from 30% to 60% of the baseline value. The T/nT ratio showed a trend toward a direct relationship with the degree of TSH inhibition after acute octreotide administration (r=0.67; P=NS). Our study showed that 111In-pentetreotide scan visualized somatostatin receptors in all five of the patients with TSH-secreting pituitary adenomas, confirming the frequent presence of somatostatin receptors in these rare tumours, even though the correlation with the TSH inhibition after a single administration of octreotide did not reach significance.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00879659
Permalink
