TY - JOUR
T1 - Indium-111 pentetreotide single-photon emission tomography in patients with TSH-secreting pituitary adenomas
T2 - Correlation with the effect of a single administration of octreotide on serum TSH levels
AU - Losa, M.
AU - Magnani, P.
AU - Mortini, P.
AU - Persani, L.
AU - Acerno, S.
AU - Giugni, E.
AU - Songini, C.
AU - Fazio, F.
AU - Beck-Peccoz, P.
AU - Giovanelli, M.
PY - 1997
Y1 - 1997
N2 - 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.
AB - 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.
KW - Hyperthyroidism
KW - Octreotide
KW - Pituitary neoplasm
KW - Single-photon emission tomography
KW - Thyrotropin
UR - http://www.scopus.com/inward/record.url?scp=8544277215&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=8544277215&partnerID=8YFLogxK
U2 - 10.1007/s002590050112
DO - 10.1007/s002590050112
M3 - Article
C2 - 9211757
AN - SCOPUS:8544277215
VL - 24
SP - 728
EP - 731
JO - European Journal of Pediatrics
JF - European Journal of Pediatrics
SN - 0340-6199
IS - 7
ER -