Indium-111 pentetreotide single-photon emission tomography in patients with TSH-secreting pituitary adenomas: correlation with the effect of a single administration of octreotide on serum TSH levels

Losa, M.; Magnani, P.; Mortini, P.; Persani, Luca; Acerno, S.; Giugni, E.; Songini, C.; Fazio, F.; Beck‐Peccoz, Paolo; Giovanelli, M.

doi:10.1007/s002590050112

Cited by 6 publications

(6 citation statements)

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“…According to our results, and as observed with carcinoid tumors (28) or thyreotroph adenomas (29), a positive response to the short octreotide test appears to be predictive of the efficacy of octreotide treatment in our patients with benign insulinomas. Unlike what had been reported previously (6, 30), we did not observe worsening of hypoglycemia in patients treated with octreotide.…”

Section: Discussionmentioning

confidence: 70%

Octreotide in insulinoma patients: efficacy on hypoglycemia, relationships with Octreoscan scintigraphy and immunostaining with anti-sst2A and anti-sst5 antibodies

Vezzosi¹,

Bennet²,

Rochaix³

et al. 2005

eur j endocrinol

164

119

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Objective: We studied the efficacy of octreotide treatment on hypoglycaemia in patients with insulinoma and its relationships with Octreoscan scintigraphy and the presence of tumoral somatostatin receptors sst2A and sst5. Design and methods: 17 patients with insulinoma were evaluated using (i) evaluation of blood glucose, insulin and C-peptide during a short 100 mg octreotide test in fasting patients and/or treatment over 8 days-8 months with octreotide, (ii) Octreoscan scintigraphy and (iii) immunostaining of the tumor with anti-sst2A and anti-sst5. Results: Octreotide was effective on hypoglycaemia in 10/17 patients. Octreoscan scintigraphy detected 4/17 insulinomas. sst2A receptor was detected in 7/17 insulinomas and sst5 in 15/17 insulinomas. Octreotide was effective on hypoglycaemia in those seven patients with sst2A receptorexpressing insulinoma, and in three patients with undetectable sst2A receptor and detectable sst5; it was ineffective in six patients whose tumor expressed the sst5 receptor with undetectable sst2A and in one patient with undetectable sst2A and sst5 receptor. Conclusions: Octreotide is an effective treatment of hypoglycaemia in more than 50% of patients with insulinoma. Detection of responsive patients was better based on a positive short test with subcutaneous octreotide than on the results of Octreoscan scintigraphy. Positive anti-sst2 receptor immunostaining is associated with efficacy of octreotide treatment, but does not account for all cases of responsiveness to octreotide. Expression of sst5 receptor does not appear to explain per se the efficacy of octreotide on sst2A-negative insulinomas.European Journal of Endocrinology 152 757-767

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Section: Discussionmentioning

confidence: 70%

Octreotide in insulinoma patients: efficacy on hypoglycemia, relationships with Octreoscan scintigraphy and immunostaining with anti-sst2A and anti-sst5 antibodies

Vezzosi¹,

Bennet²,

Rochaix³

et al. 2005

eur j endocrinol

164

119

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“…Previous reports that TSHomas expressed somatostatin receptors support OCT therapy for TSHdependent hyperthyroidism [8,[17][18][19][20][21]. According to these reports, OCT suppressed TSH levels in more than 90% of patients with TSHomas and it also decreased serum thyroid hormone levels to normal ranges in 70% of the patients.…”

Section: Discussionmentioning

confidence: 85%

Expression of Type 5 Somatostatin Receptor in TSH-secreting Pituitary Adenomas: A Possible Marker for Predicting Long-term Response to Octreotide Therapy

et al. 2007

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Abstract. In TSH-secreting pituitary adenomas (TSHoma), octreotide (OCT) therapy reduces tumor size and TSH secretion in some cases but not in others. As OCT acts through various types of somatostatin receptors (SSTRs), the different responses of TSHoma to OCT might be explained by the differences of SSTR expression. We therefore studied the expression of subtype-specific SSTR mRNA transcripts in tumor tissues by RT-PCR. Type 2 (SSTR2) mRNA transcripts were detected in all 8 tumors but those of SSTR3 and SSTR5 were demonstrated only in 5 of them. Serum TSH levels were decreased by OCT administration test in all patients but OCT therapy was effective in two patients out of three. SSTR5 mRNA was detected in two tumors from the responder, but not in one tumor that was resistant to OCT. These observations suggest that the temporal decrease of TSH by OCT may be mediated by SSTR2, and that the long term response to OCT therapy may be related with the expression of SSTR5. Therefore, the expression of SSTR5 in TSHoma may be a useful marker for predicting the outcome of the therapy, but further studies with larger numbers of patients are necessary.

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“…In contrast, since TSH-secreting adenomas express somatostatin receptors [90], biochemical disease can be controlled with octreotide therapy in most patients; TSH levels have been reported to normalise in 79% of patients and tumour shrinkage can occur in 50% of cases [87, 88, 89, 90, 91, 92, 93]. Octreotide treatment is also considered useful preoperatively as it facilitates tumour removal [87].…”

Section: Tsh-secreting Pituitary Adenomasmentioning

confidence: 99%

New Medical Approaches in Pituitary Adenomas

et al. 2000

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Recently, the medical approach to patients with secreting and clinically non-functioning pituitary adenomas has received great impulse thanks to the availability of new, selective and long-lasting compounds with dopaminergic activity, such as cabergoline, and of somatostatin analogues provided in slow-release formulations, such as lanreotide and octreotide long acting release (LAR). In particular, the use of cabergoline has induced control of hyperprolactinaemia and tumour shrinkage in the great majority of patients with micro- and macroprolactinomas. Cabergoline treatment restores fertility both in women and men, and partially improves osteoporosis, one of the major complications of hyperprolactinaemia. In acromegaly, disease control (growth hormone [GH] <2.5–1.0 μg/l as a fasting or glucose-suppressed value, respectively, together with age-normalised insulin-like growth factor [IGF]-I) is achievable in more than half of patients receiving treatment with lanreotide or octreotide-LAR. Improvement in cardiomyopathy, sleep apnoea and arthropathy has been reported during GH/IGF-I suppression after pharmacotherapy. A synthetic GH analogue, B2036-PEG, that antagonises endogenous GH binding to its receptor-binding sites and a GH-releasing hormone antagonist that blocks the effect of this releasing factor on the hypothalamus and pituitary are presently under investigation in acromegaly. Preliminary studies have clearly demonstrated the effectiveness of the GH receptor antagonist in suppressing IGF-I levels in acromegalic patients previously unresponsive to somatostatin analogues. Beneficial effects of subcutaneous octreotide and lanreotide have also been reported in adenomas secreting thyroid-stimulating hormone, while the results of treatment with dopamine agonists or somatostatin analogues remain disappointing in patients with clinically non-functioning adenomas. In these patients the possibility of visualising in vivo the expression of D₂ receptors using specific radiotracers such as ¹²³I-methoxybenzamide has allowed selection of patients likely to respond to cabergoline. Scant effects of pharmacotherapy have also been reported in patients with adenomas secreting adrenocorticotropic hormone. However, some preliminary data suggest a potential use of cabergoline in combination with ketoconazole, or alone, in selected cases of Cushing’s disease or Nelson’s syndrome.

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Indium-111 pentetreotide single-photon emission tomography in patients with TSH-secreting pituitary adenomas: correlation with the effect of a single administration of octreotide on serum TSH levels

Cited by 6 publications

References 0 publications

Octreotide in insulinoma patients: efficacy on hypoglycemia, relationships with Octreoscan scintigraphy and immunostaining with anti-sst2A and anti-sst5 antibodies

Octreotide in insulinoma patients: efficacy on hypoglycemia, relationships with Octreoscan scintigraphy and immunostaining with anti-sst2A and anti-sst5 antibodies

Expression of Type 5 Somatostatin Receptor in TSH-secreting Pituitary Adenomas: A Possible Marker for Predicting Long-term Response to Octreotide Therapy

New Medical Approaches in Pituitary Adenomas

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