EFFECTS OF SANDOSTATIN ON THE SIZE OF GH-SECRETING PITUITARY TUMORS
Knoepfekmacher M, Apfelbaum P, Salgado LR, Pimentel F, Cukiert A, Liberman B.
Serviço de Endocrinologia, Hospital Clínicas, FMUSP, São Paulo-SP.
Sandostatin (an analogous of somatostatin) is a potent inhibitor of GH secretion. It is able to decrease GH levels in 80% of the patients with GH-secreting tumors and cause a decrease in size in 20-40% of these tumors.
We report on the effects of high-dose sandostatin treatment in 2 patients who showed a significant decrease in their tumor size.
- Case I: a 30 years-old female has been previously operated and left with significant intracavernous and supra-sellar residual tumor, including chiasmatic compression. She refused radiotherapy and was started on sandostatin, initially with 500 m g / day and progressive increase through 1000 m g / day. GH after sandostatin treatment was still high (30 ng/ml) but there was a marked decrease in tumor size as seen on MRI. Tumor size increase was documented after 1 month of drug withdrawal and a new decrease in size was achieved after restarting sandostatin;
- Case II: A 50 years old female with acromegalic phenotype and hypertension, diabetes and previous cardiopathy and CNS stroke was considered a poor candidate for surgery and was started on sandostatin 500 mg / day with dose increment untill 1500 mg / day. Her pre-treatment MRI showed a macroadenoma with invasion of the esphenoidal sinus. Four months after treatment, MRI showed a 50% reduction in tumor size and GH levels normalization. Even not being the rule, sandostatin can achieved marked size reduction in GH-secreting pituitary tumors.