Does octreotide treatment improve the surgical results of macro-adenomas in acromegaly? A randomized study

It is not clear whether the pre-operative treatment of GH-secreting pituitary adenomas with Octreotide improves the surgical remission rates of acromegaly. In a prospective controlled study the results of transsphenoidal surgery in newly diagnosed GH-secreting macro-adenomas were compared in patients with (n = 11, group A) and without (n = 13, group B) preoperative Octreotide treatment. During the treatment with a daily dosage of 470 +/- 160 micrograms Octreotide for 16.5 +/- 10 weeks, the GH- and IGF-1-values of group A dropped significantly from 38.9 +/- 34.1 to 6.8 +/- 4.9 micrograms/l and from 2.7 +/- 1 to 1.7 +/- 0.7 arbitrary units respectively. The adenoma-shrinkage from 5.9 +/- 5.8 to 4.7 +/- 4.9 cm3 missed statistical significance by little. There was no statistically significant difference between the postoperative acromegaly remission rates of 55% in group A and 69% in group B. Of the adenomas that postoperatively were not in remission, 80% in group A and 75% in group B disclosed an infiltrative growth pattern not influenced by the Octreotide pretreatment. All other patients not cured presented with initial GH-values of > 50 micrograms/l. There was no statistically significant difference between the postoperative anterior pituitary function in the two patient groups. In this study Octreotide was not beneficial in improving the results of GH-secreting pituitary macro-adenoma surgery. However, larger prospective controlled studies are needed to address this issue.