Somatostatin Analog Treatment of Acromegaly Before Pituitary Surgery : Comparison With Neurosurgery Alone

Somatotroph pituitary adenoma is the most frequent cause of acromegaly. A transsphenoidal removal of the tumor is used as the first line treatment. Somatostatin analogs are used as to whether recovery was not obtained after surgery or pituitary surgery was contraindicated. Previous studies with somatostatin analogs have shown a drop in plasma GH and IGF-1 levels and a reduction in adenoma size in 75 and 25% of patients respectively. Retrospective studies suggest that a treatment with somatostatin analogs performed before surgery may be of interest to improve anesthesic conditions and surgical outcome. The aim of present study is to prospectively evaluate the interest of a first line treatment with a long-acting somatostatin analog (Sandostatin) before performing a pituitary surgery in acromegalic patients with either a micro or a macroadenoma to improve peri-operative conditions and hopefully surgical outcome. After informed consent, untreated acromegalic patients will be included and randomly assigned to one of the following treatment procedures : either pituitary surgery or a six month treatment with long-acting Sandostatin 30 mg monthly for 6 months before performing transsphenoïdal adenoma removal. The patients will be evaluated before any treatment, on months 3 and 6 of the treatment with Sandostatin (for the patients enrolled in this arm of the study) and on months 3 and 12 after pituitary neurosurgery. Each evaluation will include clinical data, hormone testing and radiological (MRI) investigation. The main endpoint will be the rate of recovery proved by a normalisation of GH secretion and plasma IGF-1 level. Secondary endpoints will include the evaluation of clinical, radiological, biological, anesthesic, surgical and pathological parameters. A comparison between the two arms will be performed at entry into the study, at the time of surgery and then on months 3 and 12 following the transsphenoidal removal of the somatotroph adenoma.

Inclusion criteria

• men and women
• 18-80 years old
• untreated acromegaly
• unsuppressed GH secretion after a glucose load and elevated IGF-1 plasma levels
• presence of a pituitary adenoma on MRI
• informed consent given.

Exclusion criteria

• acromegaly previously treated
• contraindication to pituitary surgery
• associated hyperprolactinemia above 200 ng/ml
• visual field defect needing rapid transsphenoidal surgery
• contraindication to a treatment with octreotide