Effect of octreotide LAR on the volume of pituitary adenoma in acromegalic patients
Anna Krzentowska, Agata Baldys-Waligorska & Filip Golkowski
We evaluated the volume of pituitary adenoma in patients treated with ocreotide LAR (SSLAR) prior to surgery.
Materials and methods: Twenty-six patients (22 females and 4 males, mean age 57.5±15.0 years) were treated with SSLAR: 5 patients with microadenoma during 6 months, and 21 patients with macroadenoma during 12 months before surgery, as recommended by the Polish Society of Endocrinology. Concentration of hGH and IGF1 was evaluated at 0, 3, 6 and 12 months, while MRI images were taken at 6 and 12 months prior to surgery. Volumes of pituitary adenomas, estimated as those of an ellipsoid, were based on MRI image projections. Basic statistics, ShapiroWilk and Wilcoxon tests were applied.
Results: Median values of hGH and IGF1 concentrations prior to treatment were 20 ng/ml (min 3.1; max 143.0) and 743.1 ng/ml (min 196.6; max 4744.4), respectively. After 6 and 12 months the median value of hGH concentration decreased to 10.3 ng/ml (min 2.1; max 68.3) and 3.0 ng/ml (min 1.2; max 17.7), respectively, while the median values of IGF1 became 570.0 ng/ml (min 137.6; max 1372.7) and 342.0 (min 154.8; max 1099.7), respectively. All differences were statistically significant (P<0.05). Prior to treatment the median values of the projected dimensions of pituitary adenomas along three orthogonal directions were: 15.5 mm (min 3.0; max 53.0), 12.0 mm (min 1.0; max 35.0) and 11.0 (min 1.0; max 32.0), while after 12 months of SSLAR administration, the respective median values were observed to decrease to: 9.0 mm (min 6.0; max 20.0), 8.5 mm (min 5.0; max 17.0), and 8.0 mm (min 5.0; max 14.0). The median volumes of adenomas were thus estimated at 1.1 ml (min 0.01; max 31.1) prior to treatment, 0.9 ml (min 0.1; max 11.7) after 6 months, and 0.37 ml (min 0.08; max 2.5) after 12 months of SSLAR administration.
Conclusions: Treatment of acromegalic patients with somatostatin analogues not only decreases hGH and IGF1 concentrations, but also appears to diminish the size of the tumour, in about 50% of patients treated, leading to general improvement of surgery conditions.