Endocrine Abstracts

Purpose: Transsphenoidal endoscopic surgery (TSS) is the first-line treatment for Cushing’s disease (CD). However, persistence and recurrence of hypercortisolism after TSS considered important problem. In this case search for CD remission predictors is actual.

Aim: To study the role of preoperative oral high-dose dexamethasone suppression test (HDDST) and pituitary MRI in the prognosis of CD remission after TSS.

Materials and methods: Fifty-nine patients with Cushing’s disease (9 men, 50 women, mean age 40 years (15–72) underwent TSS were included. Before the TSS HDDST and pituitary MRI were performed in all cases. Postoperative examination was done one year after surgery. Remission criteria were: secondary adrenal insufficiency (the need for glucocorticoid replacement) or combination of normal midnight ACTH and serum cortisol levels, normal 24 hour urine free cortisol (UFC) excretion and serum cortisol suppression less than 50 nmol/l in 1-mg dexamethasone test. The optimal threshold value of serum cortisol suppression in the HDDST for prediction of CD remission after TSS was calculated by ROC-analysis.

Results: One year after surgery CD remission was confirmed in 39 patients, whereas in 20 patients hypercortisolism persisted. The optimal threshold value of serum cortisol suppression in the HDDST for prediction of CD remission after TSS was 72%. Test’s sensitivity and specificity were 82% and 84%, respectively. The probability of wrong prediction was 17% (P=0.0001). In our study, the results of TSS did not correlate with MRI adenoma size.

Conclusion: According to our data serum cortisol suppression more than 72% in HDDST may be used as a prognostic criterion for CD remission after TSS.