Magnetic Resonance Imaging: Prediction of surgical outcome

OBJECTIVES: The purpose of the study is to determine if pituitary Magnetic Resonance imaging (MRI) can predict the outcome of transsphenoidal surgery in patients with Cushing's disease. METHODS: Fifty four patients were divided in three groups according to MRI findings. those with a well circumscribed focal lesion clearly separated from the cavernous sinus (group 1, n = 24), those with adenomas in close contact with the cavernous sinus (group 2, n = 18), and those with no identified lesion (group 3, n = 12). RESULTS: The adenoma is found on the predicted side in 97,6% of the cases with positive MRI. A histologically proven adenoma is found in 96, 100 and 33% of the cases in groups 1, 2 and 3, with successful outcome in 91, 94 and 58% of the patients respectively, in group 2, surgery failed in a patient in whom tumoral tissue surrounded the internal carotid artery but succeeded in two other cases in whom a MRI involvement of the cavernous sinus was suspected. CONCLUSION: We confirm the excellent localization value of MRI. Failure due to cavernous sinus involvement can be predicted only when MRI shows that the adenomatous tissue surrounds the carotid artery. In cases of negative MRI, the outcome is less favorable.