Endocrine Abstracts

In some patients with Cushing’s disease (CD), magnetic resonance imaging (MRI) fails to detect small pituitary ACTH-secreting adenomas despite the results of endocrine evaluation indicating Cushing’s disease.

Aim: The aim of this paper is to study frequency of hypocorticism after radiosurgery – protonotherapy (PT) for patients with normal MRI for Cushing’s disease and for patients with confirmed adenomas.

Methods: Between 1997 and 2002, 125 patients with CD underwent PT at our institution: 59 patients with normal MRI (group 1) and 66 patients with confirmed adenomas (group 2). Their results were analyzed retrospectively.

Results: Clinical improve occurred in 88.6% pat. of group 1 and in 95.9% pat. of group 2; complete hormonal remission was achieved in 81.1% patients with normal MRI and in 70% pat. with confirmed adenomas. Recurrence after PT was documented only in two patients of group 2. Radiologically-induced hypocorticism have occurred in 20.3% (12/59) pat. of group 1 and in 12.3% (8/66) pat. of group 2 (P=0.33). These data is comparable with results of selective adenomectomy.

Conclusion: PT can be performed for Cushing’s disease with normal MRI. Patients with no histological confirmation of tumor after PT for CD are likely to have a good outcome. The results do not differ significantly from reported hypocorticism rates in patients with confirmed adenomas.