Introduction: Patients with persistent or recurrent Cushing’s disease (CD) after prior transsphenoidal surgery (TSS) require further treatment to reduce the metabolic consequences of their condition. We assess outcomes of patients having stereotactic radiosurgery (SRS) for corticotropin (ACTH) secreting pituitary adenomas and propose a radiosurgical management algorithm.
Methods: Retrospective review of 38 patients without prior radiation treatment having SRS for ACTH-secreting pituitary adenomas from 1990 to 2015 (Figure 1). A favorable outcome was defined as normalization of 24-hour urinary free cortisol and tumor growth control in patients with CD, and tumor growth control in patients with ACTH-secreting tumors who underwent bilateral adrenalectomy (Adx). The median follow-up after SRS was 71 months (range, 9-291).
Results: A favorable outcome was achieved by 13 of 18 patients with CD (72%) at a median of 14 months (range, 5-47). Five patients with CD required additional treatment (Adx, n=3; repeat TSS, n=1; repeat SRS, n=1) at a median of 53 months (range, 9-99). Eighteen of 20 patients (90%) having Adx had a favorable outcome. Two patients (10%) had tumor growth requiring additional treatment (repeat TSS + repeat SRS, n=1; repeat SRS, n=1). Favorable outcomes were more frequent in the Adx group compared to the CD group at 1-year (100% vs. 33%, P<0.001) and 3-years (100% vs. 62%, P<0.01), but no different at 5-years (88% vs. 77%, P=0.63) (Figure 2).
Conclusions: The majority of patients with ACTH-secreting pituitary adenomas benefit from SRS. We propose a treatment algorithm in which patients with mild to moderate CD should be considered for SRS, whereas patients with severe CD are better candidates for Adx with either concurrent SRS or SRS performed at a later date if tumor growth is detected (Figure 3).
Patient Care: By showing that both bilateral adrenalectomy and stereotactic radiosurgery are effective for Cushing's disease that persists or reoccurs after transsphenoidal surgery.
Learning Objectives: Understand the treatment strategies of stereotactic radiosurgery and bilateral adrenalectomy for persistent or recurrent Cushing's disease after prior transsphenoidal surgery