SAT627 Is Cyberknife Stereotactic Radiosurgery Effective For Treating Cushing’s Disease?

Abstract

Abstract Disclosure: G. Wintermyer: None. E. Villanueva: None. Patients with pituitary adenoma can often present with endocrine abnormalities. Transsphenoidal surgery(TSS) is the “gold standard” treatment. In patients with recurrent or post-surgery remaining adenoma, stereotactic radiosurgery with CyberKnife (CKRS) has demonstrated to be a good adjuvant therapy. Occasionally patients develop hypopituitarism and adrenal insufficiency (AI) post CKRS. Here is a patient with ACTH-secreting pituitary adenoma with Cushing’s disease who developed remission afterCKRS:52-year-old-male with PMHx of T2DM, hypothyroidism, HTN presented to hospital complaining of fatigue, ataxia, 40-lbs weight loss over four months and mood changes. Due to ataxia, CT of the head was done which revealed an Empty Sella. During the workup, ACTH and cortisol were detected 131 pg/mL and 37.5 ug/dL respectively. After ruling out life-threatening medical conditions, he was discharged with endocrinology referral for Empty Sella syndrome (ESS) and elevated ACTH. During endocrinology evaluation, patient was sent for testosterone, LH, FSH, ACTH, AM cortisol, prolactin and DHEAS tests. Results were as follows: elevated ACTH (91 pg/mL) and Cortisol (33.5ug/dL), elevated DHEAS (401 ug/dL) and prolactin (15 NG/dL), low testosterone (72 NG/dL), within appropriately low LH and FSH. Later, PM Salivary cortisol level, Dexamethasone suppression test(DST), and urine free cortisol (UFC) level were tested. He had pituitary MRI concurrently. Salivary cortisol and UFC were high. There was no suppression of cortisol level after DST. Pituitary MRI demonstrated pituitary tumor. He was diagnosed with Cushing’s disease and was referred to neurosurgery for pituitary tumor TSS. Patient was started on Ketoconazole prior to surgery. Pathology confirmed ACTH-secreting pituitary adenoma. After surgery, Cortisol level normalized, and the patient regained his energy. Post-surgery MRI showed complete resection of adenoma. Ketoconazole was discontinued post-operatively. Two years later, during routine workup, there were elevations in 24-hour and PM salivary cortisol levels. The patient was asymptomatic. He failed his DST. Repeat pituitary MRI showed small hypo enhancement at the bottom of Sella suspicious for pituitary adenoma recurrence. The patient underwent CKRS. Cortisol level and pituitary axis activity remained normal since CKRS. No change was noted in the six-month and one-year surveillance MRI. Even though TSS is a “gold standard” treatment for pituitary adenoma, the likelihood of remaining residues or recurrence of the tumor is high. Frequent pituitary hormone checks can detect recurrence of adenoma before emerging symptoms. CKRS should be considered as a therapeutic option for recurrent adenoma. Clinicians should frequently check patients for hypopituitarism and AI post-CKRS. Clinicians should also recognize that ESS may contribute to MRI-negative Cushing’s disease. Presentation: Saturday, June 17, 2023