Stereotactic Radiosurgery for Cushing Disease

Cheng-Chia LeeTaiwan Speaker Stereotactic Radiosurgery for Cushing DiseaseCushing disease, caused by adrenocorticotropic hormone (ACTH)–secreting pituitary adenomas, remains a therapeutic challenge due to tumor invasiveness, difficulty in achieving complete resection, and the risk of recurrence following surgery. While transsphenoidal surgery is considered first-line treatment, a substantial proportion of patients experience persistent or recurrent hypercortisolism, necessitating adjuvant therapies. Stereotactic radiosurgery (SRS) has emerged as an effective and minimally invasive treatment modality for residual or recurrent Cushing disease, offering precise, high-dose radiation delivery to the target lesion while sparing surrounding critical structures. Clinical evidence demonstrates that SRS achieves long-term biochemical remission in a significant proportion of patients, with reported cortisol normalization rates increasing over time after treatment. Tumor control rates are consistently high, exceeding 90% in most series. Although the therapeutic effect of SRS is delayed compared to surgery, it provides durable disease control with an acceptable safety profile. Hypopituitarism remains the most common adverse effect, whereas cranial neuropathy and optic pathway injury are rare when strict dose constraints are observed. Advances in imaging, target delineation, and dose planning have further enhanced the efficacy and safety of SRS. Overall, stereotactic radiosurgery represents a critical component of multimodal management for Cushing disease, particularly in patients with surgically refractory disease, recurrent tumors, or contraindications to repeat surgery. Long-term endocrine follow-up remains essential to monitor treatment response and late radiation-related effects.