Gamma Knife Radiosurgery as a Successful Adjunctive Therapy in Cushing's Disease: Case Report

Pituitary adenomas are categorized into two groups: the secretory and non-secretory adenomas. The first group overproduce normal pituitary hormones, which cause Cushing’s disease (high ACTH- adernocorotitrophic hormone), Acromegaly (high growth hormon) and prolactinomas (high prolactin). They may diffuse into the sphenoid sinus, cavernous sinus and diaphragma sellae. Tumor invasion into the adjacent structures and incomplete tumor resection are the most common causes of hypercortisolism after the first surgery. The first explored radiation modality for persistent Cushing’s disease was fractionated radiation, with increased rates of hypopituitarism. Over time, several studies have demonstrated the power of the GKS (gamma knife surgery) for persistent Cushing’s disease.
A 32-year-old female who was diagnosed with Cushing’s disease secondary to an ACTH secreting pituitary adenoma, underwent trans-sphenoidal resection of the adenoma. Surprisingly, no postoperative hormonal and clinical improvements were observed. The patient was treated with oral ketoconazole. Twenty months after surgery, she had complaints of sudden onset of headache with diplopia, ptosis and paralysis of extraocular muscles of the left eye. A repeated MRI revealed residual tumor with local invasion to the left cavernous sinus. Following the consultation with a neurosurgeon, the patient underwent GKS. Within two months, there was a significant improvement in peribulbar muscle paresis and laboratory results were satisfying.
The case presented here indicates that the most common indicators for radiosurgery are residual tumors, especially in the cavernous sinus, which are recurrent and/or resistant to medical treatment. The purpose is to call attention to the GKS as a successful adjunctive therapy in Cushing’s disease.