A Case Report of Bilateral Adrenal Gland Stereotactic Body Radiotherapy to Manage Hypercortisolemia in a Patient With Ectopic Adrenocorticotropic Hormone (ACTH) Production From a Metastatic Pancreatic Neuroendocrine Tumor

A 63-year-old woman presented with hypokalemia, hypertension, weight gain, limb edema, and tremors. She was diagnosed with Cushing syndrome, with a 24-hour urine cortisol level of 41,013 nmol/day. Investigations revealed a grade 2 pancreatic neuroendocrine tumor with extensive hepatic metastases. Owing to excessive adrenocorticotropic hormone production from her disease, her hypercortisolemia and Cushing symptoms worsened despite ketoconazole, somatostatin analogs, and right liver lobe chemoembolization. Stereotactic body radiotherapy (SBRT) at a dose of 39 Gy in three fractions was administered to her bilateral adrenal glands in the hope of reducing her cortisol levels and improving her symptoms. Her 24-hour urine cortisol levels decreased following SBRT, but not rapidly enough; her clinical condition continued to deteriorate, and she died 21 days after treatment. SBRT was not effective as an urgent intervention in this setting; a greater latency to realize a response is likely necessary.