MON-LB59 Radiofrequency Ablation as a Primary Therapy for Benign Functioning Insulinoma

Background Insulinomas are rare life-threatening pancreatic neuroendocrine tumors. Surgical removal continues to be the treatment of choice for such benign cases with a high cure rate. However, surgery is associated with a considerable risk of morbidity and mortality.Here we describe a case of benign solitary insulinoma successfully treated with RFA in a patient who strongly refused surgery. Case Description A 56-year- old non- diabetic, male is known to have hypertension and lymphoma diagnosed at age of 20 years, in remission. He presented with recurrent episodes of transient ischemic attack and stroke over the last three years. A change in his cognitive function, behavior, and memory was noticed. During his hospital stay for the second episode of stroke, he was found to have hypoglycemia which was asymptomatic. Insulinoma was confirmed based on the followings: low plasma glucose level of 2.04 mmol/l (4.0- 5.6), inappropriately elevated plasma f insulin and C-peptide 68.9 mU/l (3-13) and 4.08 ug/l (1.0-3.1); respectively. Sulfonylurea screening test was negative. MRI of the abdomen showed a 3.2x2.5 cm, well-circumscribed hypervascular lesion at the uncinate process of the pancreas, which is compatible with neuroendocrine tumor. Treatment modalities have been explained to the patient who was fully informed about the risk and benefit of each treatment option. However, he strongly refused surgery. Meanwhile, he was admitted with a third attack of stroke with concurrent hypoglycemia. In view of his refusal of the surgical treatment and due to his recent stroke and high-risk status for surgery, the option of radiofrequency ablation was decided. RFA of the pancreatic tumor using 40.75 GY fractions was carried out with a favorable outcome. The patient achieved biochemical normalization and remains euglycemic during his follow up. Reversal of his cognitive, behavioral, and memory changes was recognized. CT abdomen during a follow-up of 2 months after radiation showed a mild regression of the size of the tumor with no evidence of new lesions or distance metastasis. He remained under close follow up at the neuroendocrine clinic. ConclusionThis case shows a treatment challenge which required the use of an alternative treatment option other than the standard of care in managing a case of benign insulinoma. Successful treatment was achieved in our case with the use of RFA rather than surgery. This report highlights the evolving evidence of nonsurgical RFA being a potential safe, feasible therapeutic modality option or even an alternative to surgery in selected cases of benign insulinoma. Because of the rarity of this tumor and low rate of therapeutic application of RFA in similar cases, the role of RFA had not been extensively studied. Large studies are needed to evaluate the long-term outcomes of RFA in this setting.