Folate receptor overexpression can be visualized in real time during pituitary adenoma endoscopic transsphenoidal surgery with near-infrared imaging

OBJECTIVEPituitary adenomas account for approximately 10% of intracranial tumors and have an estimated prevalence of 15%–20% in the general US population. Resection is the primary treatment for pituitary adenomas, and the transsphenoidal approach remains the most common. The greatest challenge with pituitary adenomas is that 20% of patients develop tumor recurrence. Current approaches to reduce recurrence, such as intraoperative MRI, are costly, associated with high false-positive rates, and not recommended. Pituitary adenomas are known to overexpress folate receptor alpha (FRα), and it was hypothesized that OTL38, a folate analog conjugated to a near-infrared (NIR) fluorescent dye, could provide real-time intraoperative visual contrast of the tumor versus the surrounding nonneoplastic tissues. The preliminary results of this novel clinical trial are presented.METHODSNineteen adult patients who presented with pituitary adenoma were enrolled. Patients were infused with OTL38 2–4 hours prior to surgery. A 4...