Intraoperative Fluorescent Visualization of Pituitary Adenomas.

Tumor recurrence in pituitary adenomas is as high as 20% after surgery. Conventional neuronavigation and white light visualization are not sufficiently accurate in detecting residual neoplastic tissue. Fluorescence-guided surgery offers accurate, real-time visualization of neoplastic tissue. The authors' group has explored the use of near-infrared imaging, which is superior to visible-light fluorescence in both signal contrast and tissue penetration, in transsphenoidal endoscopic surgeries for pituitary adenomas using 2 techniques: second window indocyanine green, in which indocyanine green passively accumulates in the tumor, and OTL38, which actively targets folate receptors on adenoma cells. This work establishes the foundation of intraoperative near-infrared imaging for fluorescence-guided neurosurgery.