Page 72 - Fluorescence-guided cancer surgery
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Chapter 5
ABSTRACT
Background: The intraoperative distinction between normal and abnormal pituitary tissue is crucial during pituitary adenoma surgery to obtain a complete tumor resection, while preserving endocrine function. Near-Infrared (NIR) uorescence imaging is a technique to intraoperatively visualize tumors by using Indocyanine Green (ICG); a contrast agent allowing visualization of di erences in tissue vascularization. Although NIR uorescence imaging has been described in pituitary surgery it has, in contrast to other surgical areas, never become widely used.
Objective: To evaluate NIR uorescence imaging in pituitary surgery both qualitatively and quantitatively, and to assess the additional value to resect adenoma tissue under NIR uorescence guidance.
Methods: We included ten patients planned for transnasal transsphenoidal selective adenomectomy. Patients received multiple intravenous administrations of 5 mg ICG, up to a maximum of 15 mg per patient. Endoscopic NIR uorescence imaging was performed at multiple points in time. The NIR uorescent signal in both the adenoma and pituitary gland was obtained and the Fluorescence Contrast Ratio (FCR) was assessed.
Results: Four patients had Cushing’s disease, one had Acromegaly and one had a Prolactinoma. Four patients had a non-functioning macro-adenoma. In nine out of 10 patients with a histologically proven pituitary adenoma, the normal pituitary gland showed stronger uorescent signal than the adenoma. A FCR of normal pituitary gland to adenoma of 1.5 ± 0.2 was obtained. In two patients, adenoma resection actually took place under NIR uorescence guidance, instead of under white light.
Conclusion: NIR uorescence imaging can easily and safely be implemented in pituitary surgery. Timing of ICG administration is important for optimal results and warrants further study. It appears that injection of ICG can best be postponed until some part of the normal pituitary gland is identi ed. Subsequent repeated low-doses ICG administration improved the distinction between adenoma and gland.
