The research design is a prospective clinical study. All patients enrolled in the study will
prepare for surgery as per standard neurosurgical indications, procedures and institution
protocols. At the time of the anesthesia induction, with the patient under general
anesthesia, Fluorescein Sodium 10% (100mg/1mL) at a dose of 500mg (100mg/ml) will be
administered intravenously (the optimal dosage will be determined within the study as the
most minimal dose for adequate visualization will be used). Surgery will continue with the
aid of the Yellow 560 microscope with a minimum delay of 10 minutes after injection to reduce
the amount of leakage of Fluorescein Sodium into the surrounding tissue.
Conventional microsurgical and biopsy procedures and techniques including histopathology and
intraoperative imaging will be performed through the completion of the surgery. The surgeon
will resect and remove what he believes is the tumor based on previously known criteria
(standards of care) regardless of what the Fluorescein angiography demonstrates. For vascular
lesions, fluorescein sodium 10% (100mg/1mL) will be injected and used to assess its
application after the conventional methods have confirmed the exclusion of the aneurysm. No
patient's care will be affected by the results of the Fluorescein angiography.
No other additional neurosurgical instruments will be used. Patients will be treated
post-operatively with conventional adjunctive therapies and imaging as deemed necessary by
the attending neurosurgeon for the evaluation of extent of surgery. Follow-up data (including
post-operative images assessing outcomes and complications) will be collected on all patients
on standard post-operative visits. Intra-operative films or recordings and all patient data
may be saved and used according to HIPAA allowances.