Increased brain tumor resection using fluorescence image guidance in a preclinical model

Background and Objectives: Fluorescence image-guided brain tumor resection is thought to assist neurosurgeons by visualizing those tumor margins that merge imperceptibly into normal brain tissue and, hence, are difficult to identify. We compared resection completeness and residual tumor, determined by histopathology, after white light resection (WLR) using an operating microscope versus additional fluorescence guided resection (FGR). Study Design/Materials and Methods: We employed an intracranial VX2 tumor in a preclinical rabbit model and a fluorescence imaging/spectroscopy system, exciting and detecting the fluorescence of protoporphyrin IX (PpIX) induced endogenously by administering 5-aminolevulinic acid (ALA) at 4 hours before surgery. Results: Using FGR in addition to WLR significantly increased resection completeness by a factor 1.4 from 68 +/- 38 to 98 +/- 3.5%, and decreased the amount of residual tumor post-resection by a factor 16 from 32 +/- 38 to 2.0 +/- 3.5% of the initial tumor volume. Conclusions: Additional FGR increased completeness of resection and enabled more consistent resections between cases. Lasers Surg. Med. 35:181-190, 2004. (C) 2004 Wiley-Liss, Inc.