Navigation-guided endoscopic biopsy for intraparenchymal brain tumor.

To evaluate the efficacy of intraparenchymal brain tumor biopsy using endoscopy and a navigation system (navigation-guided endoscopic biopsy) as a diagnostic tool, a case series of intraparenchymal tumor biopsies was reviewed. Navigation-guided endoscopic biopsy was applied in 9 cases, stereotactic needle biopsy in 16 cases, and open biopsy with or without navigation system in 34 cases. In all biopsy cases, 84.7% of biopsy points were sampled accurately, and 93.2% of diagnoses by biopsy were correct. Comparison of each type of biopsy showed that the resected volumes in navigation-guided endoscopic biopsy and open biopsy tended to be larger than those in stereotactic biopsy, and the mean operation time for the open biopsy procedure was the longest. To define the most applicable device or examination method to increase sampling accuracy, various factors were analyzed in 59 procedures. Navigation-guided endoscopic biopsy was the most accurate of the three types of biopsy, although the statistical difference was not significant. Older patients, histological diagnosis of high-grade glioma or malignant lymphoma, positive photodynamic diagnosis, and positive intraoperative pathology were significant factors in improving the sampling accuracy. Navigation-guided endoscopic biopsy could provide a larger sample volume within a relatively short operation time. The biopsy can be easily combined with both photodynamic diagnosis and intraoperative pathology, significantly improving the histological diagnostic yield.