Abstract
INTRODUCTION
Recently, we use navigation-system guided biopsy with 5-ALA mediated photodynamic diagnosis (NGB-ALA-PDT) for brain tumor biopsies. Herein, the efficacy of the procedure was validated retrospectively.
METHODS
NGB-ALA-PDT was performed from January 2013 to March 2019 on 33 patients who were included in this study (70.0 ± 13.9 yo, male:female = 19:14). Preoperative multimodal images were used for the planning of the procedure. The Gd-enhanced lesions in magnetic resonance imaging (MRI) were set as the target. Four hours before the biopsy, the patients were administered 20 mg/kg of 5-ALA orally. Stealth station S7 (Medtronic Co., Ltd) was used for NGB. Immediately after the sampling, the red fluorescence of the samples was observed under excitation with violet-blue light through a low cut filter of neurosurgical microscope (Carl ZEISS, MITAKA Co Ltd). Additionally, with external LED blue light (Espelaruz; CCS Co, Ltd) excitation, the fluorescence was observed. The histological diagnosis, the operative position, the volume of the target, and complications were extracted from the records. The data were compared with that of 17 patients were performed flame guided biopsy (FGB) before the introduction of pNGB. In addition, the fluorescence with or without external blue light was compared.
RESULTS
Histological diagnosis included 20 diffuse large B-cell lymphomas (DLBCL), 9 malignant gliomas (MG), 2 metastatic brain tumors (Met), 1 inflammatory disease, and 1 demyelinated disease. There were no sampling errors. The target volume, the complication rate and sampling accuracy were same with FGB. The sensitivity of ALA-induced fluorescence and negative predictive value with external LED are improved compare with without external LED (sensitivity; 78.1% vs 40.6% and NPV; 12.5% vs 5.0%) No fluorescence was observed in 7 DLBCLs, 1 Met, and 1 inflammatory disease. In 11 cases included 1 none- or very-faint-fluorescence case, with the external LED, the visibility of the fluorescence was improved.
CONCLUSION
NGB is the safe and accurate procedure as FGB. The superiority of NGB is easy to choose surgical positions and followed with craniotomy immediately after biopsy. NGB-ALA-PDT with external excited LED light is useful for confirmation of accurate sampling.
Frameless free-hand navigation-guided biopsy for brain tumors: A simpler method with an endoscope holder
