Novel Wavelength-Specific Blue Light-Emitting Headlamp for 5-Aminolevulinic Acid Fluorescence-Guided Resection of Glioblastoma.

Abstract

Extent of resection of glioblastoma is an important predictor for overall survival, and 5-aminolevulinic acid fluorescence-guided surgery can improve outcomes. However, the technique requires the installation of a blue light module on operative microscopes and may be cost prohibitive. A novel and economical blue light-emitting headlamp was designed, and its clinical utility was explored. A remote-controlled dual light emitting diode headlamp system was constructed with 1 diode emitting white light and the other blue. Spectrographic analysis of the blue light emitted from a commercial operative microscope and the headlamp was performed. A comparative evaluation of the 2 illumination systems was conducted for 3 patients who underwent craniotomy for glioblastoma resection. Histologic examination of the fluorescing tissue detected by the headlamp was performed, and the extent of resection was assessed by postoperative day 1 magnetic resonance imaging. Spectrography of blue light emitted from the headlamp system was wavelength specific with a single emission peak at 416 nm and a linewidth of 35 nm. In contrast, blue light from the microscope (peak: 426 nm) had a wider linewidth of 54 nm and was not wavelength specific with additional infrared radiation detected. Gross or near-total resection of contrast-enhancing glioblastoma was performed for all 3 patients. Intraoperatively, comparable tumor fluorescence was observed under microscope and headlamp blue light illumination. Histologic examination of tissue fluorescing under headlamp blue light confirmed the presence of glioblastoma. This novel proof-of-concept blue light-emitting headlamp device may offer an opportunity for institutions with limited resources to implement 5-aminolevulinic acid fluorescence-guided glioblastoma resections.