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Proceedings Paper

An intraoperative spectroscopic imaging system for quantification of Protoporphyrin IX during glioma surgery (Conference Presentation)
Author(s): Leticia M. Angulo-Rodríguez; Audrey Laurence; Michael Jermyn; Guillaume Sheehy; Mira Sibai; Kevin Petrecca; David W. Roberts; Keith D. Paulsen; Brian C. Wilson; Frédéric Leblond

Paper Abstract

Cancer tissue often remains after brain tumor resection due to the inability to detect the full extent of cancer during surgery, particularly near tumor boundaries. Commercial systems are available for intra-operative real-time aminolevulenic acid (ALA)-induced protoporphyrin IX (PpIX) fluorescence imaging. These are standard white-light neurosurgical microscopes adapted with optical components for fluorescence excitation and detection. However, these instruments lack sensitivity and specificity, which limits the ability to detect low levels of PpIX and distinguish it from tissue auto-fluorescence. Current systems also cannot provide repeatable and un-biased quantitative fluorophore concentration values because of the unknown and highly variable light attenuation by tissue. We present a highly sensitive spectroscopic fluorescence imaging system that is seamlessly integrated onto a neurosurgical microscope. Hardware and software were developed to achieve through-microscope spatially-modulated illumination for 3D profilometry and to use this information to extract tissue optical properties to correct for the effects of tissue light attenuation. This gives pixel-by-pixel quantified fluorescence values and improves detection of low PpIX concentrations. This is achieved using a high-sensitivity Electron Multiplying Charge Coupled Device (EMCCD) with a Liquid Crystal Tunable Filter (LCTF) whereby spectral bands are acquired sequentially; and a snapshot camera system with simultaneous acquisition of all bands is used for profilometry and optical property recovery. Sensitivity and specificity to PpIX is demonstrated using brain tissue phantoms and intraoperative human data acquired in an on-going clinical study using PpIX fluorescence to guide glioma resection.

Paper Details

Date Published: 26 April 2016
PDF: 1 pages
Proc. SPIE 9690, Clinical and Translational Neurophotonics; Neural Imaging and Sensing; and Optogenetics and Optical Manipulation, 96900F (26 April 2016); doi: 10.1117/12.2213367
Show Author Affiliations
Leticia M. Angulo-Rodríguez, Ecole Polytechnique de Montréal (Canada)
Audrey Laurence, Ecole Polytechnique de Montréal (Canada)
Michael Jermyn, Ecole Polytechnique de Montréal (Canada)
Montreal Neurological Institute and Hospital (Canada)
Guillaume Sheehy, Ecole Polytechnique de Montréal (Canada)
Mira Sibai, Princess Margaret Cancer Ctr. (Canada)
Univ. of Toronto (Canada)
Kevin Petrecca, Montreal Neurological Hospital and Institute (Canada)
David W. Roberts, Dartmouth Hitchcock Medical Ctr. (United States)
Keith D. Paulsen, Thayer School of Engineering at Dartmouth (United States)
Brian C. Wilson, Princess Margaret Cancer Ctr. (Canada)
Univ. of Toronto (Canada)
Frédéric Leblond, Ecole Polytechnique de Montréal (Canada)


Published in SPIE Proceedings Vol. 9690:
Clinical and Translational Neurophotonics; Neural Imaging and Sensing; and Optogenetics and Optical Manipulation
Steen J. Madsen; E. Duco Jansen; Samarendra K. Mohanty; Nitish V. Thakor; Qingming Luo; Victor X. D. Yang, Editor(s)

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