ALA-induced PpIX spectroscopy for brain tumor image-guided surgery

Pablo A. Valdes, Frederic Leblond, Anthony Kim, Brent T. Harris, Brian C. Wilson, Keith D. Paulsen, David W. Roberts

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Maximizing the extent of brain tumor resection correlates with improved survival and quality of life outcomes in patients. Optimal surgical resection requires accurate discrimination between normal and abnormal, cancerous tissue. We present our recent experience using quantitative optical spectroscopy in 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) fluorescence-guided resection. Exogenous administration of ALA leads to preferential accumulation in tumor tissue of the fluorescent compound, PpIX, which can be used for in vivo surgical guidance. Using the state of the art approach with a fluorescence surgical microscope, we have been able to visualize a subset of brain tumors, but the sensitivity and accuracy of fluorescence detection for tumor tissue with this system are low. To take full advantage of the biological selectivity of PpIX accumulation in brain tumors, we used a quantitative optical spectroscopy system for in vivo measurements of PpIX tissue concentrations. We have shown that, using our quantitative approach for determination of biomarker concentrations, ALA-induced PpIX fluorescence-guidance can achieve accuracies of greater than 90% for most tumor histologies. Here we show multivariate analysis of fluorescence and diffuse reflectance signals in brain tumors with comparable diagnostic performance to our previously reported quantitative approach. These results are promising, since they show that technological improvements in current fluorescence-guided surgical technologies and more biologically relevant approaches are required to take full advantage of fluorescent biomarkers, achieve better tumor identification, increase extent of resection, and subsequently, lead to improve survival and quality of life in patients.

Original languageEnglish (US)
Title of host publicationPhotonic Therapeutics and Diagnostics VII
StatePublished - 2011
Externally publishedYes
EventPhotonic Therapeutics and Diagnostics VII - San Francisco, CA, United States
Duration: Jan 22 2011Jan 24 2011

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


ConferencePhotonic Therapeutics and Diagnostics VII
Country/TerritoryUnited States
CitySan Francisco, CA


  • 5-aminolevulinic acid
  • brain tumor
  • diffuse reflectance
  • fluorescence-guided resection
  • k-nearest neighbor
  • light-transport modeling
  • optical spectroscopy
  • protoporphyrin IX

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Biomaterials
  • Radiology Nuclear Medicine and imaging


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