Photobleaching behavior of protoporphyrin IX during 5-aminolevulinic acid marked glioblastoma detection
2009 (English)In: Photonic Therapeutics and Diagnostics V / [ed] Nikiforos Kollias; Bernard Choi; Haishan Zeng; Reza S. Malek; Brian J. Wong; Justus F. R. Ilgner; Kenton W. Gregory; Guillermo J. Tearney; Laura Marcu; Henry Hirschberg; Steen J. Madsen, SPIE - International Society for Optical Engineering, 2009, 716131-1-716131-8 p.Conference paper (Other academic)
The highly malignant brain tumor, glioblastoma multiforme (GBM), is difficult to fully delineate during surgical resection due to its infiltrative ingrowth and morphological similarities to surrounding functioning brain tissue. Selectiveness of GBM to 5-aminolevulinic acid (5-ALA) induced protoporphyrin IX (PpIX) is reported by other researchers to visualize tumor margins under blue light microscopy. To allow objective detection of GBM, a compact and portable fiber optic based fluorescence spectroscopy system is developed. This system is able to deliver excitation laser light (405 nm) in both the continuous and pulsed mode. PpIX fluorescence peaks are detected at 635 and 704 nm, using a fiber-coupled spectrometer. It is necessary to optimize the detection efficiency of the system as the PpIX quickly photobleaches during the laser illumination. A light dose of 2.5 mJ (fluence rate = 9 mJ/mm2) is experimentally approved to excite an acceptable level of fluourescence signal arising from glioblastoma. In pulsed illumination mode, an excitation dose of 2.5 mJ, with a dark interval of 0.5 s (duty cycle 50%) shows a significantly shorter photobleaching time in comparison to the continuous illumination mode with the same laser power (p < 0.05). To avoid photobleaching (the remaining signal is more than 90% of its initial value) when measuring with 2.5 mJ delivered energy, the time for continuous and pulsed illumination should be restricted to 2.5 and 1.1 s, respectively.
Place, publisher, year, edition, pages
SPIE - International Society for Optical Engineering, 2009. 716131-1-716131-8 p.
, Proceedings of SPIE (Progress in biomedical optics and imaging), ISSN 1605-7422 ; 7161
Photobleaching, glioblastoma multiforme, 5-aminolevulinic acid induced protoporphyrin IX
Biomedical Laboratory Science/Technology
IdentifiersURN: urn:nbn:se:liu:diva-19938DOI: 10.1117/12.808156ISI: 000285713200060ISBN: 9780819474070OAI: oai:DiVA.org:liu-19938DiVA: diva2:231849
Photonic Therapeutics and Diagnostics V, 24 January 2009, San Jose, CA, USA
Copyright 2009 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. The original publication is: Neda Haj-Hosseini, Johan Richtera, Stefan Andersson-Engels and Karin Wårdell, Photobleaching behavior of protoporphyrin IX during 5-aminolevulinic acid marked glioblastoma detection, 2009, Proceedings of SPIE, (7161), 716131. http://dx.doi.org/10.1117/12.8081562009-08-182009-08-172016-08-31