Interstitial light application for photodynamic therapy in a rat brain tumor model

Even Angell-Petersen; Dag R. Sorensen V.D.M.; Steen J. Madsen; Henry Hirschberg M.D.

doi:10.1117/12.527417

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13 July 2004 Interstitial light application for photodynamic therapy in a rat brain tumor model

Even Angell-Petersen, Dag R. Sorensen V.D.M., Steen J. Madsen, Henry Hirschberg M.D.

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Proceedings Volume 5312, Lasers in Surgery: Advanced Characterization, Therapeutics, and Systems XIV; (2004) https://doi.org/10.1117/12.527417
Event: Biomedical Optics 2004, 2004, San Jose, CA, United States

Abstract

The usefulness of repetitive ALA mediated PDT is being evaluated in a rat brain tumor model. In preliminary experiments an optical fiber was repeatedly introduced directly into the brain to apply light, requiring multiple surgical procedures. In an attempt to refine the animal model, an indwelling light applicator, using a modified microdialysis guide cannula has been developed. The cannula is fixed to the scull and can remain in the rat brain for several weeks without complications. In studies of repetitive PDT the need for repeated mounting in a stereotactic frame and surgical procedures can be eliminated. The applicator also makes it feasible to employ low fluence rates with long treatment times, which correspond to future clinically relevant protocols. The fluence rate distribution was measured in vivo and compared to diffusion theory and Monte Carlo simulations to estimate the tissue optical properties of the rat brain for light at 632 nm. The modeling suggested a reduced scattering coefficient 38 cm^-1, an absorption coefficient 0.46 cm^-1 and a penetration depth 0.14 cm.

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Even Angell-Petersen, Dag R. Sorensen V.D.M., Steen J. Madsen, and Henry Hirschberg M.D. "Interstitial light application for photodynamic therapy in a rat brain tumor model", Proc. SPIE 5312, Lasers in Surgery: Advanced Characterization, Therapeutics, and Systems XIV, (13 July 2004); https://doi.org/10.1117/12.527417

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