Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published July 19, 1994 | Published
Book Section - Chapter Open

Light dosimetry in photodynamic therapy using optical fiber delivery

Abstract

This paper considers rapid calculations of light distributions in a tissue for photodynamic therapy. The delivery system considered is a single optical fiber, although other configurations are easily modeled. The influence of optical heterogeneities in the tissue is considered. The optical distributions surrounding an optical fiber within a tissue can be well approximated by a point source of light placed one 'reduced mean free path' (MFP) in front of the fiber tip. One MFP equals 1/(µ_a + µ_s(1-g)). Then the simple diffusion theory expression for 3D diffusion from a point source predicts the light distribution in the tissue. The influence of optical heterogeneities in the tissue can also be well approximated. A method is described for representing regions of increased absorption (such as a region with increased vascularity) as virtual sources of 'negative radiant power' such that linear superposition of the true primary source and the virtual sources yields the net light distribution in the heterogeneous tissue. The method is rapid, flexible, and generally accurate to within about 15% error. The method yields light distributions in optically complex issues.

Additional Information

© 1994 Society of Photo-Optical Instrumentation Engineers (SPIE). This work was supported by the Dept. of Energy (DE-FG05-91ER617226) and the NIH (R29-HL45045).

Attached Files

Published - 140.pdf

Files

140.pdf
Files (545.9 kB)
Name Size Download all
md5:173711c9443c5bbb4547c83f283f3e48
545.9 kB Preview Download

Additional details

Created:
August 20, 2023
Modified:
January 14, 2024