# TISSUE LIGHT TRANSPORT & DOSAGE IN PHOTODYNAMIC

> **NIH NIH R01** · HENRY FORD HOSPITAL · 1990 · $79,083

## Abstract

This research project deals with the photophysics of photodynamic
therapy (PDT) utilizing coherent and noncoherent light and it's
tissue transport to PDT cancer treatment sites.  Our objectives are
to quantitate the processes of scatter, reflection, refraction and
absorbance in tissue and learn how these principles may be
utilized.  We have begun to develop procedures for the estimation
and delivery of a uniform, efficient photon light dosage so that
tumor oblation may occur without damage to normal tissue.  We have
studied the red region and the visible band from both laser and
incoherent sources, coupling laser beams to fiberoptics for
instillation and using beam expanders and incoherent sources for
external light delivery.  We have compiled transmittance and
spectral data on many mammalian tissues at PDT wavelengths, and for
the 400 to 1100 nm band have established penetration depths across
this region for several tissues.  We are extending this research.
Study has been carried out in tissue, on simulators, and with
tissue phantoms.  A series of mammalian tissues is being studied
across species boundaries.  Species similarities and variations
have been established.  This cross-species investigation continues
and will include human specimens during a later research phase.
The ultimate goal is establishment of a photon dosage prediction
system for all tissue, tumor types, for photon energies, and
sources.  We are developing a method of experimentally determining
space irradiance, describing the level and extent of light
diffusion through a three dimensional tissue volume.  Our
experimental results in three dimensions, to date, show a basic
exponential form.  This finding, which supports some of the
proposed theoretical models, developed by ourselves and others, is
the result of the first systematic series of measurements in 3-D
tissue volumes.  Additionally, work will be carried out
concurrently on a theoretical base for the prediction of transport
of light through tissue.  Applications of the diffusion and
Kubelka-Monk equations are being made to interpret our experimental
data.  We shall expand our determinations of tissue refraction for
selected wavelengths, and of scattering and adsorption
coefficients.  We have developed several computer programs to aid
in the experimental and theoretical work and they are now in use.
Basic data generated by this study will be used to develop a light
dosage planning system for PDT clinical use.

## Key facts

- **NIH application ID:** 3171504
- **Project number:** 5R01CA033727-06
- **Recipient organization:** HENRY FORD HOSPITAL
- **Principal Investigator:** FRED W HETZEL
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1990
- **Award amount:** $79,083
- **Award type:** 5
- **Project period:** 1984-01-01 → 1991-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3171504

## Citation

> US National Institutes of Health, RePORTER application 3171504, TISSUE LIGHT TRANSPORT & DOSAGE IN PHOTODYNAMIC (5R01CA033727-06). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3171504. Licensed CC0.

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