Changes in human skin after topical PDT with hexyl aminolevulinate

Juzeniene, Asta; Nielsen, Kristian Pagh; Zhao, Lu; Ryzhikov, Gennady A.; Biryulina, Marina S.; Stamnes, Jakob J.; Stamnes, Knut; Moan, Johan

doi:10.1016/j.pdpdt.2008.07.001

« Previous Next »Photodiagnosis and Photodynamic Therapy
Volume 5, Issue 3 , Pages 176-181, September 2008

Changes in human skin after topical PDT with hexyl aminolevulinate

Asta Juzeniene
- Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Rikshospitalet University Hospital, Montebello, 0310 Oslo, Norway
- Corresponding author. Tel.: +47 22935113; fax: +47 22934270.
Kristian Pagh Nielsen
- Balter Medical AS, Thormøhlensgt. 55, N-5008 Bergen, Norway
Lu Zhao
- Balter Medical AS, Thormøhlensgt. 55, N-5008 Bergen, Norway
Gennady A. Ryzhikov
- Balter Medical AS, Thormøhlensgt. 55, N-5008 Bergen, Norway
Marina S. Biryulina
- Balter Medical AS, Thormøhlensgt. 55, N-5008 Bergen, Norway
Jakob J. Stamnes
- Balter Medical AS, Thormøhlensgt. 55, N-5008 Bergen, Norway
- Department of Physics and Technology, University of Bergen, Allégt. 55, 5007 Bergen, Norway
Knut Stamnes
- Department of Physics and Engineering Physics, Light and Life Laboratory, Stevens Institute of Technology, Castle Point on Hudson, NJ, USA
Johan Moan
- Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Rikshospitalet University Hospital, Montebello, 0310 Oslo, Norway
- Institute of Physics, University of Oslo, Blindern, 0316 Oslo, Norway

published online 29 August 2008.

Summary

Background

Photodynamic therapy (PDT) induces physiological changes in human skin, but details and kinetics are not known.

Methods

Changes in human skin induced by PDT with red light in the presence of topically applied cream with the hexyl aminolevulinate (HAL) were investigated in the skin of five healthy volunteers. In addition to testing the effects of HAL-PDT three control studies were performed on the volunteers: (A) the HAL containing cream was applied to the skin without light exposure; (B) the cream without HAL was applied to the skin; (C) the skin was exposed to light in the absence of the cream. Reflectance spectra of the skin were measured in the wavelength region 300–600nm before and after treatment. An advanced and new inverse radiative transfer model was used to determine changes induced in a number of skin parameters.

Results

The main discoveries were that the dermal blood concentration increased immediately after PDT, reached a maximum after 1–2 days, and then decreased. The blood oxygenation increased significantly immediately after PDT and then decreased. After PDT the melanosome concentration in the upper epidermis increased steadily. No such changes were observed in the control sites.