Monitoring blood volume and saturation using superficial fibre optic reflectance spectroscopy during PDT of actinic keratosis

✍ Scribed by Tom A. Middelburg; Stephen C. Kanick; Ellen R. M. de Haas; Henricus J. C. M. Sterenborg; Arjen Amelink; Martino H. A. M. Neumann; Dominic J. Robinson

• Book ID: 102871465
• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 785 KB
• Volume: 4
• Category: Article
• ISSN: 1864-063X
• DOI: 10.1002/jbio.201100053

✦ Synopsis

Abstract

Optically monitoring the vascular physiology during photodynamic therapy (PDT) may help understand patient‐specific treatment outcome. However, diffuse optical techniques have failed to observe changes herein, probably by optically sampling too deep. Therefore, we investigated using differential path‐length spectroscopy (DPS) to obtain superficial measurements of vascular physiology in actinic keratosis (AK) skin. The AK‐specific DPS interrogation depth was chosen up to 400 microns in depth, based on the thickness of AK histology samples. During light fractionated aminolevulinic acid‐PDT, reflectance spectra were analyzed to yield quantitative estimates of blood volume and saturation. Blood volume showed significant lesion‐specific changes during PDT without a general trend for all lesions and saturation remained high during PDT. This study shows that DPS allows optically monitoring the superficial blood volume and saturation during skin PDT. The patient‐specific variability supports the need for dosimetric measurements. In DPS, the lesion‐specific optimal interrogation depth can be varied based on lesion thickness. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)