Nonmelanoma skin cancers are the most common form of malignancy in humans. Between the traditional treatment ways, the photodynamic therapy (PDT) is a promising alternative which is minimally invasive and do not requires surgical intervention or exposure to ionizing radiation. The understanding of the cascade of effects playing role in PDT is not fully understood, so that define and understand the biochemical events caused by photodynamic effect will hopefully result in designing better PDT protocols. In this study we investigated the potential of the FTIR spectroscopy to assess the biochemical changes caused by photodynamic therapy after 10 and 20 days of treatment using 5-aminolevulinic acid (ALA) as precursor of the photosensitizer photoporphyrin IX (PpIX). The amplitude values of second derivative from vibrational modes obtained with FTIR spectroscopy showed similar behavior with the morphological features observed in histopathological analysis, which showed active lesions even 20 days after PDT. Thus, the technique has the potential to be used to complement the investigation of the main biochemical changes that photodynamic therapy promotes in tissue.

Date Published: 19 June 2015
PDF: 7 pages
Proc. SPIE 9531, Biophotonics South America, 95311J (19 June 2015); doi: 10.1117/12.2181067

Published in SPIE Proceedings Vol. 9531:
Biophotonics South America
Cristina Kurachi D.D.S.; Katarina Svanberg M.D.; Bruce J. Tromberg; Vanderlei Salvador Bagnato, Editor(s)