Abstract

Three instrumental measurement techniques: Laser Doppler Imaging (LDI), Digital Colour Photography (DCP) and Near InfraRed (NIR) spectroscopy were tested for their potential to objectively measure radiation-based erythema in breast cancer patients. The irradiation dose intervals were 0, 8-16, 18-26, 28-34, 36-44 and 46-50 Gy. In addition, two types of skin lotion for reducing erythema were tested on the patients and these were compared to using no lotion. The measured results had very skew distributions for all three techniques making nonparametric testing necessary. The Wilcoxon Signed Rank Sum Test (WSRST) was used for this purpose. LDI was performed to produce univariate average perfusion values leading to a perfusion increment ratio. These ratios showed a good sensitivity to erythema, with a median detection limit of 18 Gy. DCP was used to extract average red-green-blue (RG13) values that were used in multivariate models. Results for a combination of principal component score values showed a marked increase in median erythema from 8 Gy on. The multivariate data from NIR spectroscopy were data-reduced to principal component scores and combinations of these were tested. The score combinations were used to show median detection limits down to 8 Gy. The difference between the lotions and using no lotion gave no significant result for the WSRST paired comparison for any used measurement technique. (c) 2007 Elsevier B.V. All rights reserved.

Keywords

objective erythema measurement; multivariate data analysis; Wilcoxon nonparametric test; skin lotion; instrumentation

Published in

Chemometrics and Intelligent Laboratory Systems
2008, Volume: 90, number: 1, pages: 43-48
Publisher: ELSEVIER SCIENCE BV

SLU Authors

• Geladi, Paul

  • Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

SDG3 Ensure healthy lives and promote well-being for all at all ages


UKÄ Subject classification

Medical Laboratory and Measurements Technologies


Publication identifier

DOI: https://doi.org/10.1016/j.chemolab.2007.08.005

Permanent link to this page (URI)

https://res.slu.se/id/publ/17289