In vivo measurements of diffuse reflectance and time-resolved autofluorescence emission spectra of basal cell carcinomas.
We present a clinical investigation of diffuse reflectance and time-resolved autofluorescence spectra of skin cancer with an emphasis on basal cell carcinoma. A total of 25 patients were measured using a compact steady-state diffuse reflectance/fluorescence spectrometer and a fibre-optic-coupled multispectral time-resolved spectrofluorometer. Measurements were performed in vivo prior to surgical excision of the investigated region. Singular value decomposition was used to reduce the dimensionality of steady state diffuse reflectance and fluorescence spectra. Linear discriminant analysis was then applied to the measurements of basal cell carcinomas (BCCs) and used to predict the tissue disease state with a leave-one-out methodology. This approach was able to correctly diagnose 87% of the BCCs. With 445 nm excitation a decrease in the spectrally averaged fluorescence lifetime was observed between normal tissue and BCC lesions with a mean value of 886 ps. Furthermore, the fluorescence lifetime for BCCs was lower than that of the surrounding healthy tissue in all cases and statistical analysis of the data revealed that this decrease was significant (p = 0.002).
Photonics Group, Department of Physics, Imperial College, Prince Consort Road, London, UK. alex.thompson08@imperial.ac.uk
Alex J
AJ
Thompson
Sergio
S
Coda
Mikkel Brydegaard
MB
Sørensen
Gordon
G
Kennedy
Rakesh
R
Patalay
Ulrika
U
Waitong-Brämming
Pieter A A
PA
De Beule
Mark A A
MA
Neil
Stefan
S
Andersson-Engels
Niels
N
Bendsøe
Paul M W
PM
French
Katarina
K
Svanberg
Chris
C
Dunsby
D002280:Basal Cell Carcinoma / Q000175:diagnosis*; D004058:Diffusion; D016002:Discriminant Analysis; D006801:Humans; D008027:Light; D010865:Pilot Projects; D012878:Skin Neoplasms / Q000175:diagnosis*; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*; D013997:Time Factors