Development and characterization of multi-sensory fluence rate probes.
Multi-sensory fluence rate probes (MSPs) yield several simultaneous measurements of photodynamic therapy (PDT) treatment light fluence from a single interstitial probe. Fluorescent sensors are embedded at desired positions along the axis of the optical fibre. A single fluorescence emission spectrum is obtained and decomposed using a partial least squares (PLS)-based analysis to yield the fluence at each sensor's location. The responsivity, linearity and possible photodegradation of each fluorophore chosen for the MSPs were evaluated using single-sensor probes. The performance of two- and three-sensor MSPs was evaluated experimentally. Individual fluorescence spectra collected from each sensor on the MSP were used to construct the training set necessary for the PLS-based analysis. The MSPs' responsivity, spatial resolution and accuracy were evaluated relative to a single scattering-tip detector. Three-fluorophore MSPs permitted three simultaneous measurements of the fluence rate gradient in a tissue-like phantom, with an average accuracy of 6.7%. No appreciable photodegradation or cross-talk was observed.
Department of Medical Biophysics, University of Toronto, Toronto, Canada.
Natalie
N
Pomerleau-Dalcourt
Lothar
L
Lilge
D004867:Equipment Design; D005217:Fat Emulsions, Intravenous / Q000737:chemistry; D005240:Feasibility Studies; D005336:Fiber Optic Technology / Q000295:instrumentation*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D010778:Photochemotherapy / Q000295:instrumentation / Q000379:methods*; D012542:Scattering, Radiation
D005217:Fat Emulsions, Intravenous; D005456:Fluorescent Dyes