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Updated: Dec 20, 2025
An Orthotopic Bladder Tumor Model and the Evaluation of Intravesical saRNA Treatment
Published on: July 28, 2012
Two diagnostic criteria of optical spectroscopy for bladder tumor detection: Clinical study using 5-ALA induced
Nina Kalyagina1, Maxim Loshchenov2, Marine Amouroux3
1Prokhorov General Physics Institute, Russian Academy of Sciences, Vavilov Str. 38, Moscow 119991, Russia; National Research Nuclear University MEPhI, Kashirskoye Shosse 31, Moscow 115409, Russia.
Background:
The study proposes to improve bladder cancer diagnosis by photodynamic diagnosis (PDD) using red-light excitation (632.8 nm) of 5-ALA induced-protoporphyrin IX. Employing 9 patients' bladders, two types of signals were used to improve diagnostic accuracy for malignancy and we also present numerical modeling of the scattering coefficient to provide biological explanation of the results obtained.
Methods:
Two modalities of bladder cancer spectral diagnosis are presented: conventional PDD and intensity assessment of the diffusely reflected laser light by fiber-optic spectroscopy. Experiments are done in clinical conditions and as a series of numerical simulations.
Results:
High-grade cancerous bladder tissues display twice a higher relative fluorescence intensity (mean value 1, n = 9) than healthy (0.39, n = 9), dysplastic (0.44, n = 5) tissues and CIS (0.39, n = 2). The laser back-scattering signal allows to discriminate most effectively high-grade cancerous and dysplastic tissues from normal. Numerical modeling of diffuse reflectance spectra reveals that spectral behavior of the back-scattered light depends on both, nuclear size and nuclear density of tumoral cells.
Conclusions:
Unlike the fluorescence signal, where its value is higher in the case of pathological tissues, the tendency of the laser signal to, both, decrease or increase in comparison with the signal from normal urothelium, should be perceived as a sign towards neoplasm. Numerical simulation reveals that such a double-analysis at a multiwavelength mode potentially may be used to provide diagnostic accuracy.
