Selective sampling using confocal Raman spectroscopy provides enhanced specificity for urinary bladder cancer...

Area of Science:

• Biomedical Optics
• Cancer Diagnostics
• Spectroscopy

Background:

• Raman spectroscopy shows promise for bladder cancer diagnosis due to its molecular specificity.
• Current high-volume Raman probes lack the specificity needed for widespread clinical use.
• Existing methods like photodynamic diagnosis have limitations in reducing false detection rates.

Purpose of the Study:

• To engineer and apply a confocal Raman probe to enhance bladder cancer diagnostic specificity.
• To develop a diagnostic algorithm for distinguishing cancerous from normal bladder tissue using confocal Raman spectroscopy.
• To evaluate the sensitivity and specificity of the confocal Raman probe approach compared to high-volume probes.

Main Methods:

• Engineered a confocal Raman probe with a depth of field of approximately 280 μm.
• Acquired ex vivo Raman spectra from normal and cancerous transurethral resection of bladder tumor (TURBT) samples.
• Developed a diagnostic algorithm utilizing principal component analysis and logistic regression.

Main Results:

• The confocal Raman probe approach achieved significantly higher specificity compared to high-volume probes.
• Sensitivity was comparable to existing methods, while specificity was markedly improved.
• The diagnostic algorithm, using only two principal components, demonstrated robust sample discrimination.
• The method showed reproducible results, with no discordance between replicate spectra.

Conclusions:

• A confocal Raman probe can significantly boost the specificity of bladder cancer diagnosis by suppressing out-of-focus signals.
• This technology offers a promising complementary tool for real-time guidance during endoscopic procedures for bladder cancer.
• The high sensitivity and specificity achieved pave the way for clinical translation in bladder cancer diagnosis and treatment.