An optical method for reducing green fluorescence from urine during fluorescence-guided cystoscopy

Area of Science:

• Urology
• Medical Optics
• Cancer Diagnostics

Background:

• Photodynamic diagnosis (PDD) enhances bladder cancer detection and treatment, reducing recurrence.
• Blue light used in PDD causes green urine fluorescence, confounding red tumor fluorescence.
• Current methods struggle with urine fluorescence, especially in flexible cystoscopy.

Purpose of the Study:

• To develop and evaluate a novel LED light source for fluorescence-assisted bladder tumor detection.
• To overcome the challenge of urine-induced green fluorescence in PDD.
• To improve tumor visualization in both flexible and rigid cystoscopy.

Main Methods:

• Development of a tailor-made, high-power LED light source emitting at 525 nm.
• In vitro and in vivo testing of the LED light source with flexible and rigid cystoscopes.
• Evaluation of the light source's effect on urine fluorescence and tumor visualization.

Main Results:

• The 525 nm LED light source significantly reduced confounding green fluorescence from urine.
• The light source facilitated clear visualization of tumor fluorescence in both flexible and rigid cystoscopes.
• Healthy bladder mucosa exhibited autofluorescence, providing contrast with tumor fluorescence.

Conclusions:

• A 525 nm LED light source offers a viable solution to the urine fluorescence problem in PDD.
• This technology improves fluorescence-assisted tumor detection in both outpatient and operating room settings.
• The dual capability of reducing urine fluorescence and enhancing tumor contrast holds promise for improved bladder cancer diagnosis.