Fluorescence as a concept in colorectal lymph node diagnosis.

Area of Science:

• Oncology
• Medical Imaging
• Biophotonics

Background:

• Gastrointestinal cancers pose diagnostic challenges for lymphatic tumor spread.
• Current gamma-scintillation methods have limitations in sensitivity.
• Photodiagnostic tracers show potential for early cancer detection.

Purpose of the Study:

• To evaluate fluorescence detection as an alternative to gamma-scintillation for diagnosing lymphatic tumor spread in gastrointestinal cancers.
• To assess the sensitivity and specificity of fluorescence detection in identifying metastatic lymph nodes.
• To explore the utility of background-subtracting techniques and time-delayed fluorescence detection.

Main Methods:

• A pilot trial involving 174 lymph nodes from 9 colorectal cancer patients.
• Utilized comparative fluorescence detection techniques, including multi-wavelength observation and dual-wavelength excitation.
• Employed time-delayed fluorescence detection for enhanced sensitivity with long-lifetime fluorophores.
• Background-subtracting techniques were used to control for tissue autofluorescence.

Main Results:

• Metastatically involved lymph nodes were differentiated from non-involved nodes with 85% specificity and 65% sensitivity.
• Specific fluorescence features were observed in tumor-involved lymph nodes.
• The technique demonstrated potential for detecting small cell aggregates in lymph nodes.

Conclusions:

• Fluorescence detection, particularly with time-delayed techniques, is a viable method for diagnosing lymphatic tumor spread in gastrointestinal cancers.
• This approach may improve the sensitivity of detecting small metastatic deposits compared to traditional methods.
• Specific fluorescence characteristics can aid in preselecting tissue samples for histological analysis, optimizing diagnostic workflows.