Precise Tumor Delineation via Dual Fluorescence Lifetime Imaging.

Area of Science:

• Biomedical Optics
• Nanotechnology
• Medical Imaging

Background:

• Accurate tumor margin delineation is vital for successful surgical resection and patient outcomes.
• Traditional fluorescence imaging methods struggle with precise boundary visualization, often leading to inconsistencies.
• Near-infrared IIb (NIR-IIb) fluorescence imaging offers high sensitivity and resolution but faces challenges in boundary definition.

Purpose of the Study:

• To develop an improved fluorescence imaging technique for precise tumor boundary delineation.
• To overcome the limitations of traditional fluorescence imaging in defining tumor margins.
• To establish a reliable method for intraoperative assessment of tumor resection margins.

Main Methods:

• Developed a dual-fluorescence lifetime imaging (FLIM) approach utilizing Er-based lanthanide-doped nanoparticles (LnNPs).
• Synthesized two types of LnNPs: 0%Tm@NaYF4-PEG-HA for tumor targeting and 1.5%Tm@NaYF4-PEG for normal tissue staining.
• Utilized distinct fluorescence lifetimes of the LnNPs in the NIR-IIb window (1500-1700 nm) for differential tissue visualization.

Main Results:

• The dual-FLIM approach successfully differentiated tumor from surrounding normal tissues based on distinct fluorescence lifetimes.
• Achieved clear visualization of tumor margins, overcoming inconsistencies associated with traditional imaging parameters.
• Demonstrated that 1.5%Tm@NaYF4-PEG exhibits a shorter NIR-IIb fluorescence lifetime due to Er3+-Tm3+ energy transfer.

Conclusions:

• The developed dual-FLIM method provides accurate and reliable tumor boundary delineation.
• This technique eliminates subjective parameter dependency, enhancing the consistency of margin assessment.
• Offers a promising solution for intraoperative margin evaluation, potentially improving surgical precision and treatment efficacy.