Detection of a Water-Soluble Hypericin Formulation in Glioblastoma Tissue with Fluorescence Lifetime and Intensity...

Area of Science:

• Neuro-oncology
• Biomedical Imaging
• Photodynamic Therapy

Background:

• High hypericin-loaded polyvinylpyrrolidone (HHL-PVP) offers an orally bioavailable formulation for hypericin's use in brain tumor photodynamic diagnosis (PDD) and therapy (PDT).
• Distinguishing HHL-PVP fluorescence from 5-Aminolevulinic acid (5-ALA) fluorescence is crucial for its clinical application in glioblastoma surgery.

Purpose of the Study:

• To evaluate a Complementary Metal-Oxide-Semiconductor (CMOS) camera system with a hypericin-specific filter for selective HHL-PVP visualization in glioblastoma.
• To assess the system's ability to differentiate HHL-PVP fluorescence from 5-ALA induced fluorescence.

Main Methods:

• Utilized a CMOS camera system with a standard filter for 5-ALA and a novel hypericin-specific filter (575-615 nm).
• Analyzed ex vivo glioblastoma specimens from 12 patients, incubated with HHL-PVP.
• Measured fluorescence intensity and lifetime changes before and after HHL-PVP incubation and rinsing.

Main Results:

• The hypericin-specific filter demonstrated statistically significant increases in fluorescence intensity (p=0.001) and lifetime (p=0.028) post-HHL-PVP incubation.
• No significant signal differences were observed with the non-hypericin specific filter.
• HHL-PVP treated specimens were identified with 87.5% sensitivity and 100% specificity.

Conclusions:

• A CMOS camera system with a hypericin-specific filter can selectively visualize HHL-PVP in glioblastoma tissue.
• This technique holds potential for future clinical studies of HHL-PVP in PDD and PDT.
• It may complement existing 5-ALA based surgical guidance.