Development of a tissue-like protoporphyrin IX fluorescence phantom and performance of characterisation experiments

摘要: Background and Objective: Fluorescence spectroscopy is a potential tool for brain tumour resection surgery. The main advantages of fluorescence are the objective detection, possibility to quantify signals high sensitivity instance distinguish between healthy neoplastic tissue. This distinction difficult task attributed diffuse growth pattern tumour. A low dose 5- aminolevulinic acid (5- ALA) given orally patient. ALA promotes accumulation protporphyrin IX (PpIX) in cells which fluorescing substance. To measure emission neurosurgeon examines tissue with help an optical probe system developed at Department Biomedical Engineering Linkoping University. aim this study was develop phantom mimics allows measuring performing characterisation experiments controlled environment.Material methods: simulating black ink 20 % intralipid used obtain properties grade glioma each substance were measured collimated transmission compared data reported literature. Agar gel similar photobleaching Different PpIX concentrations added measurements performed. quantification as function concentration investigated. An algorithm established predict based on decay characteristics.Results: error ± 4 specified wavelength. ratio showed power integration time independent relationship while they linearly correlated (R2 = 0.79) could be quantified resolution μg ml-1. values among significant differences (p < 0.001) by using Kruskal-Wallis. Three parameters laser light pulsation, initial fluorophore excitation affected proportionally. can 9.2 %. times 63 loss intensity (9 s - 43 s) comparable clinical (19 39 s). With assumption that characteristics same already photobleached measurement reconstructed predicted.Conclusion: provides insight into detailed development process phantom. difference different concentrations. Furthermore, linear Additionally, kinetics vivo investigated method phantom, measurements, feasible from reasonable range but further investigations required.