Thermally determined excitation power limits for fiber-based fluorescence diagnosis based on ICG and PpIX

Objective: For fluorescence-guided stereotactic brain tumor biopsy via fiber-based fluorescence detection of protoporphyrin IX (PpIX) (typ. excitation at 405nm, emission at 633nm) which selectively accumulates in tumor tissue, an additional method for simultaneous blood vessel detection ahead of the distal fiber end shall be developed in order to minimize the risk of blood vessel perforation. For this purpose, the infrared fluorescence of the intraveneously administered intraluminal fluorophore indocyanin-green (ICG) (typ. excitation at 785nm, emission at 835nm) shall be detected through the same fiber-optic sys…