IMAGING OF ILLUMINATED TISSUE DURING THE PHOTODYNAMIC PROCESS BY PHOTOSENSITIZED BOLD MRI
Brami C, Pinkas I, Scherz A, Salomon Y
The Weizmann Institute of Science
Vascular targeting photodynamic therapy (VTP) of tumors with circulating Pd-bacteriochlorophyll derivatives is presently in phase II clinical trials for prostate cancer. Its mechanism is based on intravascular light-dependent generation of cytotoxic ROS. Consequent accumulation of paramagnetic deoxyhemoglobin and blood stasis were reported by us as intrinsic markers for online monitoring of VTP by photosensitized fMRI. Here we newly demonstrate that upon application of short light flashes, coincidental BOLD contrast pulses trace the illuminated area, thereby signifying that BOLD MRI is capable of imaging the boundaries of the illuminated region in the tissue. Supported by STEBA BIOTECH and NEGMA LERADS, France.