The use of fluorescence imaging for aiding oncologic surgery is a fast growing field in biomedical imaging, revolutionizing
open and minimally invasive surgery practices. We have designed, constructed, and tested a system for fluorescence image
acquisition and direct display on the surgical field for fluorescence guided surgery. The system uses a near-infrared
sensitive CMOS camera for image acquisition, a near-infra LED light source for excitation, and DLP digital projector for
projection of fluorescence image data onto the operating field in real time. Instrument control was implemented in Matlab
for image capture, processing of acquired data and alignment of image parameters with the projected pattern. Accuracy
of alignment was evaluated statistically to demonstrate sensitivity to small objects and alignment throughout the imaging
field. After verification of accurate alignment, feasibility for clinical application was demonstrated in large animal models
of sentinel lymph node biopsy. Indocyanine green was injected subcutaneously in Yorkshire pigs at various locations to
model sentinel lymph node biopsy in gynecologic cancers, head and neck cancer, and melanoma. Fluorescence was
detected by the camera system during operations and projected onto the imaging field, accurately identifying tissues
containing the fluorescent tracer at up to 15 frames per second. Fluorescence information was projected as binary green
regions after thresholding and denoising raw intensity data. Promising results with this initial clinical scale prototype
provided encouraging results for the feasibility of optical projection of acquired luminescence during open oncologic
surgeries.
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