Performance evaluation of the LightPath imaging system for intra-operative Cerenkov luminescence imaging

The performances of an intra-operative optical imaging system for Cerenkov luminescence imaging of resected tumor specimens were evaluated with phantom studies. The spatial resolution, the linearity of the measured signal with the activity concentration and the minimum detectable activity concentration were considered. A high linearity was observed over a broad range of activity concentration (R2⩾0.99 down to ∼40 kBq/ml of 18F-FDG). For 18F-FDG activity distributions 2 mm deep in biological tissue, the measured detection limit was 8 kBq/ml and a spatial resolution of 2.5 mm was obtained. The detection limit of the imaging system is comparable with clinical activity concentrations in tumor specimens, and the spatial resolution is compatible with clinical requirements.