Real-time IR700 Fluorescence Imaging During Near-infrared Photoimmunotherapy Using a Clinically-approved Camera for Indocyanine Green
Shuhei Okuyama, Daiki Fujimura, Fuyuki Inagaki, Ryuhei Okada, Yasuhiro Maruoka, Hiroaki Wakiyama, Takuya Kato, Aki Furusawa, Peter L. Choyke, Hisataka Kobayashi
Abstract
Background/Aim: Near-infrared photoimmuno-therapy (NIR-PIT) is a newly approved cancer phototherapy. We aim to confirm whether a clinically approved camera for indocyanine green (ICG) could monitor IR700 fluorescence in real time during exposure to therapeutic NIR light. Materials and Methods: An NIR camera, LIGHTVISION, designed to image ICG fluorescence, was used. A431-GFP/luc tumor-bearing mice were exposed to therapeutic NIR light and real-time fluorescence imaging (RT-FI) was obtained and measured with LIGHTVISION. Bioluminescence imaging (BLI) was performed to confirm cell death. Results: . Correlation between BLI and IR700 fluorescence loss showed that loss of fluorescence was associated with increased cell death. Conclusion: The efficacy of NIR-PIT could be monitored non-invasively and in real-time using weak fluorescence at wavelengths much longer than the peak fluorescence of IR700. This technique can achieve precise light dosimetry that allows us to decide on the optimal exposure.