Abstract
PURPOSE: We engineered a flexible fiber-optic microendoscope for longitudinal optical imaging studies in a mouse model of disseminated ovarian cancer. PROCEDURES: The microendoscope delivers 470 nm excitation light from a light-emitting diode through a fiber-optic bundle with outer diameter of 680 μm. Optics were optimized to maximize power and lateral resolution. We used this instrument to repetitively monitor intraperitoneal growth of HeyA8 ovarian cancer cells stably transduced with green fluorescent protein over 4 weeks. RESULTS: The microendoscope achieves 0.7 mW power and lateral resolution of 4 μm. Initial in vivo imaging studies visualized single cells and small clusters of malignant cells with subsequent studies showing tumor masses and vasculature. We also resolved single cells within intraperitoneal tumor masses. CONCLUSIONS: These studies establish microendoscope technology with single cell resolution for minimally-invasive, longitudinal imaging in living animals. This technology will advance future molecular imaging studies of ovarian cancer and other diseases.