Rapid imaging and detection of circulating tumor cells using a wide-field fluorescence imaging system

Circulating tumor cells (CTCs) provide potentially accessible in vivo sources of metastatic cancer cells. As such, considerable focus has been placed on analyzing the genetics of single-CTCs. Prior to these analyses, however, CTCs must first be detected within the blood samples of cancer patients. Current methods for detection of CTCs by fluorescence microscopy require the analysis of hundreds of images per blood sample, making this a time-consuming process that creates a bottleneck in CTC analysis. In this study, we therefore developed a wide-field fluorescence imaging system for rapid CTC detection. For these analyses, CTCs were first isolated using the microcavity array (MCA), a micro-sized filter for CTC recovery that separates cells based on differences in cell size and deformability. Notably, the proposed imaging system enabled rapid (∼10 s) visualization of all stained cells within the 6 mm × 6 mm MCA field via one-shot imaging. Furthermore, the morphology of the cells in the resulting images accurately reflected that observed by conventional microscopy. In total, isolation and detection of CTCs using the MCA combined with our novel wide-field fluorescence imaging system was achieved within 1 h. Thus, our proposed system will provide rapid CTC detection system.