S99 Fluorescence-lifetime imaging: a novel diagnostic tool for suspected lung cancer

Introduction and ObjectivesLung cancer is the commonest cause of cancer-related deaths. Early detection improves outcomes, however, the diagnostic yield of existing sampling techniques is suboptimal. Fluorescence-lifetime imaging microscopy (FLIM), an autofluorescence-based technique which measures endogenous fluorophore decay rates, may aid identification of optimal biopsy sites in suspected lung cancer. We describe the application of a novel fibre-based FLIM system, which utilises 488nm excitation to enable fluorescence intensity and lifetime imaging, to detect changes in freshly resected lung cancer and adjacent healthy tissue. The mechanisms responsible for alterations in lung cancer fluorescence lifetime are not understood. We investigate the contributions of cancer cells and tumour stroma to fluorescence lifetime signatures using fixed unstained lung cancer and benchtop FLIM.MethodsPaired cancer and non-cancerous lung tissues were obtained from resection patients (n=21). A 488nm fibre-based FLIM platform was used to perform high-resolution fluorescence intensity and lifetime imaging (figure 1). Co-registered fixed unstained lung cancer sections were evaluated using benchtop FLIM and image analysis software.ResultsFluorescence lifetime is significantly reduced in fresh ex vivo lung cancer, compared with non-cancerous tissue (mean±SD, 2.15±0.26ns vs. 1.79±0.40ns, p