AUTHOR=Nie Zhaojun , Yeh Shu-Chi Allison , LePalud Michelle , Badr Fares , Tse Frances , Armstrong David , Liu Louis W. C. , Deen M. Jamal , Fang Qiyin TITLE=Optical Biopsy of the Upper GI Tract Using Fluorescence Lifetime and Spectra JOURNAL=Frontiers in Physiology VOLUME=Volume 11 - 2020 YEAR=2020 URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2020.00339 DOI=10.3389/fphys.2020.00339 ISSN=1664-042X ABSTRACT=Screening and surveillance for gastrointestinal (GI) cancers by endoscope guided biopsy are invasive, time-consuming, and has the potential for sampling error. Endogenous fluorescence spectra of tissue containing biochemical and physiological information that may enable real-time, objective diagnosis when combined with endoscopic images. We first briefly reviewed optical biopsy modalities for GI cancer diagnosis with a focus on fluorescence-based techniques. In an ex vivo pilot clinical study, we measured fluorescence spectra and lifetime on fresh biopsy specimens obtained during routine upper GI screening procedures. Our results demonstrated the feasibility of rapid acquisition of time-resolved fluorescence spectra from fresh GI mucosal specimens. We also identified spectroscopic signatures that differentiate normal mucosa from the esophagus, stomach, and duodenum.