Esophageal-guided biopsy with volumetric laser endomicroscopy and laser cautery marking: a pilot clinical study

BackgroundBiopsy surveillance protocols for the assessment of Barrett's esophagus can be subject to sampling errors, resulting in diagnostic uncertainty. Optical coherence tomography is a cross-sectional imaging technique that can be used to conduct volumetric laser endomicroscopy (VLE) of the entire distal esophagus. We have developed a biopsy guidance platform that places endoscopically visible marks at VLE-determined biopsy sites.ObjectiveThe objective of this study was to demonstrate in human participants the safety and feasibility of VLE-guided biopsy in vivo.DesignA pilot feasibility study.SettingMassachusetts General Hospital.PatientsA total of 22 participants were enrolled from January 2011 to June 2012 with a prior diagnosis of Barrett's esophagus. Twelve participants were used to optimize the laser marking parameters and the system platform. A total of 30 target sites were selected and marked in real-time by using the VLE-guided biopsy platform in the remaining 10 participants.InterventionVolumetric laser endomicroscopy.Main Outcome MeasurementsEndoscopic and VLE visibility, and accuracy of VLE diagnosis of the tissue between the laser cautery marks.ResultsThere were no adverse events of VLE and laser marking. The optimal laser marking parameters were determined to be 2 seconds at 410 mW, with a mark separation of 6 mm. All marks made with these parameters were visible on endoscopy and VLE. The accuracies for diagnosing tissue in between the laser cautery marks by independent blinded readers for endoscopy were 67% (95% confidence interval [CI], 47%-83%), for VLE intent-to-biopsy images 93% (95% CI, 78%-99%), and for corrected VLE post-marking images 100% when compared with histopathology interpretations.LimitationsThis is a single-center feasibility study with a limited number of patients.ConclusionOur results demonstrate that VLE-guided biopsy of the esophagus is safe and can be used to guide biopsy site selection based on the acquired volumetric optical coherence tomography imaging data. (Clinical trial registration number: NCT01439633.)