***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Radiofrequency ablation ( RFA ) is an endoscopic technique used to eradicate Barrett 's esophagus ( BE ) . However , such ablation can commonly lead to neosquamous epithelium overlying residual BE gl and s not visible by conventional endoscopy and may evade detection on r and om biopsy sample s. OBJECTIVE To demonstrate the capability of endoscopic 3-dimensional optical coherence tomography ( 3D-OCT ) for the identification and characterization of buried gl and s before and after RFA therapy . DESIGN Cross-sectional study . SETTING Single teaching hospital . PATIENTS Twenty-six male and 1 female white patients with BE undergoing RFA treatment . INTERVENTIONS 3D-OCT was performed at the gastroesophageal junction in 18 patients before attaining complete eradication of intestinal metaplasia ( pre-CE-IM group ) and in 16 patients after CE-IM ( post-CE-IM group ) . MAIN OUTCOME MEASUREMENTS Prevalence , size , and location of buried gl and s relative to the squamocolumnar junction . RESULTS 3D-OCT provided an approximately 30 to 60 times larger field of view compared with jumbo and st and ard biopsy and sufficient imaging depth for detecting buried gl and s. Based on 3D-OCT results , buried gl and s were found in 72 % of patients ( 13/18 ) in the pre-CE-IM group and 63 % of patients ( 10/16 ) in the post-CE-IM group . The number ( mean [ st and ard deviation ] ) of buried gl and s per patient in the post-CE-IM group ( 7.1 [ 9.3 ] ) was significantly lower compared with the pre-CE-IM group ( 34.4 [ 44.6 ] ; P = .02 ) . The buried gl and size ( P = .69 ) and distribution ( P = .54 ) were not significantly different before and after CE-IM . LIMITATIONS A single-center , cross-sectional study comparing patients at different time points in treatment . Lack of 1-to-1 coregistered histology for all OCT data sets obtained in vivo . CONCLUSION Buried gl and s were frequently detected with 3D-OCT near the gastroesophageal junction before and after radiofrequency ablation BACKGROUND The optimal management of high- grade dysplasia in patients with Barrett 's esophagus is controversial . The aim of this study was to assess the prevalence of unsuspected carcinoma at esophagectomy in patients with Barrett 's esophagus with high- grade dysplasia after endoscopic surveillance with jumbo biopsy forceps compared with st and ard biopsy forceps . METHODS Twelve patients with high- grade dysplasia in Barrett 's esophagus without gross or microscopic evidence of carcinoma underwent esophagectomy after preoperative endoscopy with 4-quadrant jumbo biopsies at 2-cm intervals .  The findings in this group were compared with those in a group of patients with Barrett 's esophagus who underwent esophagectomy for high- grade dysplasia after biopsies obtained at 2-cm intervals with st and ard biopsy forceps . RESULTS Unsuspected cancer was found in 4 of 12 ( 33 % ) patients in the jumbo biopsy group compared with 6 of 16 ( 38 % ) in the st and ard biopsy group ( p = NS ) . All 6 cancers in the st and ard biopsy group were intramucosal , whereas 2 were intramucosal and 2 were submucosal in the jumbo biopsy group . No patients in either group had lymph node metastases . CONCLUSIONS Unsuspected cancer is found frequently in patients with Barrett 's esophagus who are undergoing esophagectomy for high- grade dysplasia despite the use of a rigorous jumbo biopsy protocol . Esophageal resection is still indicated in appropriately selected patients with high- grade dysplasia until better markers of cancer risk are available BACKGROUND Endoscopic optical coherence tomography ( EOCT ) is a high-resolution , cross-sectional tissue-imaging technique that provides microscopic morphologic information . EOCT should detect dysplasia in Barrett 's epithelium , but this has not been established in a prospect i ve blinded study . This study evaluated the accuracy of EOCT for the diagnosis and the exclusion of dysplasia in patients with Barrett 's esophagus . METHODS A 2.4-mm diameter EOCT probe was modified for use with a cap-fitted , two-channel endoscope . Pairs of EOCT image streams and jumbo biopsy specimens were obtained . Endoscopy/EOCT procedures were performed by 4 endoscopists who separately review ed the EOCT digital images for the absence or the presence of dysplasia ( low grade , high grade , or cancer ) for each biopsy specimen obtained . The endoscopists were blinded to the interpretation of the pathology . An experienced pathologist blinded to the endoscopic/EOCT findings evaluated each biopsy for the absence or the presence of dysplasia . The setting of the study was a major academic medical center . Adult patients with documented Barrett 's esophagus greater than 2 cm were included in the study . The main outcome measurement was the accuracy of EOCT in the detection of dysplasia in  patients with Barrett 's esophagus . RESULTS A total of 314 usable EOCT image stream/biopsy pairs were obtained in 33 patients . By using histology as the st and ard , the performance of EOCT was sensitivity , 68 % ; specificity , 82 % ; positive predictive value , 53 % ; negative predictive value , 89 % ; and diagnostic accuracy , 78 % . Diagnostic accuracy for the 4 endoscopists ranged from 56 % to 98 % . Limitations of the study were the variability in endoscopists ' accuracy rates , difficulty in real-time interpretation , and the need for refined criteria of dysplasia by EOCT imaging . CONCLUSIONS The current EOCT system has an accuracy of 78 % for the detection of dysplasia in patients with Barrett 's esophagus .  EOCT could be used to target biopsies to areas of Barrett 's epithelium with a higher probability for the presence of dysplasia . However , further modifications , including increased resolution and identification of further potential OCT characteristics of dysplasia , are needed before EOCT can be used clinical ly BACKGROUND & AIMS Radiofrequency ablation ( RFA ) can eradicate dysplasia and intestinal metaplasia in patients with dysplastic Barrett 's esophagus ( BE ) , and reduce rates of esophageal adenocarcinoma . We assessed long-term rates of eradication , durability of neosquamous epithelium , disease progression , and safety of RFA in patients with dysplastic BE . METHODS We performed a r and omized trial of 127 subjects with dysplastic BE ; after cross-over subjects were included , 119 received RFA .  Subjects were followed for a mean time of 3.05 years ; the study was extended to 5 years for patients with eradication of intestinal metaplasia at 2 years . Outcomes included eradication of dysplasia or intestinal metaplasia after 2 and 3 years , durability of response , disease progression , and adverse events . RESULTS After 2 years , 101 of 106 patients had complete eradication of all dysplasia ( 95 % ) and 99 of 106 had eradication of intestinal metaplasia ( 93 % ) . After 2 years , among subjects with initial low- grade dysplasia , all dysplasia was eradicated in 51 of 52 ( 98 % ) and intestinal metaplasia was eradicated in 51 of 52 ( 98 % ) ; among subjects with initial high- grade dysplasia , all dysplasia was eradicated in 50 of 54 ( 93 % ) and intestinal metaplasia was eradicated in 48 of 54 ( 89 % ) . After 3 years , dysplasia was eradicated in 55 of 56 of subjects ( 98 % ) and intestinal metaplasia was eradicated in 51 of 56 ( 91 % ) . Kaplan-Meier analysis showed that dysplasia remained eradicated in > 85 % of patients and intestinal metaplasia in > 75 % , without maintenance RFA . Serious adverse events occurred in 4 of 119 subjects ( 3.4 % ) ; the rate of stricture was 7.6 % . The rate of esophageal adenocarcinoma was 1 per 181 patient-years ( 0.55%/patient-years ) ; there was no cancer-related morbidity or mortality . The annual rate of any neoplastic progression was 1 per 73 patient-years ( 1.37%/patient-years ) . CONCLUSIONS In subjects with dysplastic BE , RFA therapy has an acceptable safety profile , is durable , and is associated with a low rate of disease progression , for up to 3 years BACKGROUND AND STUDY AIMS We studied the feasibility of endoscopic optical coherence tomography imaging in esophageal disorders , including Barrett 's esophagus and Barrett-related adenocarcinoma .  Optical coherence tomography is a high-resolution cross-sectional imaging technique with a resolution of almost 10 microm . PATIENTS AND METHODS The mucosal architecture of reflux esophagitis ( n = 9 ) and Barrett 's esophagus ( n = 9 ) including Barrett-related esophageal cancer ( n = 6 ) was studied by optical coherence tomography imaging . RESULTS In different stages of reflux esophagitis edema , fibrinoid deposits , or loss of the epithelial layer were observed . Optical coherence tomography images of Barrett 's esophagus substantially differed from normal esophagus , reflux esophagitis , and esophageal carcinoma . A stratified structure of the mucosa was still preserved in Barrett 's esophagus . However , images of Barrett-related cancer lacked the regular structure of the esophagus . CONCLUSIONS The high consistency of the first optical coherence tomography findings , the resolution of up to 10 microm , and the distinct pattern of normal , inflammatory , premalignant and malignant tissues make optical coherence tomography a promising method for endoscopically obtained optical biopsy BACKGROUND Optical coherence tomography ( OCT ) is a noninvasive technology that can produce high-resolution cross-sectional images in real-time without acoustic coupling , enabling precise assessment of tumor invasion in superficial esophageal squamous cell carcinomas ( SESCCs ) . OBJECTIVE To eluci date the usefulness of in vivo OCT for the staging of SESCCs . DESIGN A single-center , prospect i ve study in 2 phases : phase I to establish the OCT criteria classified into 3 categories ( epithelium or lamina propria mucosa [ EP/LPM ] , muscularis mucosa [ MM ] , submucosa [ SM ] ) and phase II to evaluate these criteria . SETTING An academic medical center . PATIENTS Sixty-two patients with a histological diagnosis of SESCC by routine endoscopy . In the phase I study , 35 images from 16 patients were used . In the phase II study , 109 images from 46 subsequent consecutive patients enrolled from January 2007 to May 2009 were used . INTERVENTIONS We performed OCT for preoperative staging followed by endoscopic submucosal dissection or a surgical procedure and compared precisely the visualized OCT sites with the corresponding tissue sections . MAIN OUTCOME MEASUREMENTS The accuracy of OCT for the staging . RESULTS The overall accuracy rate was 92.7 % ( EP/LPM , 94.9 % ; MM , 85.0 % ; SM , 90.9 % ) . The  OCT signal penetration depth was sufficient to depict the boundary of the deepest region of cancer , the thickness of which was less than 1.5 mm . LIMITATIONS The small number of patients . CONCLUSIONS To our knowledge , this is the first study demonstrating that OCT might be useful for the preoperative staging of SESCCs with a high degree of accuracy BACKGROUND AND AIMS The prevalence and clinical relevance of buried Barrett 's gl and s ( BB ) after radiofrequency ablation ( RFA ) in Barrett 's esophagus ( BE ) are debated . Recent optical coherence tomography studies demonstrated a high prevalence of BBs . Direct histological correlation , however , has been lacking . Volumetric laser endomicroscopy ( VLE ) is a second-generation optical coherence tomography system capable of scanning a large surface of the esophageal wall layers with low-power microscopy resolution . The aim was to evaluate whether post-RFA subsquamous gl and ular structures ( SGSs ) , detected with VLE , actually correspond to BBs by pursuing direct histological correlation with VLE images . METHODS In vivo VLE was performed to detect SGSs in patients with endoscopic regression of BE post-RFA . A second in vivo VLE scan was performed to confirm correct delineation of the SGSs . After endoscopic resection , the specimens were imaged ex vivo with VLE . Extensive histological sectioning of SGS areas was performed , and all histology slides were evaluated by an expert BE pathologist . RESULTS Seventeen patients underwent successful in vivo VLE ( histological diagnosis before endos 
    Output:
    
OCT may identify intestinal metaplasia and dysplasia , but its accuracy may not meet recommended thresholds to replace 4-quadrant biopsies in clinical practice .