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Tu1964 Feasibility of Using a Novel Imaging Technique in Patients With Barrett's Esophagus: 3 Dimensional Volumetric Laser Endomicroscopy
AGA Abstracts
three tertiary care centers. Demographic data, indication for the procedure, endoscopic information, procedure time, adverse events and final histological diagnosis were recorded. The primary aim of the study was to assess the feasibility and safety of the VLE procedure. Results: A total of 74 patients were recruited: 67 male and 7 female. The mean age of the cohort was 67.2 (95%CI, 65-69.4) years; all Caucasians. The mean Prague C and M extents were 2.5 and 3.5 cms respectively. The indications for the VLE procedure was: 27 (36.5%) BE surveillance, 2 screening for suspected BE, 14 prior to endoscopic mucosal resection (EMR), 13 post radiofrequency ablation (RFA) and 6 prior to RFA. The VLE procedure was successfully performed in all patients and no serious adverse events (bleeding, perforation) were noted (1 patient with superficial mucosal tear at GEJ). The average time for endoscopy was 38.6 (95% CI, 34.8-42.5) minutes and the average time for VLE was 17 (14.6-19.5) minutes. In a blinded fashion, 25 VLE imaging scans were reviewed by a gastroenterologist experienced in VLE; preliminary results indicated that all 4 patients with HGD/early cancer were detected by VLE. Conclusions: Results of this large, multi-center study using a novel imaging technique indicate that VLE is a safe procedure that can be performed in patients with Barrett's esophagus. Real time 3 dimensional images provided by this modality enable the endoscopist to visualize the mucosa and sub-mucosa. Further studies are needed to evaluate the clinical utility of VLE.
Tu1963 Contrast Enhancement for Three-Dimensional Optical Coherence Tomography Images for Improved Delineation of Subsurface Structures Osman O. Ahsen, Michael G. Giacomelli, Tsung-Han Tsai, Yuankai K. Tao, Hsiang-Chieh Lee, Kaicheng Liang, Chao Zhou, Marisa Figueiredo, Desmond C. Adler, Joseph M. Schmitt, Qin Huang, James G. Fujimoto, Hiroshi Mashimo BACKGROUND/AIMS: Three-dimensional endomicroscopy using optical coherence tomography (3D-OCT) provides cross sectional and volumetric images of tissue microstructure without requiring extrinsic contrast agents. We recently described "buried" Barrett's esophagus (BE) glands and ability to predict the efficacy of radio frequency ablation (RFA) using this uniquely suited imaging modality. In this study, we demonstrate a processing method that provides enhanced contrast to 3D-OCT images by analysing the variations in the intensity profile of the structural images. The processed 3D-OCT images improve the identification and classification of subsurface tissue architectures. METHODS: The study was performed at the VA Boston Healthcare System (VABHS) with the study protocol approved by the VABHS, Harvard Medical School and M.I.T. The analysis method calculates the normalized gradient of the local intensity profile of 3D-OCT images and overlays the processing result onto the original intensity image in a Hue-Saturation-Value (HSV) color space. Images acquired from upper esophagus of normal and BE patients undergoing endoscopic surveillance are analysed with the new processing method. RESULTS: 3D-OCT intensity images (Fig. 1(A, C), and the overlay images derived from the intensity analysis (Fig. 1(B, D)) from endoscopically normal-appearing (A and B) and Barrett's (C and D) esophagus demonstrate the ability of the new analysis method to enhance the contrast of the 3D-OCT images. Consistent with characteristic features of normal esophagus, intensity image in Fig. 1(A) shows squamous epithelium (SE) and lamina propria/muscularis mucosa (LP/MM) layers. These two layers are better delineated in the enhanced HSV image shown in Fig. 1(B), where the SE layer appears with the tones blue and the LP/MM layers appears with the tones of green and red. Application of this method for 3D-OCT images taken from the BE patient showed disruption of this layered architecture (Fig. 1(D)). Moreover, images taken from BE patients immediately after RFA showed enhanced contrast for the residual burned tissue and the underlying subsurface structures, showing that the enhanced contrast might also be useful in assessing RFA treatment response and efficacy. CONCLUSIONS: This study demonstrates that by analysing the variations of the local intensity profile it is possible to enhance the contrast of conventional 3D-OCT images without the use of extrinsic contrast agents. The application of this method should aid the identification of fine subsurface structures and possibly improve the diagnostic capability of the 3D-OCT. ACKNOWLEDGEMENT: NIH 5R01-CA075289-14, K99-EB010071-01A1, AFOSR FA9550-07-1-0101, and FA9550-10-1-0551.
Tu1965 Polarization Gating Spectroscopy to Detect Pancreas Cancer - Final Results of the Pilot Study Mihir K. Patel, Andrew Gomes, Darla J. Hardee, Sergio M. Crespo, Mohamed O. Othman, Massimo Raimondo, Timothy A. Woodward, Hemant K. Roy, Vadim Backman, Michael B. Wallace Background: Pancreatic cancer usually requires invasive fine needle aspiration or biopsy via endoscopic or percutaneous modalities to confirm the diagnosis. Field effect theory is a concept that cancers arise in a broad field of abnormal tissue which may facilitate remote detection of the "field" abnormality. Microvasculature changes such as angiogenesis in the tissue surrounding the neoplastic lesions can potentially identify the neoplastic lesions from a distance in less invasive manner. Polarization gating spectroscopy can quantify the changes in the microvasculature such as deoxyhemoglobin concentration (DHB) and the average blood vessel radius (BVR). We have developed a through-the endoscope fiberoptic probe to obtain these measurements. Aim: To determine the feasibility and efficacy of polarization gating spectroscopy to identify patients with pancreatic cancer with the help of field effect theory. Methods: Prospectively, adult (≥ 18 yrs) patients undergoing upper EUS with EGD at our institution were screened. The patients with known pancreatic cyst, premalignant gastro-pancreatic-duodenal lesions etc. were excluded. The patients confirmed to have pancreatic cancer during EUS-FNA were included in the "Cancer" group. The patients without pancreatic lesion were included in the "Control" group. We planned to recruit 15 patients in each group. We obtained spectroscopic measurements of DHB and BVR with fiberoptic probe from 5 peri-ampullary locations (ampulla, just proximal and distal from the ampulla, 1cm proximal and distal from the ampulla). We used Wilcoxon Rank Sum test for the statistical analysis (p≤0.05). Results: We recruited 15 patients in "cancer" group and 15 patients in the "control" group. The mean age in cancer patients was 73 yrs (73% male) and in control patients was 63 yrs (60% male). Among 5 peri-ampullary locations, the DHB and BVR readings at the ampulla showed maximum ability to differentiate cancer from control. At the ampullary site, the increasing DHB (p=0.0002) and BVR (p=0.013) were statistically significant in patients with pancreatic cancer against controls (see figure). The DHB and BVR alone or in combination showed high sensitivity and specificity in differentiating pancreatic cancer from control (see table). Age and gender did not have statistically significant effect on DHB and BVR readings in cancer or control patients. Conclusion: The spectroscopic measurements of the DHB and BVR by fiberoptic probe are feasible. Such measurements at ampullary site can differentiate patients with pancreas cancer from patients without pancreas cancer with high sensitivity and specificity. This novel method can be potentially helpful to diagnose the pancreatic cancer from a distance in less invasive manner than current techniques. The sensitivity and specificity of DHB and BVR at the ampulla in differentiating pancreatic cancer versus control
Figure 1: 3D-OCT intensity images (Fig. 1(A, C), and the overlay images derived from the intensity analysis (Fig. 1(B, D)) from endoscopically normal-appearing (A and B) and Barrett's (C and D) esophagus. SE: Squamous epithelium, LP/MM: Lamina propria/ Muscularis mucosa, BE: Barrett's Esophagus. Tu1964
DHB- deoxyhemoglobin concentration, BVR- Average blood vessel radius, ROC-Receiving operator curve
Feasibility of Using a Novel Imaging Technique in Patients With Barrett's Esophagus: 3 Dimensional Volumetric Laser Endomicroscopy Prateek Sharma, Vijay Kanakadandi, Kenneth K. Wang, Guillermo J. Tearney, Maria Giacchino, Michael B. Wallace, Herbert C. Wolfsen Background: Endoscopic surveillance is recommended in patients with Barrett's esophagus (BE), including in those after successful endoscopic eradication therapy. However, endoscopic surveillance with random biopsies is limited because HGD/early cancer cannot be visualized endoscopically, a small fraction of the entire esophageal surface is sampled and sub-squamous glands can be missed (post ablation patients). Volumetric laser endomicroscopy (VLE) is an imaging modality, which provides real time 3 dimensional images of mucosa and submucosa of the esophagus. Aim: To study the feasibility and safety of VLE imaging in BE patients. Methods: Imaging: For this prospective, multi-center study, the NvisionVLE™ Imaging System (NinePoint Medical Inc.,Cambridge, MA) was used. The system utilizes a next-generation form of optical coherence tomography (OCT), which is similar to ultrasound, using near-infrared light rather than sound to image the esophagus. High resolution images are collected real-time, using an optical probe which rotates and pulls back for 6cm, imaging to a depth of 3mm into the mucosa and submucosa. The probe is captive within a 25 mm, through-the-scope, low pressure balloon catheter.Patients: BE patients were recruited from
AGA Abstracts
Scatterplot of DHB and average BVR measurements at the ampulla.
S-892
three tertiary care centers. Demographic data, indication for the procedure, endoscopic information, procedure time, adverse events and final histological diagnosis were recorded. The primary aim of the study was to assess the feasibility and safety of the VLE procedure. Results: A total of 74 patients were recruited: 67 male and 7 female. The mean age of the cohort was 67.2 (95%CI, 65-69.4) years; all Caucasians. The mean Prague C and M extents were 2.5 and 3.5 cms respectively. The indications for the VLE procedure was: 27 (36.5%) BE surveillance, 2 screening for suspected BE, 14 prior to endoscopic mucosal resection (EMR), 13 post radiofrequency ablation (RFA) and 6 prior to RFA. The VLE procedure was successfully performed in all patients and no serious adverse events (bleeding, perforation) were noted (1 patient with superficial mucosal tear at GEJ). The average time for endoscopy was 38.6 (95% CI, 34.8-42.5) minutes and the average time for VLE was 17 (14.6-19.5) minutes. In a blinded fashion, 25 VLE imaging scans were reviewed by a gastroenterologist experienced in VLE; preliminary results indicated that all 4 patients with HGD/early cancer were detected by VLE. Conclusions: Results of this large, multi-center study using a novel imaging technique indicate that VLE is a safe procedure that can be performed in patients with Barrett's esophagus. Real time 3 dimensional images provided by this modality enable the endoscopist to visualize the mucosa and sub-mucosa. Further studies are needed to evaluate the clinical utility of VLE.
Tu1963 Contrast Enhancement for Three-Dimensional Optical Coherence Tomography Images for Improved Delineation of Subsurface Structures Osman O. Ahsen, Michael G. Giacomelli, Tsung-Han Tsai, Yuankai K. Tao, Hsiang-Chieh Lee, Kaicheng Liang, Chao Zhou, Marisa Figueiredo, Desmond C. Adler, Joseph M. Schmitt, Qin Huang, James G. Fujimoto, Hiroshi Mashimo BACKGROUND/AIMS: Three-dimensional endomicroscopy using optical coherence tomography (3D-OCT) provides cross sectional and volumetric images of tissue microstructure without requiring extrinsic contrast agents. We recently described "buried" Barrett's esophagus (BE) glands and ability to predict the efficacy of radio frequency ablation (RFA) using this uniquely suited imaging modality. In this study, we demonstrate a processing method that provides enhanced contrast to 3D-OCT images by analysing the variations in the intensity profile of the structural images. The processed 3D-OCT images improve the identification and classification of subsurface tissue architectures. METHODS: The study was performed at the VA Boston Healthcare System (VABHS) with the study protocol approved by the VABHS, Harvard Medical School and M.I.T. The analysis method calculates the normalized gradient of the local intensity profile of 3D-OCT images and overlays the processing result onto the original intensity image in a Hue-Saturation-Value (HSV) color space. Images acquired from upper esophagus of normal and BE patients undergoing endoscopic surveillance are analysed with the new processing method. RESULTS: 3D-OCT intensity images (Fig. 1(A, C), and the overlay images derived from the intensity analysis (Fig. 1(B, D)) from endoscopically normal-appearing (A and B) and Barrett's (C and D) esophagus demonstrate the ability of the new analysis method to enhance the contrast of the 3D-OCT images. Consistent with characteristic features of normal esophagus, intensity image in Fig. 1(A) shows squamous epithelium (SE) and lamina propria/muscularis mucosa (LP/MM) layers. These two layers are better delineated in the enhanced HSV image shown in Fig. 1(B), where the SE layer appears with the tones blue and the LP/MM layers appears with the tones of green and red. Application of this method for 3D-OCT images taken from the BE patient showed disruption of this layered architecture (Fig. 1(D)). Moreover, images taken from BE patients immediately after RFA showed enhanced contrast for the residual burned tissue and the underlying subsurface structures, showing that the enhanced contrast might also be useful in assessing RFA treatment response and efficacy. CONCLUSIONS: This study demonstrates that by analysing the variations of the local intensity profile it is possible to enhance the contrast of conventional 3D-OCT images without the use of extrinsic contrast agents. The application of this method should aid the identification of fine subsurface structures and possibly improve the diagnostic capability of the 3D-OCT. ACKNOWLEDGEMENT: NIH 5R01-CA075289-14, K99-EB010071-01A1, AFOSR FA9550-07-1-0101, and FA9550-10-1-0551.
Tu1965 Polarization Gating Spectroscopy to Detect Pancreas Cancer - Final Results of the Pilot Study Mihir K. Patel, Andrew Gomes, Darla J. Hardee, Sergio M. Crespo, Mohamed O. Othman, Massimo Raimondo, Timothy A. Woodward, Hemant K. Roy, Vadim Backman, Michael B. Wallace Background: Pancreatic cancer usually requires invasive fine needle aspiration or biopsy via endoscopic or percutaneous modalities to confirm the diagnosis. Field effect theory is a concept that cancers arise in a broad field of abnormal tissue which may facilitate remote detection of the "field" abnormality. Microvasculature changes such as angiogenesis in the tissue surrounding the neoplastic lesions can potentially identify the neoplastic lesions from a distance in less invasive manner. Polarization gating spectroscopy can quantify the changes in the microvasculature such as deoxyhemoglobin concentration (DHB) and the average blood vessel radius (BVR). We have developed a through-the endoscope fiberoptic probe to obtain these measurements. Aim: To determine the feasibility and efficacy of polarization gating spectroscopy to identify patients with pancreatic cancer with the help of field effect theory. Methods: Prospectively, adult (≥ 18 yrs) patients undergoing upper EUS with EGD at our institution were screened. The patients with known pancreatic cyst, premalignant gastro-pancreatic-duodenal lesions etc. were excluded. The patients confirmed to have pancreatic cancer during EUS-FNA were included in the "Cancer" group. The patients without pancreatic lesion were included in the "Control" group. We planned to recruit 15 patients in each group. We obtained spectroscopic measurements of DHB and BVR with fiberoptic probe from 5 peri-ampullary locations (ampulla, just proximal and distal from the ampulla, 1cm proximal and distal from the ampulla). We used Wilcoxon Rank Sum test for the statistical analysis (p≤0.05). Results: We recruited 15 patients in "cancer" group and 15 patients in the "control" group. The mean age in cancer patients was 73 yrs (73% male) and in control patients was 63 yrs (60% male). Among 5 peri-ampullary locations, the DHB and BVR readings at the ampulla showed maximum ability to differentiate cancer from control. At the ampullary site, the increasing DHB (p=0.0002) and BVR (p=0.013) were statistically significant in patients with pancreatic cancer against controls (see figure). The DHB and BVR alone or in combination showed high sensitivity and specificity in differentiating pancreatic cancer from control (see table). Age and gender did not have statistically significant effect on DHB and BVR readings in cancer or control patients. Conclusion: The spectroscopic measurements of the DHB and BVR by fiberoptic probe are feasible. Such measurements at ampullary site can differentiate patients with pancreas cancer from patients without pancreas cancer with high sensitivity and specificity. This novel method can be potentially helpful to diagnose the pancreatic cancer from a distance in less invasive manner than current techniques. The sensitivity and specificity of DHB and BVR at the ampulla in differentiating pancreatic cancer versus control
Figure 1: 3D-OCT intensity images (Fig. 1(A, C), and the overlay images derived from the intensity analysis (Fig. 1(B, D)) from endoscopically normal-appearing (A and B) and Barrett's (C and D) esophagus. SE: Squamous epithelium, LP/MM: Lamina propria/ Muscularis mucosa, BE: Barrett's Esophagus. Tu1964
DHB- deoxyhemoglobin concentration, BVR- Average blood vessel radius, ROC-Receiving operator curve
Feasibility of Using a Novel Imaging Technique in Patients With Barrett's Esophagus: 3 Dimensional Volumetric Laser Endomicroscopy Prateek Sharma, Vijay Kanakadandi, Kenneth K. Wang, Guillermo J. Tearney, Maria Giacchino, Michael B. Wallace, Herbert C. Wolfsen Background: Endoscopic surveillance is recommended in patients with Barrett's esophagus (BE), including in those after successful endoscopic eradication therapy. However, endoscopic surveillance with random biopsies is limited because HGD/early cancer cannot be visualized endoscopically, a small fraction of the entire esophageal surface is sampled and sub-squamous glands can be missed (post ablation patients). Volumetric laser endomicroscopy (VLE) is an imaging modality, which provides real time 3 dimensional images of mucosa and submucosa of the esophagus. Aim: To study the feasibility and safety of VLE imaging in BE patients. Methods: Imaging: For this prospective, multi-center study, the NvisionVLE™ Imaging System (NinePoint Medical Inc.,Cambridge, MA) was used. The system utilizes a next-generation form of optical coherence tomography (OCT), which is similar to ultrasound, using near-infrared light rather than sound to image the esophagus. High resolution images are collected real-time, using an optical probe which rotates and pulls back for 6cm, imaging to a depth of 3mm into the mucosa and submucosa. The probe is captive within a 25 mm, through-the-scope, low pressure balloon catheter.Patients: BE patients were recruited from
AGA Abstracts
Scatterplot of DHB and average BVR measurements at the ampulla.
S-892