Comparison of Tissue Architectural Changes between Radiofrequency Ablation and Cryospray Ablation in Barrett’s Esophagus Using Endoscopic Three-Dimensional Optical Coherence Tomography

Gastroenterology Research and Practice, Jul 2012

Two main nonsurgical endoscopic approaches for ablating dysplastic and early cancer lesions in the esophagus have gained popularity, namely, radiofrequency ablation (RFA) and cryospray ablation (CSA). We report a uniquely suited endoscopic and near-microscopic imaging modality, three-dimensional (3D) optical coherence tomography (OCT), to assess and compare the esophagus immediately after RFA and CSA. The maximum depths of architectural changes were measured and compared between the two treatment groups. RFA was observed to induce 230~260 μm depth of architectural changes after each set of ablations over a particular region, while CSA was observed to induce edema-like spongiform changes to ~640 μm depth within the ablated field. The ability to obtain micron-scale depth-resolved images of tissue structural changes following different ablation therapies makes 3D-OCT an ideal tool to assess treatment efficacy. Such information could be potentially used to provide real-time feedback for treatment dosing and to identify regions that need further retreatment.

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Comparison of Tissue Architectural Changes between Radiofrequency Ablation and Cryospray Ablation in Barrett’s Esophagus Using Endoscopic Three-Dimensional Optical Coherence Tomography

Comparison of Tissue Architectural Changes between Radiofrequency Ablation and Cryospray Ablation in Barrett’s Esophagus Using Endoscopic Three-Dimensional Optical Coherence Tomography Tsung-Han Tsai,1 Chao Zhou,1 Hsiang-Chieh Lee,1 Yuankai K. Tao,1 Osman O. Ahsen,1 Marisa Figueiredo,2,3 Desmond C. Adler,4 Joseph M. Schmitt,4 Qin Huang,2,3 James G. Fujimoto,1 and Hiroshi Mashimo2,3 1Department of Electrical Engineering and Computer Science, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA 2Gastroenterology Section, VA Boston Healthcare System, Boston, MA 02130, USA 3Harvard Medical School, Boston, MA 02115, USA 4LightLab Imaging Inc.-St. Jude Medical Inc., Westford, MA 01886, USA Received 10 March 2012; Revised 8 May 2012; Accepted 8 May 2012 Academic Editor: Mohammad Ahmad Al-Shatouri Copyright © 2012 Tsung-Han Tsai et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Two main nonsurgical endoscopic approaches for ablating dysplastic and early cancer lesions in the esophagus have gained popularity, namely, radiofrequency ablation (RFA) and cryospray ablation (CSA). We report a uniquely suited endoscopic and near-microscopic imaging modality, three-dimensional (3D) optical coherence tomography (OCT), to assess and compare the esophagus immediately after RFA and CSA. The maximum depths of architectural changes were measured and compared between the two treatment groups. RFA was observed to induce 230~260  m depth of architectural changes after each set of ablations over a particular region, while CSA was observed to induce edema-like spongiform changes to ~640  m depth within the ablated field. The ability to obtain micron-scale depth-resolved images of tissue structural changes following different ablation therapies makes 3D-OCT an ideal tool to assess treatment efficacy. Such information could be potentially used to provide real-time feedback for treatment dosing and to identify regions that need further retreatment. 1. Introduction Radiofrequency ablation (RFA) and cryospray ablation (CSA) are recently developed methods that utilize thermal gradients to treat dysplastic and early cancer lesions of the esophagus, such as those arising in the setting of Barrett’s esophagus (BE). Both therapeutic technologies allow broad and superficial treatment fields for BE [1–8]. Recent clinical trials using RFA treatment have shown that complete eradication of dysplasia (CE-D) was achieved in 98% and 93% of patients with low-grade dysplasia (LGD) and high-grade dysplasia (HGD) at two-year followup [9]. Complete eradication of intestinal metaplasia (CE-IM) was achieved in 92% of patients with nondysplastic BE (NDBE) at up to 5 years of followup [10]. CSA is a newer therapeutic technology, so fewer large-scale clinical trials have been conducted. However, several pilot studies have shown that CSA is highly effective in eradicating HGD [6–8]. Complete eradication of the HGD, CE-D, and CE-IM in 94%, 88%, and 53% of BE patients was reported in a multicenter study [8]. Another multicenter study also reported 97%, 87%, and 57% complete eradication of HGD, CE-D, and CE-IM at 10.5 months of followup [7]. Although these studies indicate that both therapeutic technologies allow broad and superficial treatment fields for BE, repeated RFA/CSA treatments were generally required to achieve complete treatment response. On average, CE-IM was achieved after over 3.4 sessions using RFA [4, 9, 10] and 4.2 sessions using CSA [8, 11] for patients with BE. Considering the recovery time between consecutive therapeutic procedures (6–8 weeks for RFA treatment and 4–6 weeks for CSA treatment), the overall treatment process to achieve CE-IM can be over a year long [7–10, 12, 13]. Multiple repeated esophagogastroduodenoscopy (EGD) and therapeutic procedures also increase costs to the healthcare system [14–16]. Thus, methods to improve the efficacy of each therapeutic procedure would reduce the total number of treatment sessions, reduce patient anxiety, and improve the benefit from these endoscopic therapeutic techniques. Optical coherence tomography (OCT) is a volumetric imaging technique that generates cross-sectional images of internal structure with micrometer resolutions and millimeter imaging depth by measuring the echo time delays of backscattered light [17]. Endoscopic OCT techniques have been developed to image the human gastrointestinal (GI) tract with over 1 mm imaging depth [18–27] and were extensively used in esophagus to evaluate specialized intestinal metaplasia, dysplasia, and adenocarcinoma with high sensitivity and specificity to differentiate different pathologies [23, 28]. Recently, with the dramatic increases of imaging speed, endoscopic 3D-OCT has become possible and provides a powerful (...truncated)


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Tsung-Han Tsai, Chao Zhou, Hsiang-Chieh Lee, Yuankai K. Tao, Osman O. Ahsen, Marisa Figueiredo, Desmond C. Adler, Joseph M. Schmitt, Qin Huang, James G. Fujimoto, Hiroshi Mashimo. Comparison of Tissue Architectural Changes between Radiofrequency Ablation and Cryospray Ablation in Barrett’s Esophagus Using Endoscopic Three-Dimensional Optical Coherence Tomography, Gastroenterology Research and Practice, 2012, 2012, DOI: 10.1155/2012/684832