This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1111/jgh.14074 This article is protected by copyright. All rights reserved. Ultrasound Surveillance for Cholangiocarcinoma in an Endemic Area Provided Survival Benefits Surachate Siripongsakun 1 , M.D., Sirachat Vidhyarkorn 1 , M.D., Sirivipa Charuswattanakul 1 , M.D., Poemlarp Mekraksakit 1 , M.D., Prakongboon Sungkasubun 2 , M.D., Nuphat Yodkhunnathum 3 , M.D., Sutthirak Tangruangkiat 1 , M.S., Napat Ritlumlert 1 , M.S., Thaniya Sricharunrat 4 , M.D. Sirima Jaroenpatarapesaj 5 , B.N., Kamonwan Soonklang 6 , M.S., Anond Kulthanmanusorn 7 , M.D., Chirayu U Auewarakul 8-9 , M.D., Ph.D., Chulabhorn Mahidol 9-10 , Ph.D. Department of Radiology, Chulabhorn Hospital, Bangkok, Thailand 1 Division of Medical Oncology, Chulabhorn Hospital, Bangkok, Thailand 2 Department of Surgery, Chulabhorn Hospital, Bangkok, Thailand 3 Department of Pathology, Chulabhorn Hospital, Bangkok, Thailand 4 Department of Nursing, Chulabhorn Hospital, Bangkok, Thailand 5 Data Management Unit, HRH Princess Chulabhorn College of Medical Science, Chulabhorn Royal Academy, Bangkok, Thailand 6 Ban Luang Hospital, Nan, Thailand 7 School of Medicine and Public Health, HRH Princess Chulabhorn College of Medical Science, Chulabhorn Royal Academy, Bangkok, Thailand 8 Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand 9 HRH Princess Chulabhorn College of Medical Science, Chulabhorn Royal Academy, Bangkok, Thailand 10