Low vs. Standard Dose CT for Appendicitis Trial (LOCAT)

This study is currently recruiting participants. (see Contacts and Locations)
Verified September 2015 by Seoul National University Bundang Hospital
Ministry of Health & Welfare, Korea
Seoul National University Bundang Hospital
Radiology Imaging Network of Korea for Clinical Research
Information provided by (Responsible Party):
Kyoung Ho Lee, MD, Seoul National University Bundang Hospital
ClinicalTrials.gov Identifier:
First received: August 15, 2013
Last updated: September 19, 2015
Last verified: September 2015
To determine whether low-dose (LD) CT is noninferior to standard-dose (SD) computed tomography (CT) as the first-line imaging test in adolescents and young adults in regard to negative appendectomy rate (NAR).

Condition Intervention
Radiation: Diagnostic CT with low-dose radiation
Radiation: Diagnostic CT with standard-dose radiation

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Outcomes Assessor)
Primary Purpose: Diagnostic
Official Title: A Multi-institutional Trial Comparing Clinical Outcomes Following Low- vs. Standard-dose Abdominal CT as the First-line Imaging Test in Adolescents and Young Adults With Suspected Acute Appendicitis

Resource links provided by NLM:

Further study details as provided by Seoul National University Bundang Hospital:

Primary Outcome Measures:
  • Negative appendectomy rate [ Time Frame: 1 week after surgery ] [ Designated as safety issue: No ]
    Negative appendectomy rate is defined as the percentage of negative (unnecessary) appendectomies out of all non-incidental appendectomies. As a secondary analysis, negative appendectomy rate in an alternative definition is calculated by excluding cases with appendiceal neoplasms without superimposed appendicitis, as appendectomy would be clinically necessary in such patients. Any surgery performed for the treatment of presumed appendicitis is counted as non-incidental appendectomy, even though the surgical procedures may be more extensive than simple appendectomy (e.g., ileocectomy).

Secondary Outcome Measures:
  • Appendiceal perforation rate [ Time Frame: 1 week after surgery ] [ Designated as safety issue: No ]
    The percentage of perforated appendicitis of all confirmed appendicitis cases.

  • Additional Imaging Test(s) [ Time Frame: 1 week after CT ] [ Designated as safety issue: No ]
    The proportion of patients requiring additional imaging test(s) in order to diagnose or rule out appendicitis.

  • Delay in patient disposition [ Time Frame: 1 day after surgery ] [ Designated as safety issue: No ]
    • Interval from CT acquisition to appendectomy in patients undergoing non-incidental appendectomy. Interval appendectomies following percutaneous abscess drainage are not included in this analysis.
    • Interval from CT acquisition to hospital discharge in patients not undergoing surgery.

  • Hospital stay associated with non-incidental appendectomy [ Time Frame: 3 months after CT ] [ Designated as safety issue: No ]
    The interval from CT acquisition to hospital discharge after non-incidental appendectomy.

  • Diagnostic performance of CT reports [ Time Frame: 3 months after CT ] [ Designated as safety issue: No ]
    • Area under receiver-operating-characteristic curve.
    • Diagnostic sensitivity and specificity: for calculation of the sensitivity and specificity, the 5-grade likelihood scores for appendicitis are collapsed into binary responses with a decision threshold of a score ≥ 3 as positive for the diagnosis. This decision threshold is based on the fact that appendicitis is actually present in 13-73% of patients with CT scans interpreted as equivocal and that appendiceal perforation as a consequence of a false-negative diagnosis is considered more harmful to patients than a negative appendectomy as a consequence of a false-positive diagnosis.

  • Diagnostic confidence in diagnosing and ruling out appendicitis [ Time Frame: 3 months after CT ] [ Designated as safety issue: No ]
    • Likelihood score for appendicitis in patients confirmed as having appendicitis.
    • Likelihood score for appendicitis in patients confirmed as not having appendicitis.
    • The frequency of indeterminate CT interpretation (grade 3).
    • The frequency of normal appendix visualization at CT.

  • Diagnosis of appendiceal perforation at CT [ Time Frame: 3 months after CT ] [ Designated as safety issue: No ]
    • Diagnostic sensitivity: the number of correct detections of the perforation divided by the number of cases of perforated appendicitis.
    • Diagnostic specificity: the number of correct ruling out the perforation divided by the number of cases of appendicitis without perforation.

Estimated Enrollment: 3000
Study Start Date: December 2013
Estimated Study Completion Date: July 2016
Estimated Primary Completion Date: April 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Low-dose CT
Diagnostic CT with low-dose radiation
Radiation: Diagnostic CT with low-dose radiation
Effective dose is aimed at approximately 2 millisievert in an average patient.
Other Name: Low-dose CT
Active Comparator: Standard-dose CT
Diagnostic CT with standard-dose radiation
Radiation: Diagnostic CT with standard-dose radiation
Effective dose is aimed at approximately 8 millisievert in an average patient.
Other Name: Standard-dose CT

Detailed Description:
  • Acute appendicitis is a very common disease. Many patients are adolescents or young adults.
  • CT is the current standard imaging test for the diagnosis of appendicitis.
  • In recent years, the awareness of carcinogenic risk associated with CT radiation has increased.
  • According to a recent single-institutional randomized controlled trial, LD CT (employing a quarter of standard radiation dose) was found to be noninferior to SD CT with respect to NARs in adolescents and young adults with suspected appendicitis.
  • However, LD CT is not yet widely accepted.
  • To establish LD CT as the first-line imaging test, a multi-institutional study is needed to confirm the generalizability of the prior single-institutional study.

Ages Eligible for Study:   15 Years to 44 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Emergency department visit with suspected symptoms and signs of acute appendicitis
  • Intravenous contrast-enhanced computed tomography examination requested due to suspicion of appendicitis
  • Willing to provide telephone or cell phone numbers for follow-up
  • Signed informed consent provided prior to study entry

Exclusion Criteria:

  • Prior cross-sectional imaging tests to evaluate the presenting symptoms and signs
  • Prior history of surgical removal of the appendix
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01925014

Contact: Kyoung Ho Lee, MD 82-31-787-7609 kholeemail@gmail.com
Contact: Yousun Ko, MPH 82-31-787-7609 ko.yousun82@gmail.com

Korea, Republic of
Kangwon National University Hospital Recruiting
Chuncheon, Gangwon, Korea, Republic of, 200-722
Contact: Seong Whi Cho, MD       chosw@kangwon.ac.kr   
Principal Investigator: Seong Whi Cho, MD         
Sub-Investigator: Chan Woo Park, MD         
Sub-Investigator: Dae Jin Jung, MD         
Sub-Investigator: Gi Bong Chae, MD         
Sub-Investigator: Jung Yeol Lee, MD         
Sub-Investigator: Taek Guen Ohk, MD         
Sub-Investigator: Yong-Hwan Jeon, MD         
Korea University Ansan Hospital Recruiting
Ansan, Gyeonggi, Korea, Republic of, 425-707
Contact: Han Jin Cho, MD       chohj327@gmail.com   
Principal Investigator: Han Jin Cho, MD         
Sub-Investigator: In Young Choi, MD         
Sub-Investigator: Jong Hak Park, MD         
Sub-Investigator: Jooyeong Kim, MD         
Sub-Investigator: Sang Hoon Cha, MD         
Sub-Investigator: Suk Keu Yeom, MD         
Sub-Investigator: Sung Woo Moon, MD         
Sub-Investigator: Taejin Song, MD         
Sub-Investigator: Young Sik Kim, MD         
Hallym University Sacred Heart Hospital Recruiting
Anyang, Gyeonggi, Korea, Republic of, 431-070
Contact: Min Jeong Kim, MD       drkmj@hallym.or.kr   
Principal Investigator: Min Jeong Kim, MD         
Sub-Investigator: Dong Hoon Kim, MD         
Sub-Investigator: Dong Kyu Kim, RT         
Sub-Investigator: Kyueng Whan Min, MD         
Sub-Investigator: Man Sup Lim, MD         
Sub-Investigator: Sang Ook Ha, MD         
Sub-Investigator: You Dong Sohn, MD         
Sub-Investigator: Young Hwan Lee, MD         
Soonchunhyang University Bucheon Hospital Recruiting
Bucheon, Gyeonggi, Korea, Republic of, 420-767
Contact: Min Hee Lee, MD       hiditter@gmail.com   
Principal Investigator: Min Hee Lee, MD         
Sub-Investigator: Boem Ha Yi, MD         
Sub-Investigator: Eung Jin Shin, MD         
Sub-Investigator: Hae Kyung Lee, MD         
Sub-Investigator: Hee Kyung Kim, MD         
Sub-Investigator: Ho Jung Kim, MD         
Sub-Investigator: Jae Hyung Choi, MD         
Sub-Investigator: Young Soon Cho, MD         
Daejin Medical Center, Bundang Jesaeng General Hospital Recruiting
Seongnam, Gyeonggi, Korea, Republic of, 463-774
Contact: Hyuk Jung Kim, MD       hyukjungk@naver.com   
Principal Investigator: Hyuk Jung Kim, MD         
Sub-Investigator: Byeong Geon Jeon, MD         
Sub-Investigator: Chong Kun Hong, MD         
Sub-Investigator: Kye Won Kwon, MD         
Sub-Investigator: Seok Ki Jang, MD         
Sub-Investigator: Seung Bong Han, RT         
Sub-Investigator: So Ya Paik, MD         
Sub-Investigator: Young Rock Ha, MD         
Sub-Investigator: Young Sik Kim, MD         
Seoul National University Bundang Hospital Recruiting
Seongnam, Gyeonggi, Korea, Republic of, 463-707
Contact: Ji Hoon Park, MD    82317877609    pjihoon79@gmail.com   
Principal Investigator: Ji Hoon Park, MD         
Sub-Investigator: Bon Seung Gu, RT         
Sub-Investigator: Hye Seung Lee, MD         
Sub-Investigator: Jae Hyuk Lee, MD         
Sub-Investigator: Joonghee Kim, MD         
Sub-Investigator: Kyoung Ho Lee, MD         
Sub-Investigator: Kyuseok Kim, MD         
Sub-Investigator: Soyeon Ahn, PhD         
Sub-Investigator: Sung-Bum Kang, MD         
Sub-Investigator: Yoon Jin Lee, MD         
Sub-Investigator: You Hwan Jo, MD         
Sub-Investigator: Young Hoon Kim, MD         
Sub-Investigator: Kwang Pyo Kim, PhD         
Keimyung University Dongsan Medical Center Recruiting
Daegu, Korea, Republic of, 700-712
Contact: Mi Jeong Kim, MD       whp1409@naver.com   
Principal Investigator: Mi Jeong Kim, MD         
Sub-Investigator: Jung Hyeock Kwon, MD         
Sub-Investigator: Seoung Kyu Beak, MD         
Sub-Investigator: Sung Jin Kim, MD         
Sub-Investigator: Woo Ik Choi, MD         
Sub-Investigator: Yu Na Kang, MD         
Chonnam National University Hospital Not yet recruiting
Gwangju, Korea, Republic of, 501-757
Contact: Sang Soo Shin, MD       kjradsss@dreamwiz.com   
Principal Investigator: Sang Soo Shin, MD         
Sub-Investigator: Ho Goon Kim, MD         
Sub-Investigator: Hee Joon Kim, MD         
Sub-Investigator: Jun Hyung Hong, MD         
Sub-Investigator: Kyoung Hwan Song, MD         
Sub-Investigator: Yong Soo Cho, MD         
Sub-Investigator: Yoo Duk Choi, MD         
Wonkwang University Sanbon Hospital Not yet recruiting
Gyeonggi, Korea, Republic of, 435-040
Contact: Nurhee Hong, MD       cher8318@gmail.com   
Principal Investigator: Nurhee Hong, MD         
Wonkwang University School of Medicine & Hospital Recruiting
Iksan, Korea, Republic of, 570-711
Contact: Young Hwan Lee, MD       yjyh@wonkwang.ac.kr   
Principal Investigator: Young-Hwan Lee, MD         
Sub-Investigator: Dong Baek Kang, MD         
Sub-Investigator: Hyun Soo Han, RT         
Sub-Investigator: Jeoung Woo Choi, MD         
Sub-Investigator: Ki-Jung Yoon, MD         
Sub-Investigator: Yong Hwang, MD         
Gachon University Gil Medical Center Recruiting
Incheon, Korea, Republic of, 405-760
Contact: Seung Joon Choi, MD       sjchoi@gilhospital.com   
Principal Investigator: Seung Joon Choi, MD         
Sub-Investigator: Jae-Hyug Woo, MD         
Sub-Investigator: Min-A Lee, MD         
Sub-Investigator: Yong Su Lim, MD         
Sub-Investigator: Young Sup Shim, MD         
Jeju National University Hospital Not yet recruiting
Jeju, Korea, Republic of, 690-767
Contact: Bong Soo Kim, MD       67kbs@medimail.co.kr   
Principal Investigator: Bong Soo Kim, MD         
Sub-Investigator: Chang Lim Hyun, MD         
Sub-Investigator: Guk Myung Choi, MD         
Sub-Investigator: In Ho Jeong, MD         
Sub-Investigator: Kyeong Won Kang, MD         
Sub-Investigator: Seung Hyoung Kim, MD         
Sub-Investigator: Woo Jeong Kim, MD         
Sub-Investigator: Young Joon Kang, MD         
Kangbuk Samsung Hospital Recruiting
Seoul, Korea, Republic of, 110-746
Contact: Mi Sung Kim, MD       misung70@gmail.com   
Principal Investigator: Mi Sung Kim, MD         
Sub-Investigator: Dong Hyuk Shin, MD         
Sub-Investigator: Heon-Ju Kwon, MD         
Sub-Investigator: Pil Cho Choi, MD         
Sub-Investigator: Sang Kuk Han, MD         
Hallym University Kangnam Sacred Heart Hospital Recruiting
Seoul, Korea, Republic of, 150-950
Contact: Ji Young Woo, MD       baccas@empas.com   
Principal Investigator: Ji Young Woo, MD         
Sub-Investigator: Gu Hyun Kang, MD         
Sub-Investigator: Han Myun Kim, MD         
Sub-Investigator: Hyun Young Choi, MD         
Sub-Investigator: Ik Yang, MD         
Sub-Investigator: Jae Ho Jang, RT         
Sub-Investigator: Jeong Won Kim, MD         
Sub-Investigator: Sang Nam Yoon, MD         
Sub-Investigator: Won Hee Kim, MD         
Sub-Investigator: Yong Soo Jang, MD         
The Catholic University of Korea, College of Medicine, Seoul St. Mary's Hospital Recruiting
Seoul, Korea, Republic of, 137-701
Contact: Sung Eun Rha, MD       serha@catholic.ac.kr   
Principal Investigator: Sung Eun Rha, MD         
Sub-Investigator: Dong Kyun Kim, MD         
Sub-Investigator: Eun Sun Jung, MD         
Sub-Investigator: Han Joon Kim, MD         
Sub-Investigator: Ho Kyun Byun, MD         
Sub-Investigator: Han Mo Yoo, MD         
Sub-Investigator: Joon Il Choi, MD         
Sub-Investigator: Jung Sung Kim, MD         
Sub-Investigator: Kyu Nam Park, MD         
Sub-Investigator: Michael Yong Park, MD         
Sub-Investigator: Moon Hyung Choi, MD         
Sub-Investigator: Sang Hoon Oh, MD         
Sub-Investigator: Seo Yeon Youn, MD         
Sub-Investigator: Seung Eun Jung, MD         
Sub-Investigator: Soo Ah Im, MD         
Sub-Investigator: Soo Hyun Kim, MD         
Sub-Investigator: Soon Nam Oh, MD         
Sub-Investigator: Tae Ho Hong, MD         
Sub-Investigator: Won-Kyung Kang, MD         
Sub-Investigator: Young Joon Lee, MD         
Korea University Guro Hospital Recruiting
Seoul, Korea, Republic of, 152-703
Contact: Jongmee Lee, MD       jongmee.lee@gmail.com   
Principal Investigator: Jongmee Lee, MD         
Sub-Investigator: Baek-Hui Kim, MD         
Sub-Investigator: Chang Hee Lee, MD         
Sub-Investigator: Jung Youn Kim, MD         
Sub-Investigator: Sanghee Kang, MD         
Sub-Investigator: Seong Hyeok Choi, MD         
Sub-Investigator: Sung Joon Park, MD         
Sub-Investigator: Yang Shin Park, MD         
Sub-Investigator: Young Duck Cho, MD         
Sub-Investigator: Young Hoon Yoon, MD         
Seoul National University Hospital Not yet recruiting
Seoul, Korea, Republic of, 110-744
Contact: Cheong-Il Shin, MD       cheongil.tree@gmail.com   
Principal Investigator: Cheong-Il Shin, MD         
Sub-Investigator: Dong Ho Lee, MD         
Sub-Investigator: Gyeong Hoon Kang, MD         
Sub-Investigator: Ijin Joo, MD         
Sub-Investigator: Jeong Hee Yoon, MD         
Sub-Investigator: Jeong Ho Park, MD         
Sub-Investigator: Ji Won Park, MD         
Sub-Investigator: Sang Do Shin, MD         
Sub-Investigator: Kyu Joo Park, MD         
Sub-Investigator: Seung-Bum Ryoo, MD         
Sub-Investigator: Seung-Young Jeong, MD         
Sub-Investigator: Su Joa Ahn, MD         
Sub-Investigator: Taehan Kim, MD         
Severance Hospital Recruiting
Seoul, Korea, Republic of, 120-752
Contact: Mi-Suk Park, MD       radpms@yuhs.ac   
Principal Investigator: Mi-Suk Park, MD         
Sub-Investigator: In Cheol Park, MD         
Sub-Investigator: Jae Gil Lee, MD         
Sub-Investigator: Min Joung Kim, MD         
Sub-Investigator: Yong Eun Chung, MD         
Soonchunhyang University Seoul Hospital Recruiting
Seoul, Korea, Republic of, 140-887
Contact: Seong Sook Hong, MD       hongses@schmc.ac.kr   
Principal Investigator: Seong Sook Hong, MD         
Sub-Investigator: Eui Sung Hwang, RT         
Sub-Investigator: Heajin Chung, MD         
Sub-Investigator: Hye Young Jang, MD         
Sub-Investigator: Ji Young Hwang, MD         
Sub-Investigator: Jun Bum Park, MD         
Sub-Investigator: Kyung Yul Hur, MD         
Sub-Investigator: Yoon Mi Jeen, MD         
Sub-Investigator: Young Joo Lee, MD         
Sub-Investigator: Young Shin Cho, MD         
Chung-Ang University Hospital Recruiting
Seoul, Korea, Republic of, 156-755
Contact: Sung Bin Park, MD       pksungbin@paran.com   
Principal Investigator: Sung Bin Park, MD         
Sub-Investigator: Chan Woong Kim, MD         
Sub-Investigator: Dong Hoon Lee, MD         
Sub-Investigator: Seung Eun Lee, MD         
Sub-Investigator: Sung Eun Kim, MD         
Sub-Investigator: Yoo Shin Choi, MD         
Sponsors and Collaborators
Kyoung Ho Lee, MD
Ministry of Health & Welfare, Korea
Seoul National University Bundang Hospital
Radiology Imaging Network of Korea for Clinical Research
Study Chair: Kyoung Ho Lee, MD Seoul National University Bundang Hospital
Study Director: Kyuseok Kim, MD Seoul National University Bundang Hospital
  More Information

Additional Information:
Responsible Party: Kyoung Ho Lee, MD, Professor, Seoul National University Bundang Hospital
ClinicalTrials.gov Identifier: NCT01925014     History of Changes
Other Study ID Numbers: LOCAT
Study First Received: August 15, 2013
Last Updated: September 19, 2015
Health Authority: Korea: Food and Drug Administration

Keywords provided by Seoul National University Bundang Hospital:
False Positive Reactions
Radiation Dosage
Tomography, X-Ray Computed
Young Adult

Additional relevant MeSH terms:
Acute Disease
Cecal Diseases
Digestive System Diseases
Disease Attributes
Gastrointestinal Diseases
Intestinal Diseases
Intraabdominal Infections
Pathologic Processes

ClinicalTrials.gov processed this record on November 25, 2015