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

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ClinicalTrials.gov Identifier: NCT01925014
Recruitment Status : Completed
First Posted : August 19, 2013
Results First Posted : January 31, 2019
Last Update Posted : January 31, 2019
Sponsor:
Collaborators:
Ministry of Health & Welfare, Korea
Seoul National University Bundang Hospital
Radiology Imaging Network of Korea for Clinical Research
The LOCAT Group
Information provided by (Responsible Party):
Kyoung Ho Lee, MD, Seoul National University Bundang Hospital

Brief Summary:
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 or disease Intervention/treatment Phase
Appendicitis Diagnostic Test: Diagnostic CT with low-dose radiation Diagnostic Test: Diagnostic CT with standard-dose radiation Not Applicable

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.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 3074 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, 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
Actual Study Start Date : December 2013
Actual Primary Completion Date : December 2016
Actual Study Completion Date : February 2017

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Appendicitis

Arm Intervention/treatment
Experimental: Low-dose CT
Diagnostic CT with low-dose radiation
Diagnostic Test: Diagnostic CT with low-dose radiation
Effective dose is aimed at approximately 2 millisievert (mSv) in an average patient.
Other Name: Low-dose CT

Active Comparator: Standard-dose CT
Diagnostic CT with standard-dose radiation
Diagnostic Test: Diagnostic CT with standard-dose radiation
Effective dose is aimed at approximately 8 millisievert (or less) in an average patient.
Other Name: Standard-dose CT




Primary Outcome Measures :
  1. Negative Appendectomy Rate [ Time Frame: 1 week after surgery ]
    Negative appendectomy rate was defined as the percentage of negative (unnecessary) appendectomies among all non-incidental appendectomies. As a secondary analysis, negative appendectomy rate in an alternative definition was 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 was counted as non-incidental appendectomy, even though the surgical procedures were more extensive than simple appendectomy (e.g., ileocectomy).


Secondary Outcome Measures :
  1. Appendiceal Perforation Rate [ Time Frame: 1 week after surgery ]
    The percentage of perforated appendicitis among confirmed appendicitis cases.

  2. Number of Appendectomies [ Time Frame: 3 months after CT ]
    Appendectomy rate. The percentage of appendectomies among all randomized cases.

  3. Number of Negative Appendectomies [ Time Frame: 1 week after surgery ]
    The percentage of negative appendectomies among all randomized cases. In January, 2016, when more than 2000 patients were enrolled, the data and safety monitoring board noted a between-group imbalance in the number of appendectomies. Because of the concern that such an imbalance might potentially jeopardize the comparability for the prespecified endpoints, the study protocol was amended to adopt the following additional secondary endpoints, which were assessed among all randomly assigned patients: the number of appendectomies, number of negative appendectomies, prevalence of perforated appendicitis, and prevalence of non-perforated appendicitis.

  4. Prevalence of Perforated Appendicitis [ Time Frame: 1 week after surgery ]
    The percentage (i.e., prevalence) of perforated appendicitis among all randomized cases. In January, 2016, when more than 2000 patients were enrolled, the data and safety monitoring board noted a between-group imbalance in the number of appendectomies. Because of the concern that such an imbalance might potentially jeopardize the comparability for the prespecified endpoints, the study protocol was amended to adopt the following additional secondary endpoints, which were assessed among all randomly assigned patients: the number of appendectomies, number of negative appendectomies, prevalence of perforated appendicitis, and prevalence of non-perforated appendicitis.

  5. Prevalence of Non-perforated Appendicitis [ Time Frame: 1 week after surgery ]
    The percentage (i.e., prevalence) of non-perforated appendicitis among all randomized cases. In January, 2016, when more than 2000 patients were enrolled, the data and safety monitoring board noted a between-group imbalance in the number of appendectomies. Because of the concern that such an imbalance might potentially jeopardize the comparability for the prespecified endpoints, the study protocol was amended to adopt the following additional secondary endpoints, which were assessed among all randomly assigned patients: the number of appendectomies, number of negative appendectomies, prevalence of perforated appendicitis, and prevalence of non-perforated appendicitis.

  6. Need for Additional Imaging Test(s) [ Time Frame: 1 week after CT ]
    The proportion of patients requiring additional imaging test(s) in order to diagnose or rule out appendicitis.

  7. Delay in Patient Disposition [ Time Frame: 3 months after CT ]
    • The interval from CT acquisition to appendectomy in patients undergoing appendectomy. Interval appendectomies following percutaneous abscess drainage and/or medical treatment were not included in this analysis.
    • The interval from CT acquisition to hospital discharge in patients not undergoing surgery.

  8. Length of Hospital Stay Associated With Appendectomy [ Time Frame: 3 months after CT ]
    The interval from CT acquisition to hospital discharge after appendectomy.

  9. Diagnostic Performance of CT Reports - AUC [ Time Frame: 3 months after CT ]
    - Area under the receiver-operating-characteristic curve (AUC).

  10. Diagnostic Performance of CT Reports - Sensitivity and Specificity [ Time Frame: 3 months after CT ]
    • Diagnostic sensitivity and specificity: the 5-grade likelihood scores for appendicitis were collapsed into binary responses with a decision threshold of a score ≥ 3 as positive for the diagnosis.
    • Sensitivity is a proportion of the positive test among the patient confirmed as having appendicitis.
    • Specificity is a proportion of the negative test among the patient confirmed as not having appendicitis.

  11. Diagnostic Confidence in Diagnosing and Ruling Out Appendicitis: Likelihood Score for Appendicitis [ Time Frame: 3 months after CT ]
    • Likelihood score for appendicitis in patients confirmed as having appendicitis.
    • Likelihood score for appendicitis in patients confirmed as not having appendicitis.

    Grade 1 denotes appendicitis definitely absent; grade 2, appendicitis probably absent; grade 3, indeterminate for the presence of appendicitis; grade 4, appendicitis probably present; and grade 5, appendicitis definitely present.


  12. Diagnostic Confidence in Diagnosing and Ruling Out Appendicitis: Indeterminate Interpretation (Grade 3) [ Time Frame: 3 months after CT ]
    The frequency of indeterminate CT interpretation (grade 3). Grade 1 denotes appendicitis definitely absent; grade 2, appendicitis probably absent; grade 3, indeterminate for the presence of appendicitis; grade 4, appendicitis probably present; and grade 5, appendicitis definitely present.

  13. Diagnostic Confidence in Ruling Out Appendicitis: Normal Appendix Visualization [ Time Frame: 3 months after CT ]
    The frequency of normal appendix visualization at CT. Grade 0 denotes appendix not identified; grade 1, unsure or partly visualized; and grade 2, clearly and entirely visualized.

  14. Diagnosis of Appendiceal Perforation at CT [ Time Frame: 3 months after CT ]
    • 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.



Information from the National Library of Medicine

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Ages Eligible for Study:   15 Years to 44 Years   (Child, Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01925014


Locations
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Korea, Republic of
Kangwon National University Hospital
Chuncheon, Gangwon, Korea, Republic of, 200-722
Korea University Ansan Hospital
Ansan, Gyeonggi, Korea, Republic of, 425-707
Hallym University Sacred Heart Hospital
Anyang, Gyeonggi, Korea, Republic of, 431-070
Soonchunhyang University Bucheon Hospital
Bucheon, Gyeonggi, Korea, Republic of, 420-767
Wonkwang University Sanbon Hospital
Sanbon, Gyeonggi, Korea, Republic of, 435-040
Seoul National University Bundang Hospital
Seongnam, Gyeonggi, Korea, Republic of, 463-707
Daejin Medical Center, Bundang Jesaeng General Hospital
Seongnam, Gyeonggi, Korea, Republic of, 463-774
Keimyung University Dongsan Medical Center
Daegu, Korea, Republic of, 700-712
Chonnam National University Hospital
Gwangju, Korea, Republic of, 501-757
Wonkwang University School of Medicine & Hospital
Iksan, Korea, Republic of, 570-711
Gachon University Gil Medical Center
Incheon, Korea, Republic of, 405-760
Jeju National University Hospital
Jeju City, Korea, Republic of, 690-767
Seoul National University Hospital
Seoul, Korea, Republic of, 110-744
Kangbuk Samsung Hospital
Seoul, Korea, Republic of, 110-746
Severance Hospital
Seoul, Korea, Republic of, 120-752
The Catholic University of Korea, College of Medicine, Seoul St. Mary's Hospital
Seoul, Korea, Republic of, 137-701
Soonchunhyang University Seoul Hospital
Seoul, Korea, Republic of, 140-887
Hallym University Kangnam Sacred Heart Hospital
Seoul, Korea, Republic of, 150-950
Korea University Guro Hospital
Seoul, Korea, Republic of, 152-703
Chung-Ang University Hospital
Seoul, Korea, Republic of, 156-755
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
The LOCAT Group
Investigators
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Study Chair: Kyoung Ho Lee, MD Seoul National University Bundang Hospital
Study Director: Kyuseok Kim, MD Seoul National University Bundang Hospital

Additional Information:
Publications:
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
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Responsible Party: Kyoung Ho Lee, MD, Professor, Seoul National University Bundang Hospital
ClinicalTrials.gov Identifier: NCT01925014     History of Changes
Other Study ID Numbers: LOCAT
First Posted: August 19, 2013    Key Record Dates
Results First Posted: January 31, 2019
Last Update Posted: January 31, 2019
Last Verified: August 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Yes
Plan Description: The LOCAT Group has an active standpoint for sharing the LOCAT data, which is in line with the proposal from the International Committee of Medical Journal Editors. The LOCAT Group will share de-identified individual-participant data underlying the main LOCAT results no later than 6 months after the publication of the results. The data will be kept in a publicly available website and freely available to anyone upon request.

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Kyoung Ho Lee, MD, Seoul National University Bundang Hospital:
Appendectomy
Appendicitis
False Positive Reactions
Humans
Radiation Dosage
Tomography, X-Ray Computed
Young Adult
Additional relevant MeSH terms:
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Appendicitis
Intraabdominal Infections
Infection
Gastroenteritis
Gastrointestinal Diseases
Digestive System Diseases
Cecal Diseases
Intestinal Diseases