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

Primary Purpose

Appendicitis

Status
Completed
Phase
Not Applicable
Locations
Korea, Republic of
Study Type
Interventional
Intervention
Diagnostic CT with low-dose radiation
Diagnostic CT with standard-dose radiation
Sponsored by
Kyoung Ho Lee, MD
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional diagnostic trial for Appendicitis focused on measuring Appendectomy, Appendicitis, False Positive Reactions, Humans, Radiation Dosage, Tomography, X-Ray Computed, Young Adult

Eligibility Criteria

15 Years - 44 Years (Child, Adult)All SexesDoes not accept healthy volunteers

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

Sites / Locations

  • Kangwon National University Hospital
  • Korea University Ansan Hospital
  • Hallym University Sacred Heart Hospital
  • Soonchunhyang University Bucheon Hospital
  • Wonkwang University Sanbon Hospital
  • Seoul National University Bundang Hospital
  • Daejin Medical Center, Bundang Jesaeng General Hospital
  • Keimyung University Dongsan Medical Center
  • Chonnam National University Hospital
  • Wonkwang University School of Medicine & Hospital
  • Gachon University Gil Medical Center
  • Jeju National University Hospital
  • Seoul National University Hospital
  • Kangbuk Samsung Hospital
  • Severance Hospital
  • The Catholic University of Korea, College of Medicine, Seoul St. Mary's Hospital
  • Soonchunhyang University Seoul Hospital
  • Hallym University Kangnam Sacred Heart Hospital
  • Korea University Guro Hospital
  • Chung-Ang University Hospital

Arms of the Study

Arm 1

Arm 2

Arm Type

Experimental

Active Comparator

Arm Label

Low-dose CT

Standard-dose CT

Arm Description

Diagnostic CT with low-dose radiation

Diagnostic CT with standard-dose radiation

Outcomes

Primary Outcome Measures

Negative Appendectomy Rate
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

Appendiceal Perforation Rate
The percentage of perforated appendicitis among confirmed appendicitis cases.
Number of Appendectomies
Appendectomy rate. The percentage of appendectomies among all randomized cases.
Number of Negative Appendectomies
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.
Prevalence of Perforated Appendicitis
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.
Prevalence of Non-perforated Appendicitis
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.
Need for Additional Imaging Test(s)
The proportion of patients requiring additional imaging test(s) in order to diagnose or rule out appendicitis.
Delay in Patient Disposition
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.
Length of Hospital Stay Associated With Appendectomy
The interval from CT acquisition to hospital discharge after appendectomy.
Diagnostic Performance of CT Reports - AUC
- Area under the receiver-operating-characteristic curve (AUC).
Diagnostic Performance of CT Reports - Sensitivity and Specificity
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.
Diagnostic Confidence in Diagnosing and Ruling Out Appendicitis: Likelihood Score for Appendicitis
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.
Diagnostic Confidence in Diagnosing and Ruling Out Appendicitis: Indeterminate Interpretation (Grade 3)
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.
Diagnostic Confidence in Ruling Out Appendicitis: Normal Appendix Visualization
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.
Diagnosis of Appendiceal Perforation at 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.

Full Information

First Posted
August 15, 2013
Last Updated
August 21, 2018
Sponsor
Kyoung Ho Lee, MD
Collaborators
Ministry of Health & Welfare, Korea, Seoul National University Bundang Hospital, Radiology Imaging Network of Korea for Clinical Research, The LOCAT Group
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1. Study Identification

Unique Protocol Identification Number
NCT01925014
Brief Title
Low vs. Standard Dose CT for Appendicitis Trial
Acronym
LOCAT
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
Study Type
Interventional

2. Study Status

Record Verification Date
August 2018
Overall Recruitment Status
Completed
Study Start Date
December 2013 (Actual)
Primary Completion Date
December 2016 (Actual)
Study Completion Date
February 2017 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor-Investigator
Name of the Sponsor
Kyoung Ho Lee, MD
Collaborators
Ministry of Health & Welfare, Korea, Seoul National University Bundang Hospital, Radiology Imaging Network of Korea for Clinical Research, The LOCAT Group

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
Yes

5. Study Description

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).
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.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Appendicitis
Keywords
Appendectomy, Appendicitis, False Positive Reactions, Humans, Radiation Dosage, Tomography, X-Ray Computed, Young Adult

7. Study Design

Primary Purpose
Diagnostic
Study Phase
Not Applicable
Interventional Study Model
Parallel Assignment
Masking
ParticipantOutcomes Assessor
Allocation
Randomized
Enrollment
3074 (Actual)

8. Arms, Groups, and Interventions

Arm Title
Low-dose CT
Arm Type
Experimental
Arm Description
Diagnostic CT with low-dose radiation
Arm Title
Standard-dose CT
Arm Type
Active Comparator
Arm Description
Diagnostic CT with standard-dose radiation
Intervention Type
Diagnostic Test
Intervention Name(s)
Diagnostic CT with low-dose radiation
Other Intervention Name(s)
Low-dose CT
Intervention Description
Effective dose is aimed at approximately 2 millisievert (mSv) in an average patient.
Intervention Type
Diagnostic Test
Intervention Name(s)
Diagnostic CT with standard-dose radiation
Other Intervention Name(s)
Standard-dose CT
Intervention Description
Effective dose is aimed at approximately 8 millisievert (or less) in an average patient.
Primary Outcome Measure Information:
Title
Negative Appendectomy Rate
Description
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).
Time Frame
1 week after surgery
Secondary Outcome Measure Information:
Title
Appendiceal Perforation Rate
Description
The percentage of perforated appendicitis among confirmed appendicitis cases.
Time Frame
1 week after surgery
Title
Number of Appendectomies
Description
Appendectomy rate. The percentage of appendectomies among all randomized cases.
Time Frame
3 months after CT
Title
Number of Negative Appendectomies
Description
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.
Time Frame
1 week after surgery
Title
Prevalence of Perforated Appendicitis
Description
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.
Time Frame
1 week after surgery
Title
Prevalence of Non-perforated Appendicitis
Description
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.
Time Frame
1 week after surgery
Title
Need for Additional Imaging Test(s)
Description
The proportion of patients requiring additional imaging test(s) in order to diagnose or rule out appendicitis.
Time Frame
1 week after CT
Title
Delay in Patient Disposition
Description
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.
Time Frame
3 months after CT
Title
Length of Hospital Stay Associated With Appendectomy
Description
The interval from CT acquisition to hospital discharge after appendectomy.
Time Frame
3 months after CT
Title
Diagnostic Performance of CT Reports - AUC
Description
- Area under the receiver-operating-characteristic curve (AUC).
Time Frame
3 months after CT
Title
Diagnostic Performance of CT Reports - Sensitivity and Specificity
Description
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.
Time Frame
3 months after CT
Title
Diagnostic Confidence in Diagnosing and Ruling Out Appendicitis: Likelihood Score for Appendicitis
Description
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.
Time Frame
3 months after CT
Title
Diagnostic Confidence in Diagnosing and Ruling Out Appendicitis: Indeterminate Interpretation (Grade 3)
Description
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.
Time Frame
3 months after CT
Title
Diagnostic Confidence in Ruling Out Appendicitis: Normal Appendix Visualization
Description
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.
Time Frame
3 months after CT
Title
Diagnosis of Appendiceal Perforation at CT
Description
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.
Time Frame
3 months after CT

10. Eligibility

Sex
All
Minimum Age & Unit of Time
15 Years
Maximum Age & Unit of Time
44 Years
Accepts Healthy Volunteers
No
Eligibility 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
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Kyoung Ho Lee, MD
Organizational Affiliation
Seoul National University Bundang Hospital
Official's Role
Study Chair
First Name & Middle Initial & Last Name & Degree
Kyuseok Kim, MD
Organizational Affiliation
Seoul National University Bundang Hospital
Official's Role
Study Director
Facility Information:
Facility Name
Kangwon National University Hospital
City
Chuncheon
State/Province
Gangwon
ZIP/Postal Code
200-722
Country
Korea, Republic of
Facility Name
Korea University Ansan Hospital
City
Ansan
State/Province
Gyeonggi
ZIP/Postal Code
425-707
Country
Korea, Republic of
Facility Name
Hallym University Sacred Heart Hospital
City
Anyang
State/Province
Gyeonggi
ZIP/Postal Code
431-070
Country
Korea, Republic of
Facility Name
Soonchunhyang University Bucheon Hospital
City
Bucheon
State/Province
Gyeonggi
ZIP/Postal Code
420-767
Country
Korea, Republic of
Facility Name
Wonkwang University Sanbon Hospital
City
Sanbon
State/Province
Gyeonggi
ZIP/Postal Code
435-040
Country
Korea, Republic of
Facility Name
Seoul National University Bundang Hospital
City
Seongnam
State/Province
Gyeonggi
ZIP/Postal Code
463-707
Country
Korea, Republic of
Facility Name
Daejin Medical Center, Bundang Jesaeng General Hospital
City
Seongnam
State/Province
Gyeonggi
ZIP/Postal Code
463-774
Country
Korea, Republic of
Facility Name
Keimyung University Dongsan Medical Center
City
Daegu
ZIP/Postal Code
700-712
Country
Korea, Republic of
Facility Name
Chonnam National University Hospital
City
Gwangju
ZIP/Postal Code
501-757
Country
Korea, Republic of
Facility Name
Wonkwang University School of Medicine & Hospital
City
Iksan
ZIP/Postal Code
570-711
Country
Korea, Republic of
Facility Name
Gachon University Gil Medical Center
City
Incheon
ZIP/Postal Code
405-760
Country
Korea, Republic of
Facility Name
Jeju National University Hospital
City
Jeju City
ZIP/Postal Code
690-767
Country
Korea, Republic of
Facility Name
Seoul National University Hospital
City
Seoul
ZIP/Postal Code
110-744
Country
Korea, Republic of
Facility Name
Kangbuk Samsung Hospital
City
Seoul
ZIP/Postal Code
110-746
Country
Korea, Republic of
Facility Name
Severance Hospital
City
Seoul
ZIP/Postal Code
120-752
Country
Korea, Republic of
Facility Name
The Catholic University of Korea, College of Medicine, Seoul St. Mary's Hospital
City
Seoul
ZIP/Postal Code
137-701
Country
Korea, Republic of
Facility Name
Soonchunhyang University Seoul Hospital
City
Seoul
ZIP/Postal Code
140-887
Country
Korea, Republic of
Facility Name
Hallym University Kangnam Sacred Heart Hospital
City
Seoul
ZIP/Postal Code
150-950
Country
Korea, Republic of
Facility Name
Korea University Guro Hospital
City
Seoul
ZIP/Postal Code
152-703
Country
Korea, Republic of
Facility Name
Chung-Ang University Hospital
City
Seoul
ZIP/Postal Code
156-755
Country
Korea, Republic of

12. IPD Sharing Statement

Plan to Share IPD
Yes
IPD Sharing 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.
Citations:
PubMed Identifier
22533576
Citation
Kim K, Kim YH, Kim SY, Kim S, Lee YJ, Kim KP, Lee HS, Ahn S, Kim T, Hwang SS, Song KJ, Kang SB, Kim DW, Park SH, Lee KH. Low-dose abdominal CT for evaluating suspected appendicitis. N Engl J Med. 2012 Apr 26;366(17):1596-605. doi: 10.1056/NEJMoa1110734.
Results Reference
background
PubMed Identifier
24438500
Citation
Ahn S; LOCAT group. LOCAT (low-dose computed tomography for appendicitis trial) comparing clinical outcomes following low- vs standard-dose computed tomography as the first-line imaging test in adolescents and young adults with suspected acute appendicitis: study protocol for a randomized controlled trial. Trials. 2014 Jan 17;15:28. doi: 10.1186/1745-6215-15-28.
Results Reference
background
Citation
Ko Y, Choi JW, Kim DH, Lee KJ, Shin SS, Woo JY, Cho SW, Kim BS, Lee KH. Central image archiving and management system for multicenter clinical studies: lessons from low-dose CT for appendicitis trial. J Korean Soc Radiol. 2017 Mar 28;76(3):165-72. doi: 10.3348/jksr.2017.76.3.165.
Results Reference
background
PubMed Identifier
26587949
Citation
Yang HK, Ko Y, Lee MH, Woo H, Ahn S, Kim B, Pickhardt PJ, Kim MS, Park SB, Lee KH; Low-Dose CT for Appendicitis Trial (LOCAT) Group. Initial Performance of Radiologists and Radiology Residents in Interpreting Low-Dose (2-mSv) Appendiceal CT. AJR Am J Roentgenol. 2015 Dec;205(6):W594-611. doi: 10.2214/AJR.15.14513. Erratum In: AJR Am J Roentgenol. 2016 Apr;206(4):901. multiple investigator names added.
Results Reference
background
PubMed Identifier
33825498
Citation
Kim HY, Lee S, Kim DH, Ko Y, Park JH, Ko A, Jeong SM, Park SB, Lee KH; LOCAT Group. Conventional-Dose CT Versus 2-mSv CT for Right Colonic Diverticulitis as an Alternate Diagnosis of Appendicitis: Secondary Analysis of Large Pragmatic Randomized Trial Data. AJR Am J Roentgenol. 2021 Nov;217(5):1113-1121. doi: 10.2214/AJR.21.25584. Epub 2021 Apr 7.
Results Reference
derived
PubMed Identifier
28919126
Citation
LOCAT Group. Low-dose CT for the diagnosis of appendicitis in adolescents and young adults (LOCAT): a pragmatic, multicentre, randomised controlled non-inferiority trial. Lancet Gastroenterol Hepatol. 2017 Nov;2(11):793-804. doi: 10.1016/S2468-1253(17)30247-9. Epub 2017 Sep 12.
Results Reference
derived
Links:
URL
http://www.locat.org/locat_training
Description
LOCAT-Training, a self-learning course to train the radiologists at all Sites to ensure the safety of the participants.

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Low vs. Standard Dose CT for Appendicitis Trial

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