Low vs. Standard Dose CT for Appendicitis Trial

Appendicitis Clinical Trial

— 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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01925014
• Other study ID #: LOCAT
• Status: Completed
• Phase: N/A
• Start date: December 2013
• Est. completion date: February 2017

Study information

• Verified date: August 2018
• Source: Seoul National University Bundang Hospital
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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).

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 3074
• Est. completion date: February 2017
• Est. primary completion date: December 2016
• Accepts healthy volunteers: No
• Gender: All
• Age group: 15 Years to 44 Years

Eligibility

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

Related Conditions & MeSH terms

• Appendicitis

Intervention

Diagnostic Test:
• Diagnostic CT with low-dose radiation
Effective dose is aimed at approximately 2 millisievert (mSv) in an average patient.
• Diagnostic CT with standard-dose radiation
Effective dose is aimed at approximately 8 millisievert (or less) in an average patient.

Locations

Country	Name	City	State
Korea, Republic of	Korea University Ansan Hospital	Ansan	Gyeonggi
Korea, Republic of	Hallym University Sacred Heart Hospital	Anyang	Gyeonggi
Korea, Republic of	Soonchunhyang University Bucheon Hospital	Bucheon	Gyeonggi
Korea, Republic of	Kangwon National University Hospital	Chuncheon	Gangwon
Korea, Republic of	Keimyung University Dongsan Medical Center	Daegu
Korea, Republic of	Chonnam National University Hospital	Gwangju
Korea, Republic of	Wonkwang University School of Medicine & Hospital	Iksan
Korea, Republic of	Gachon University Gil Medical Center	Incheon
Korea, Republic of	Jeju National University Hospital	Jeju City
Korea, Republic of	Wonkwang University Sanbon Hospital	Sanbon	Gyeonggi
Korea, Republic of	Daejin Medical Center, Bundang Jesaeng General Hospital	Seongnam	Gyeonggi
Korea, Republic of	Seoul National University Bundang Hospital	Seongnam	Gyeonggi
Korea, Republic of	Chung-Ang University Hospital	Seoul
Korea, Republic of	Hallym University Kangnam Sacred Heart Hospital	Seoul
Korea, Republic of	Kangbuk Samsung Hospital	Seoul
Korea, Republic of	Korea University Guro Hospital	Seoul
Korea, Republic of	Seoul National University Hospital	Seoul
Korea, Republic of	Severance Hospital	Seoul
Korea, Republic of	Soonchunhyang University Seoul Hospital	Seoul
Korea, Republic of	The Catholic University of Korea, College of Medicine, Seoul St. Mary's Hospital	Seoul

Sponsors (5)

Lead Sponsor	Collaborator
Kyoung Ho Lee, MD	Ministry of Health & Welfare, Korea, Radiology Imaging Network of Korea for Clinical Research, Seoul National University Bundang Hospital, The LOCAT Group

Country where clinical trial is conducted

Korea, Republic of, 

References & Publications (4)

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. — View 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. — View 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.

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. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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).	1 week after surgery
Secondary	Appendiceal Perforation Rate	The percentage of perforated appendicitis among confirmed appendicitis cases.	1 week after surgery
Secondary	Number of Appendectomies	Appendectomy rate. The percentage of appendectomies among all randomized cases.	3 months after CT
Secondary	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.	1 week after surgery
Secondary	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.	1 week after surgery
Secondary	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.	1 week after surgery
Secondary	Need for Additional Imaging Test(s)	The proportion of patients requiring additional imaging test(s) in order to diagnose or rule out appendicitis.	1 week after CT
Secondary	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.	3 months after CT
Secondary	Length of Hospital Stay Associated With Appendectomy	The interval from CT acquisition to hospital discharge after appendectomy.	3 months after CT
Secondary	Diagnostic Performance of CT Reports - AUC	- Area under the receiver-operating-characteristic curve (AUC).	3 months after CT
Secondary	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.	3 months after CT
Secondary	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.	3 months after CT
Secondary	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.	3 months after CT
Secondary	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.	3 months after CT
Secondary	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.	3 months after CT

External Links

•   LOCAT-Training, a self-learning course to train the radiologists at all Sites to ensure the safety of the participants.