Diagnosis of Acute Appendicitis: Low-dose Computed Tomography (CT) Versus Standard-dose CT

Negative Appendectomy Rate Following Low-dose CT vs. Standard-dose CT

The purpose of this study is to determine whether low-dose CT is not inferior to standard-dose CT in the rate of unnecessary appendectomy.

Study Overview

• Status: Completed
• Conditions: Appendicitis
• Intervention / Treatment: Radiation: Diagnostic CT; Radiation: Diagnostic CT

Detailed Description

Acute appendicitis is a very common disease with the lifetime incidence of 7%. Abdomen CT is an established first-line diagnostic test in patients suspected of having acute appendicitis. Since many individuals suspected of having acute appendicitis are young, with a mean age of 30 years, CT radiation is of particular concern.

The estimated lifetime attributable risk of death from cancer due to the radiation exposure of a single abdomen CT study is 2-7/10,000 for average adults ranging 20-40 years in age.

The purpose of this study is to determine whether low-dose CT is not inferior to standard-dose CT in the negative appendectomy rate.

• Study Type: Interventional
• Enrollment (Actual): 891
• Phase: Phase 3

Contacts and Locations

Study Locations

• Korea, Republic of
  • Gyeonggi
    • Seongnam, Gyeonggi, Korea, Republic of, 463-707
      • Seoul National University Bundang Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 15 years to 44 years (Child, Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Suspected of having acute appendicitis
• Referred for abdomen CT from Emergency Department

Exclusion Criteria:

• Body mass index < 18.5 kg/m2 (ultrasonography is favored)
• Intravenous contrast-enhancement is contraindicated

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Low-dose CT	Radiation: Diagnostic CT; 2 mSv in an average patient (Low-dose (1/4 to 1/5 of standard-dose)); Other Names: low-dose CT; Radiation: Diagnostic CT; 8 mSv in an average patient (Standard-dose CT); Other Names: standard-dose CT
Active Comparator: Standard-dose CT	Radiation: Diagnostic CT; 2 mSv in an average patient (Low-dose (1/4 to 1/5 of standard-dose)); Other Names: low-dose CT; Radiation: Diagnostic CT; 8 mSv in an average patient (Standard-dose CT); Other Names: standard-dose CT

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Negative Appendectomy	Number of participants with unnecessary appendectomies (removal of un-inflamed appendix)	1 week after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Additional Imaging Test(s)	Number of participants who need additional imaging test(s) to diagnose or rule out appendicitis	1 week after CT
Appendiceal Perforation	Number of participants with appendiceal perforation	1 week after surgery
Interval Between CT and Appendectomy	Time interval between the CT acquisition and non-incidental appendectomy	1 day after surgery
Interval Between CT and Discharge Without Surgery	Time interval between the CT acquisition and discharge without surgery	3 months after CT
Interval From CT to Discharge After Appendectomy	Time interval between the CT acquisition and discharge after appendectomy	3 months after CT
Likelihood of Appendicitis in CT Report in Patients Confirmed as Having Appendicitis	Grade 1. Definitely absent. Clinical observation is recommended. Grade 2. Probably absent. Clinical observation is recommended. Grade 3. Indeterminate. Clinical observation or surgical exploration is recommended. Grade 4. Probably present. Surgical exploration is recommended. Grade 5. Definitely present. Surgical exploration is recommended. The data is used to calculate sensitivity, specificity, area under receiver-operating-curve and to measure diagnostic confidence.	3 months after CT
Likelihood of Appendicitis in CT Report in Patients Confirmed as Not Having Appendicitis	Grade 1. Definitely absent. Clinical observation is recommended. Grade 2. Probably absent. Clinical observation is recommended. Grade 3. Indeterminate. Clinical observation or surgical exploration is recommended. Grade 4. Probably present. Surgical exploration is recommended. Grade 5. Definitely present. Surgical exploration is recommended. The data are used to calculate sensitivity, specificity, area under receiver-operating-curve and to measure diagnostic confidence.	3 months after CT
Diagnosis of Appendiceal Perforation in CT in Patients With Confirmed Appendicitis.	True positive: Perforation was rated as present in CT report and confirmed as present. False positive: Perforation was rated as present in CT report and confirmed as absent. True negative: Perforation was rated as absent in CT report and confirmed as absent. False negative: Perforation was rated as absent in CT report and confirmed as present. The data are used to calculate sensitivity and specificity.	3 months after CT
Visualization of the Normal Appendix	Grade 0. Not identified Grade 1. Unsure or partly visualized Grade 2. Clearly and entirely visualized	3 months after CT

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Radiation Dose	Radiation dose is measured in terms of dose-length product (mGy•cm) as displayed in the CT console. The "length" indicates the scan range.	1 day after CT
Estimate of Carcinogenic Risk Induced by CT Radiation	Age- and sex-specific carcinogenic risk induced by CT radiation. This is not an actual measurement but an estimate of the stochastic risk, based on assumption and calculation from radiation dose used.	1 day after CT

Collaborators and Investigators

• Sponsor: Seoul National University Bundang Hospital
• Collaborators: GE Healthcare; National Research Foundation of Korea
• Investigators: Principal Investigator: Kyuseok Kim, MD, Seoul National University Bundang Hospital; Principal Investigator: Kyoung Ho Lee, MD, Seoul National University Bundang Hospital

Publications and helpful links

General Publications

• 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.

Study record dates

Study Major Dates

• Study Start: September 1, 2009
• Primary Completion (Actual): April 1, 2011
• Study Completion (Actual): April 1, 2011

Study Registration Dates

• First Submitted: May 15, 2009
• First Submitted That Met QC Criteria: June 3, 2009
• First Posted (Estimate): June 4, 2009

Study Record Updates

• Last Update Posted (Estimate): September 12, 2011
• Last Update Submitted That Met QC Criteria: September 2, 2011
• Last Verified: September 1, 2011

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Digestive System Diseases; Infections; Gastrointestinal Diseases; Gastroenteritis; Intestinal Diseases; Cecal Diseases; Intraabdominal Infections; Appendicitis
• Other Study ID Numbers: SNUBH-LDCTinAPPY