CT Dose Simulation Study for Appendicitis

Appendicitis Clinical Trial

Official title:

Optimizing the Radiation Dose for CT Imaging With Iterative Reconstruction in Diagnosing Acute Appendicitis: Dose Simulation Study

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02556983
• Other study ID #: SNUBH-02-2015-030
• Status: Completed
• Phase: N/A
• First received: September 18, 2015
• Last updated: April 11, 2017
• Start date: August 2015
• Est. completion date: March 2017

Study information

• Verified date: April 2017
• Source: Seoul National University Bundang Hospital
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

The study will explore CT radiation dose as low as reasonably achievable in diagnosing acute appendicitis, by using of dose simulation technique and iterative reconstruction.

Description:

Three sequential non-inferiority tests are planned. First, three readers will review the original 2-mSv images. Second, the readers will review the 75%-dose images. After the readers review the 75%-dose images and before the readers reviewed the 50%-dose images, the non-inferiority of 75% dose to the original dose will be tested. If the non-inferiority is not accepted, the study will be terminated with the conclusion of 2 mSv as the lowest acceptable dose. If the non-inferiority is accepted, the study will be continue to the next step. In the same manner, the readers will review the next lower-dose images (50% and then 25%), and then the noninferiority will be tested against the original dose.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 30
• Est. completion date: March 2017
• Est. primary completion date: February 2017
• Accepts healthy volunteers: No
• Gender: All
• Age group: 15 Years to 44 Years

Eligibility

Inclusion Criteria:

• 18-44 years of age.

• Emergency department visit with suspected symptoms and signs of acute appendicitis

• Intravenous contrast-enhanced computed tomography examination requested due to suspicion of appendicitis

Exclusion Criteria:

• having contraindications of intravenous contrast agent

Related Conditions & MeSH terms

• Appendicitis

Intervention

Radiation:
• CT
Contrast-enhanced CT images of the abdomen and pelvis will be obtained during the portal venous phase using a 256-channel CT system (Philips Healthcare, Cleveland, OH). The target median dose-length product (DLP) is 130 mGy·cm, which corresponded to an effective dose of 2 mSv with a conversion factor of 0.015 mSv·mGy-1·cm-1. The radiation output was automatically adjusted according to the individual patient's body size.

Locations

Country	Name	City	State
Korea, Republic of	Seoul National University Bunadang Hospital	Seongnam-Si	Gyeonggi-do

Sponsors (1)

Lead Sponsor	Collaborator
Seoul National University Bundang Hospital

Country where clinical trial is conducted

Korea, Republic of, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Diagnostic performance at original dose (2 mSv) using 5-grade Likert score for the likelihood of appendicitis assigned by each radiologist	The pooled area under curve (AUC) from three radiologists	2 months
Primary	Diagnostic performance at 75% dose (1.5 mSv) using 5-grade Likert score for the likelihood of appendicitis assigned by each radiologist	The pooled AUC from three radiologists	1 months
Primary	Diagnostic performance at 50% dose (1.0 mSv) using 5-grade Likert score for the likelihood of appendicitis assigned by each radiologist	*The analysis of 50%-dose CT images will be performed only if non-inferiority of 75%-dose CT to the original CT is proven in terms of the pooled AUC.; The pooled AUC from three radiologists	8 months
Primary	Diagnostic performance at 25% dose (0.5 mSv) using 5-grade Likert score for the likelihood of appendicitis assigned by each radiologist	*The analysis of 25%-dose CT images will be performed only if non-inferiority of 50%-dose CT is proven to the original CT in terms of the pooled AUC.; The pooled AUC from three radiologists	14 months
Secondary	Sensitivity at original dose (2 mSv) using 5-grade Likert score for the likelihood of appendicitis assigned by each radiologist	For calculation of sensitivity and specificity, the 5-grade scores are collapsed into binary responses with a decision threshold of a score = 3 as positive for the diagnosis.	2 months
Secondary	Specificity at original dose (2 mSv) using 5-grade Likert score for the likelihood of appendicitis assigned by each radiologist	For calculation of sensitivity and specificity, the 5-grade scores are collapsed into binary responses with a decision threshold of a score = 3 as positive for the diagnosis.	2 months
Secondary	Sensitivity at 75% dose (1.5 mSv) using 5-grade Likert score for the likelihood of appendicitis assigned by each radiologist	For calculation of sensitivity and specificity, the 5-grade scores are collapsed into binary responses with a decision threshold of a score = 3 as positive for the diagnosis.	1 month
Secondary	Specificity at 75% dose (1.5 mSv) using 5-grade Likert score for the likelihood of appendicitis assigned by each radiologist	For calculation of sensitivity and specificity, the 5-grade scores are collapsed into binary responses with a decision threshold of a score = 3 as positive for the diagnosis.	1 month
Secondary	Sensitivity at 50% dose (1.0 mSv) using 5-grade Likert score for the likelihood of appendicitis assigned by each radiologist	For calculation of sensitivity and specificity, the 5-grade scores are collapsed into binary responses with a decision threshold of a score = 3 as positive for the diagnosis.	8 months
Secondary	Specificity at 50% dose (1.0 mSv) using 5-grade Likert score for the likelihood of appendicitis assigned by each radiologist	For calculation of sensitivity and specificity, the 5-grade scores are collapsed into binary responses with a decision threshold of a score = 3 as positive for the diagnosis.	8 months
Secondary	Sensitivity at 25% dose (0.5 mSv) using 5-grade Likert score for the likelihood of appendicitis assigned by each radiologist	For calculation of sensitivity and specificity, the 5-grade scores are collapsed into binary responses with a decision threshold of a score = 3 as positive for the diagnosis.	14 months
Secondary	Specificity at 25% dose (0.5 mSv) using 5-grade Likert score for the likelihood of appendicitis assigned by each radiologist	For calculation of sensitivity and specificity, the 5-grade scores are collapsed into binary responses with a decision threshold of a score = 3 as positive for the diagnosis.	14 months
Secondary	Diagnostic confidence in diagnosing and ruling out appendicitis at original CT: the 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	2 months
Secondary	Diagnostic confidence in diagnosing and ruling out appendicitis at 75%-dose CT: the 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	1 month
Secondary	Diagnostic confidence in diagnosing and ruling out appendicitis at 50%-dose CT: the 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	8 month
Secondary	Diagnostic confidence in diagnosing and ruling out appendicitis at 25%-dose CT: the 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	14 month
Secondary	Diagnostic confidence in diagnosing and ruling out appendicitis at original CT: normal appendix visualization rate	The frequency of normal appendix visualization at CT	2 month
Secondary	Diagnostic confidence in diagnosing and ruling out appendicitis at 75%-dose CT: normal appendix visualization rate	The frequency of normal appendix visualization at CT	1 month
Secondary	Diagnostic confidence in diagnosing and ruling out appendicitis at 50%-dose CT: normal appendix visualization rate	The frequency of normal appendix visualization at CT	8 months
Secondary	Diagnostic confidence in diagnosing and ruling out appendicitis at 25%-dose CT: normal appendix visualization rate	The frequency of normal appendix visualization at CT	14 months
Secondary	Diagnostic confidence in diagnosing and ruling out appendicitis at original CT: indeterminate CT interpretation	The frequency of indeterminate CT interpretation (grade 3)	2 months
Secondary	Diagnostic confidence in diagnosing and ruling out appendicitis at 75%-dose CT: indeterminate CT interpretation	The frequency of indeterminate CT interpretation (grade 3)	1 month
Secondary	Diagnostic confidence in diagnosing and ruling out appendicitis at 50%-dose CT: indeterminate CT interpretation	The frequency of indeterminate CT interpretation (grade 3)	8 months
Secondary	Diagnostic confidence in diagnosing and ruling out appendicitis at 25%-dose CT: indeterminate CT interpretation	The frequency of indeterminate CT interpretation (grade 3)	14 months
Secondary	Alternative diagnoses at original CT: the radiologists will record possible alternative diagnosis if the patients are presumed to be not having appendicitis	The numbers of important alternative diagnoses established	2 months
Secondary	Alternative diagnoses at 75%-dose CT: the radiologists will record possible alternative diagnosis if the patients are presumed to be not having appendicitis	The numbers of important alternative diagnoses established	1 month
Secondary	Alternative diagnoses at 50%-dose CT: the radiologists will record possible alternative diagnosis if the patients are presumed to be not having appendicitis	The numbers of important alternative diagnoses established	8 months
Secondary	Alternative diagnoses at 25%-dose CT: the radiologists will record possible alternative diagnosis if the patients are presumed to be not having appendicitis	The numbers of important alternative diagnoses established	14 months