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Is Low Dose Really Low Dose? A Clinical Audit of Low Radiation Dose CT KUB Studies for Suspected Urinary Tract Calculi Chahal, B.S., Kwan, A.L.C, Lambert R.G.W., Nielsen, M.M., Gauvreau, D., Winters, S.D, Olubaniyi, B.O.
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AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

Apr 28, 2018

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Page 1: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

Is Low Dose Really Low Dose?

A Clinical Audit of Low Radiation Dose CT KUB Studies for Suspected Urinary Tract

Calculi

Chahal, B.S., Kwan, A.L.C, Lambert R.G.W., Nielsen, M.M., Gauvreau, D., Winters, S.D, Olubaniyi, B.O.

Page 2: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

•  Chahal, B.S. - None

•  Kwan, A.L.C. - None

•  Lambert, R.G.W. – Consultant for Bioclinica

•  Nielsen, M.M. - None

•  Gauvreau, D. - None

•  Winters, S.D. - Member of the Canadian Armed Forces, Department of National Defence

•  Olubaniyi, B.O - None

Declaration of Conflict of Interest

Page 3: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

The Audit Cycle 1. Identify

the problem

2. Set standards

3. Collect Data

4. Compare results with standards

5. Implement change

6. Conclude or re-audit

Page 4: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

•  Average mean effective dose of 11.2 mSv in 49, 903 scans1

•  “…reduced-dose renal protocol CT is used infrequently…”1

Identify the Problem

1. Lukasiewicz et al. Radiology, 2014 May; 271(2):445-451.

Page 5: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

•  CT KUB gold standard for investigating renal colic2

•  High prevalence requiring repeated studies3

•  Cumulative radiation dose can be high3

Background

Page 6: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

Audit Team Fellow

MD Student

Department Head/Radiologist

Senior CT Technologist

CT Technologist

Body Imaging Radiologist

Quality Assurance Coordinator/Radiologist

Physicist

Page 7: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

TARGET: 80% at ≤ 3 mSv4

We considered:

A. Two targets

B.  3 protocols based on BMI

Not realistic

Set Standards

Page 8: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

Audit Results (1st cycle) 40 studies (from one machine) 3 mSv or less achieved in 6/40 15% [Target: 3 mSv or less in 80%] Target not met

Page 9: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

1. Change Noise Index from 33 to 40

2.  Increase iterative reconstruction blend from 40% to 50% (ASIR)

Implement Change

Page 10: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

Re-Audit Results (2nd cycle)

39 studies 3 mSv or less achieved in 7/39 18% [First cycle was 6/40 15%] [Target: 3 mSv or less in 80%]

Target STILL not met

Page 11: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

1. Change Noise Index: 40 to 50

2. mA: 10 minimum - 300 maximum

3. Scan length: •  “Above the liver to lesser trochanter” •  “1cm above the kidneys to 1 cm below the

pubic symphysis”

Implement Change…Again

Page 12: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

Re-Audit Results (3rd cycle) 37 Studies 3 mSv or less achieved in 15/37 41% [Second cycle: 7/39 18%] [First cycle: 6/40 15%] [Target: 3 mSv or less in 80%] Target STILL not met

Page 13: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

Comparing Cycles

0 2 4 6 8

10 12 14 16 18

First Cycle Second Cycle Third Cycle

Effe

ctiv

e D

ose

(mSv

)

Max Mean Min

Page 14: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

Implementation Issues

1.  Over scanning 2.  Larger patients

Page 15: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

Behavior Change STRATEGY EFFECTIVENESS

Emails *

ý

Word of mouth þ ý

Staff Meeting þ Employee Engagement7,8 þþþ

Page 16: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

Audit Conclusion •  Target not met at first cycle

•  Target not met after first intervention

•  Target not met after second intervention

•  Third intervention performed. Await fourth cycle. •  Further changes?

Page 17: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

Future Direction Kaye Edmonton Clinic

UAH Scanners

Edmonton Hospitals

Page 18: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

1.  Lukasiewicz, AMS., Bhargavan-Chatfield, M., Coombs, L., Ghita, M., Weinreb, J., Gunabushanam, G., Moore, CL. Radiation dose index of renal colic protocol CT studies in the United States: A report from the American College of Radiology National Radiology Data Registry. Radiology, 2014 May; 271(2):445-451.

2.  Yen P, Baerlocher, MO. Five things to know about…Imaging in urolithiasis. CMAJ. 2011 Dec 13;183(18):2133. doi:10.1503/cmaj.101638.

3.  Katz SI, Saluja A, Brink JA, Forman HP. Radiation dose associated with unenhanced CT for suspected renal colic: impact of repetitive studies. AJR Am J Roentgenol. 2006 Apr; 186(4):1120-4.

4.  Niemann T, Kollman T, Bongartz G. Diagnostic performance of low-dose CT for the detection of urolithiasis: a meta-analysis. AJR Am J Roentgenol. 2008 Aug; 191(2):396=401. Doi: 10.2214/AJR.07.3414.

5.  AAPM Report, No. 96. Retrieved from http://www.aapm.org/pubs/reports/RPT_96.pdf

6.  Gervaise A, Naulet O, Beuret F, Henry C, Pernin M,Portron Y, Lapierre-Combes M. Low-dose CT with automatic tube current modulation, adaptive statisical iterative reconstruction, and low tube voltage for the diagnosis of renal colic: impact of body mass index. AJR Am J Roentgenol. 2014 Mar;202(3):553-60. doi: 10.2214/AJR.13.11350.

7.  Scott, TIM., Mannion, R., Davies, HT., Marshall, MN. Implementing culture change in health care: theory and practice. International Journal for Quality in Health Care, 2003; 15(2):111-118.

8.  Davies, H., Powell, A., Rushmer, R. Healthcare professionals’ views on clinician engagement I quality improvement. A literature review. 2007 April. Retrieved from: http://www.health.org.uk/public/cms/75/76/313/534/Healthcare%20professionals%20views%20on%20clinician%20engagement%20in%20quality%20improvement.pdf?realName=W5EHsp.pdf

References

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Acknowledgements: •  Sheara Wilson •  Linda O’Harris, Manager,

Specialty Imaging •  All CT Technologists at UAH

Page 20: AP008 Is Low Dose Really Low Dose Chahal - CAR Lifelong Learning/Meetings/ASM2015...Is Low Dose Really Low Dose? ... 39 studies 3 mSv or less achieved in 7/39 18% ... AAPM Report,

1.  Image quality

2.  Dissemination of recommendations

3.  Educating future technologists about local practice

4.  Preventing overcorrections

Challenges/Limitations