1. Monitoring Radiation Exposure: Standards, Tools and IHE REM ICIA33
Presenters: Dr. Michael McNitt-Gray – UCLA
Kevin O’Donnell – Toshiba
Dr. Tessa Cook – U Penn
Michael F. McNitt-Gray, PhD, DABR, FAAPM Professor, Department of Radiology
Director, Biomedical Physics Graduate Program
David Geffen School of Medicine at UCLA

2. Outline Physics Perspective CT Dose Definitions & Metrics– MMG
IT Perspective Standards & Tools – KO
Radiologist Perspective Deployment & Practice - TC

3. Disclosures
Kevin O’Donnell :
Employee, Toshiba Corporation  

4. “The future is already here; it’s just not evenly distributed yet.”
Where’s My Flying Car?
“The future is already here; it’s just not evenly distributed yet.”
OK, Dose tracking isn’t as much fun as a flying car, but the point is that the tools are available off the shelf today.
If you think you should be doing something, there is no excuse not to.
Get started.

5. Dose Tracking in Products
IHE Radiation Exposure Monitoring
32 vendors already passed at Connectathons (more again this year)
22 modality products (CT, XA, DR, MG)
All major CT vendors were shipping REM support in 2012.
17 archive products, 15 dose “consumer” products
4 dose reporters, 1 dose registry
NEMA XR-25 – CT Dose Check
most new products
Products exist and have been rolling out over the last few years.
The message is: There is no reason not to start now.
Time to get started…

6. What about my legacy CTs?
Some of you may have old systems. Don’t let that stop you, we’ll talk about that too.
There are ways to bring that in too. (Picture of Chitty-Chitty-Bang-Bang?)
We’ll talk about legacy integration strategies.
And if you are already doing all this, write up your experiences, we’d love to have you presenting next year.

7. We’ll talk about that too…

8. Standards & Tools
You believe managing dose is part of the practice of radiology. What’s your plan?
On average, what’s your dose for an adult chest CT without contrast? How are you going to get started?
You could give your techs a pencil and a dose log sheet. It’s easy. But it’s not scalable or detailed.
Scalable – not just on Friday afternoons

9. Learning Objectives
1) DICOM Radiation Dose SR (RDSR) - capturing procedure dose information 2) IHE Radiation Exposure Monitoring Profile (REM) - coordinating the capture and management of RDSR objects - applying in a radiology practice. 3) "CT dose screens" - porting legacy scanner data into RDSR 4) MITA CT Dose Check (XR-25) - pre-scan dose pop-ups on the CT console 5) IHE Integration Statements & DICOM Conformance Statements - specifying these standards & features when purchasing and integrating radiology systems.
The Plumbing

10. Headers & Screen Shots Useful but limited Missing details
Not machine-readable
Duplication issue
Size issue 10

11. Radiation Dose Structured Report
DICOM RDSR
Radiation Dose Structured Report
Object

12. DICOM Dose Reports “SR Objects” – DICOM Structured Reports
Easily ingested (and regurgitated) by PACS
Granularity : “Irradiation Event”
& Accumulated Dose over Study, Series
Templates :
CT, Projection X-Ray (Mammo, Fluoro, DR/CR)
PET/NM (2014)
Not addressed: RT

13. Key Measurements CT Dose Projection X-Ray Dose Mammography Dose
DLP, CTDIvol, kVP, mA, sec, …
Effective Dose [ Optional; Reference estimation method ]
SSDE (CP-1170) [ Optional; see AAPM 204 ]
Projection X-Ray Dose
DAP, kVP, mA, sec, …
Fluoro Dose, Fluoro Time
CR/DR: Exposure Index, Deviation Index
Mammography Dose
AGD, Entrance kVP, mA, sec, …
Compression, Half Value Layer
Mention WG-28 work to upgrade the pipeline to address organ dose, etc.
ftp://medical.nema.org/medical/dicom/2011/11_16pu.pdf

14. Other Details in Dose SR
Full Patient / Order / Study Details
Unique ID for each Irradiation Event
Equipment ID, Ordering Doc, Performing Tech
Patient Size, Orientation, Anatomy Imaged
Imaging Geometry
X-Ray Filtering & Collimation Details
Anode Target Material
Calibration, Phantom, Dosimeter, Patient Model

16. Radiation Exposure Monitoring
IHE REM Profile
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Numerical Details
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Radiation Exposure Monitoring
Final Text in 2011, Folded into IHE Radiology Technical Framework in 2012
(Introduced in 2008, in recent years users have actually started asking for it.

17. IHE in One Slide
IHE helps vendors implement & test functions that span multiple systems
Profiles are implementation guides
how to use existing standards
to address a specific problem scenario
Connectathons are test events
managed testing of Profile implementations
IHE helps users purchase & integrate multi-system solutions
list required IHE Profile support in RFPs
Connectathon: one week, 100+ vendors, 550+ engineers, thousands of tests. Non-trivial.

18. IHE Radiation Exposure Monitoring Profile
National Registry
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Numerical Details
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Outlier: #
Performing Phys.
Over Target: 12.2%
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Numerical Details
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Dose Information
Reporter
Archive
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Numerical Details
Final Text
RDSR goes into the study record, onto CDs, etc. etc.
Highlight that the Archive can be bypassed if need be, and that various innovative Dose Consumers can be incorporated
And it’s a Pipeline. New fields will periodically be added to the RDSR, systems will start populating, and it all follows the same pipeline.
(Spirit of not letting Perfect be the enemy of Good)

19. Using SR Dose Reports Radiation QA Regulation
Periodically Query / Retrieve Reports from Archive
Set policies/standards and flag deviations
Set goals for improvement and track progress
Implement protocol changes and compare difference in dose
Regulation
E.g. Automatically insert dose metrics into diagnostic reports
Patient Impact Evaluation
e.g. if Patient identified as pregnant post-facto
Dose Mapping
Store data in realtime from Modality to Mapping Workstation

20. Using SR Dose Reports National Registries Individual Dose Record
Anonymize and submit Dose Reports to Registry
Compile Population Risk Estimations
Derive Dose Reference Levels (DRLs)
Provide Site-Site Comparisons
Individual Dose Record
Collect Dose Reports over time
Clinical Trials
Collect Dose together with Images
Demonstrate both improved detection & reduced dose

21. Legacy Dose Extractors
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Numerical Details
Getting older systems into the same pipeline – do OCR and generate proxy RDSRs

22. Legacy Extractor What if you can’t get REM?
Extractors create (partial) REM objects
Based on OCR of dose screens
Based on image header contents
Based on MPPS
Likely incomplete but still useful
Allows use of uniform infrastructure (RDSR)
Current focus: CT, some XA
Date
Patient ID
DLP
CTDIvol
Patient Weight
Scan Duration
SSDE
Incomplete - likely to be missing patient weight, procedure details, fine grained information, phantom information, etc. etc.
Filter

23. Example Extractors Open Source
“Dose Utility” - dclunie.com
by David Clunie (PixelMed)
“Radiance” - radiancedose.com
by Tessa Cook (Hospital of U of Pennsylvania)
“GROK” – dose-grok.sourceforge.net
by Graham Warden (Brigham and Women's Hospital)
Also
ACR Triad Site Server (included in ACR participation)
by Mythreyi Chatfield (ACR)
… and a growing number of commercial products

24. Predicted DLP of 981 mGy-cm
MITA XR-25
CT Dose Check
Dose Notification
Predicted DLP of 981 mGy-cm
Exceeds Threshold …
Going to Final Text in 2011

25. MITA CT Dose Check Initiative
Goals
Enhance dose awareness (CTDI/DLP)
Help to avoid excessive radiation events
Provide data to sites for QA
MITA has published the standard (XR-25)*
Manufacturers worked to ensure
Uniformity
Speed of implementation
Breadth of deployment *

26. Dose Notification Pop-up message
Notifies technologist that dose for a current scan element will exceed a trigger value
Tech may:
confirm and proceed, or
go back and adjust scan parameters
System records audit trail
Predicted dose, Notification value, Date/time, diagnostic reason, etc.
Clinical sites set values that will trigger a notification
Can set DLP and/or CTDIvol values for each scan element
e.g. head without contrast
Defined by the clinical site for their patient population

27. Dose Alert Pop-up message
Alerts technologist cumulative dose for current study will exceed a trigger value:
CTDIvol (summed at each patient location)
DLP (summed over the current study)
Tech may:
enter their name, (& a password if configured), confirm and proceed, or
go back and adjust scan parameters
Clinical sites set values that will trigger an alert
Can set DLP and/or CTDIvol values
System must allow at least one global value
System tracks accumulated CTDIvol at each patient location & accumulated DLP
System checks predicted accumulated dose indices when protocols are saved & when scans are ready to run
Site can facilitate a variety of policies based on how they activate and distribute password.

28. Default Values
FDA has suggested an alert value for CTDIvol of 1000 mGy
AAPM notification value suggestions
Can be changed at local site
Triggers vs. DRLs 75th percentile -> popups on 25% of scans
Consider behavior modification vs. alert fatigue

29. Audit Trails Pop-up Overridden? System must record:
Dose Notification
Predicted dose, Notification value, Date/time, Diagnostic reason
Dose Alert
Predicted dose, Alert value, Date/time, Diagnostic reason, Operator name
RDSR has fields to record all these details
May choose to record even if not overridden

30. Finding Products IHE REM DICOM RDSR NEMA XR-25 Dose Check
Testing: IHE Connectathon
Product: IHE Integration Statement
DICOM RDSR
Product: DICOM Conformance Statement
NEMA XR-25 Dose Check
Vendor commitment; most new products 30

31. Ask for it During RFPs / Purchase Requirements
… shall support IHE REM as the Acquisition Modality actor …
Ask to see IHE Integration Statements & DICOM Conformance Statements
During Installation / Acceptance
Discuss activation / configuration
During Upgrades
Some models can be upgraded

32. Takeaway Collect Your Data New/recent Modalities Legacy strategies
IHE REM / DICOM RDSR to capture dose data
Legacy strategies
Dose extractors to generate RDSR data
Analyze Your Data
IHE REM – Dose Information Reporter for local analysis
ACR Dose Registry to compare to benchmarks
Facilitate Prevention
CT Dose Check for configurable pre-scan alerts
BUT this is not a radiation safety program in a box. These are tools.
You need to understand the metrics for what they are (and aren’t), and implement a program to record/analyze/apply them sensibly

33. ACR DIR
Dose Index Registry

34. ACR Dose Index Registry
nrdr.acr.org
Open to facilities worldwide
Anonymized data submission
(via IHE REM or legacy extractor)
Provides periodic reports
Dose statistics
Site Comparisons
Modest annual participation fee
Note: ACR was early collaborator for IHE REM profile 34

35. ACR Activity Tracking practice Understand current dose patterns
Provide basis for establishing DRLs
Not tracking patient/longitudinal
Procedure Naming Issue
Comparison requires consistent naming
Local consistency vs National consistency
ACR maps to Radlex Playbook (w Mapping Tool) 35

36. 2Mil+ Exams recorded