Respiratory Correlated Imaging - Brief Proposal
- Proposal Editor: Scott Hadley University of Michigan Radiation Oncology swhadley@umich.edu, Chris Pauer Sun Nuclear Corporation chrispauer@sunnuclear.com
- Proposal Contribtors: Kevin O'Donnell
- Editor: <Name of candidate Lead Editor for the Profile, if known>
- Domain: Radiology
Summary
Imaging modalities are inconsistent about how they encode the respiratory phase information in studies used for RT treatment planning.
This creates safety and efficiency problems.
The profile could mandate standard encoding for how the information is stored by the modality and interpreted by the planning system. DICOM has fields for this.
Several vendors are interested in addressing this, as is IHE RO, AAPM and RSNA.
2. The Problem
Respiratory correlated imaging is a requirement for motion management in radiation therapy. The motion of tumors and normal tissue is used in the planning process to develop RT plans. Treatment delivery devices acquire 4D images (3D over time) that need to be compared to previous 4D images to complete patient treatment.
Currently there are variations in implementation by vendors producing and consuming these types of images. In particular, different methods are used to communicate the respiratory phase for each image series. As a result, users often need to manually update or correct the data in the DICOM images so that the consuming software system can correctly display and use the 4D image for treatment planning.
Safety hazards exist. If 4D images are tagged incorrectly, this may produce incorrect treatment plans. Users could make a mistake correcting this data for use with planning systems. Time is wasted by users modifying data for treatment planning.
Standardized implementation of 4D reparatory correlated imaging would resolve these problems.
3. Key Use Case
- Imaging device produces several imaging series in the same FOR where each series represents a different phase of respiration of the patient.
- User sends 4D respiratory correlated CT/MRI/PET/… images of the abdomen for planning a free breathing pancreas radiotherapy plan.
- The treatment planning system is expecting that the inhale phase is tagged “0%” and the exhale phase as “50%” with other phases with corresponding tags.
- 4D respiratory correlated data instead sends text descriptions of “inhale” and “exhale”.
- User is required to edit series descriptions to add the text “0%” or “50%” for correct interpretation by the planning system.
4. Standards and Systems
Systems
- Acquisition Modality (CT, MR, etc)
- PACS
- Treatment Planning System
Standards
- DICOM IODs
- Series Description is currently being used as a workaround.
- Respiratory Syncronization Macro is perhaps the correct technical solution
- DICOM WG7 may also be working on a future solution
5. Technical Approach
Existing actors
- Acquisition Modality
- Image Manager/Archive
- IHE-RO Geometric Planner?
New actors
- None
Existing transactions
New transactions (standards used)
- "Store Images with Respiratory Details"
- Could continue loading (RAD-8) Modality Image Stored with a Profile specific requirement
- Could clone RAD-8 and de-reference most of the content
Impact on existing integration profiles
- Maybe some IHE-RO Profiles?
New integration profiles needed
- Respiratory Correlated Imaging Profile (like other Image "Content" profiles in Radiology)
Breakdown of tasks
Transactions
- "Store Respiratory Image" - cloned transaction or new chunk in RAD-8
- SP: 1-effort, 1-complexity
- Confirm existing Q/R is adequate and tweak if needed
- SP: 1-effort
- RO has not indicated any difficulty in finding the correct series, but we can ask
Profile
- Simple profile - three actors; store-retrieve
- SP: 2-effort, 1-complexity (respiratory gating/RO)
- Use case is "Store-retrieve"; probably doesn't merit a point.
- SP: 0
- No mappings or options
- No expected DICOM CPs
Topics/Debates
- Confirm what attributes to use for phase information, and confirm scaling
- SP 1-uncertainty
- Decide packaging - Profile, or Option on SWF?, Something else?
- SP 1-uncertainty
- Decide new transaction or extend RAD-8
- SP 1-uncertainty
6. Support & Resources
- IHE-RO supports this but thinks it may be more appropriate to IHE-RAD
- AAPM would like to see a solution
- Scott and Chris are willing to work on the Profile
7. Risks
<List technical or political risks that will need to be considered to successfully field the profile. Demonstrate to the TC/PC your understanding/appreciation of the problem space>
8. Open Issues
<Point out any key issues or design problems. This will be helpful for estimating the amount of work and demonstrates thought has already gone into the candidate profile.>
9. Tech Cmte Evaluation
Candidate Editor:
- Scott w either Kinson or Kevin as Mentor 2 - uncertainty
Effort Evaluation (as a % of Tech Cmte Bandwidth):
- SP: 11 20%