REM for Radiopharmaceutical Imaging - Proposal

1. Proposed Workitem: REM for Radiopharmaceutical Imaging

• Proposal Editor: Jeff Pohlhammer
• Editor: Jeff Pohlhammer or Charles Smith (Co-authors of DICOM Sup159)
• Domain: Radiology

Summary

Performers of PET or SPECT scans (which image radioactive materials administered into the patient's body) would like to track, analyze and reduce the patient dose, similar to the work done on CT dose, but they lack tools to make it easy/automatic.

DICOM has final texted Sup159 (Radiopharmaceutical Radiation Dose Reporting) which makes a new SR object that mirrors the RDSR that we used for IHE REM for CT and X-ray radiation dose .

The "front half" of the Profile would require the creation and distribution of the new SR object. The "back half" of the profile would be the same as IHE REM.

Modality (Philips) and IT vendors (Numa) have already demonstrated interest and brought resources. Interest has also been expressed by individuals at Mallinkrodt/WashU, QIBA-PET, and Memorial Sloan Kettering.

This would be a logical continuation of the work in IHE REM.

2. The Problem

First, regulatory bodies are reviewing procedures for administration of radiopharmaceuticals and are beginning to require that radiopharmaceutical-related dose information be tracked and reported, similar to what has occurred for X-Ray-based radiation dose. The DICOM Standard now includes a Structured Report object (Sup159) suitable for reporting radiopharmaceutical dose, but guidance is needed on how to make use of these report objects in the clinical setting.

Second, the administration of radiopharmaceuticals for nuclear medicine procedures generally occurs prior to imaging procedures, and is not done at the imaging system. But the NM and PET Image IODs require entry of information such as the pharmaceutical and isotope in use, and the amount of activity administered, and the time of administration. This often means that operators are manually transferring information from a lab system to the imaging system, leading to errors in recording the proper activity and time of administration. Such errors can lead to compromises in image quality and errors in quantitative measurements for things like SUV.

Value Statement

Adoption of a Profile to address reporting and management of radiopharmaceutical dose will satisfy the needs of the regulatory bodies, and provides both the regulatory bodies and clinical community a means for tracking and reporting radiopharmaceutical-related patient dose in a manner similar to that already adopted for ionizing radiation via the REM Profile.

There are savings in infrastructure cost, procedure and technical complexity to be gained by adopting a Profile that is similar to the existing REM profile, making use of many of the same actors and concepts.

This Profile will specify the actors that will create the associated dose reports (the lab and dose creation/administration systems) and that the imaging systems will consume these reports to obtain dose information automatically. This will eliminate the errors associated with manual transfer of such information, reducing the number of repeated scans due to bad image quality and incorrect SUV measurements. So the Profile would provide operational/workflow benefits in addition to the dose management benefits of REM.

3. Key Use Case

• A patient enters the nuclear medicine lab and is injected with a radiopharmaceutical in preparation for a nuclear medicine imaging procedure that is to be performed later that day.

• The lab technician jots down the amount of activity and time of injection, for use by the imaging technician later.

• When the patient arrives at the NM department later for their imaging procedure, the operator types in the previously recorded dose information as part of setting up the scan.
  • Transcription errors, and differences in clock times between the lab and imaging systems can all contribute to errors at this point.

The hospital would like to create and track dose reports for these procedures. They already do so for their CT systems, but there is no agreement on a workflow to accomplish the same automation of reporting for the radiopharmaceutical dose information. Some of their lab systems may be able to generate reports, but the format is not standardized. Likewise, the nuclear medicine imaging systems in the hospital may not be able to consume these reports, and some of these imaging systems may generate their own reports as a surrogate for the lab systems – again in a variety of formats.

4. Standards and Systems

The same systems that are involved in the REM Profile would also be involved in this new Profile, with the addition of the dose creation/calibration systems in the "Hot Lab" and/or injection systems.

The modalities will be PET and SPECT scanners (including PET/CT, PET/MRI, etc).

The DICOM Standard provides the structured report template to be used for the RRD (Radiopharmaceutical Radiation Dose) dose reports.

• New Object - http://medical.nema.org/medical/dicom/2014a/output/chtml/part03/sect_A.35.html#sect_A.35.14
• New Template - http://medical.nema.org/medical/dicom/2014a/output/chtml/part16/sect_RadiopharmaceuticaRadiationDoseSRIODTemplates.html#sect_TID_10021

5. Technical Approach

Follow the REM architecture with a few modifications described below.

New actors

• Dose "Creator"?

• The RRD is ideally created by the dose creation/calibration systems in the nuclear medicine "hot lab", which knows the critical details of the radiopharmaceutical dose that was prepared/administered.
• Might also consider the injection systems in the nuclear medicine imaging suite.

Existing actors

• Image Manager

• Keep doing Store/Query/Retrieve of SR objects, so almost no change

• Dose Information Reporter, Dose Registry

• Same jobs as in REM, but when parsing the SR handle the RRD data elements that differ from RDSR.

• Acquisition Modality

• Likely becomes a consumer of the dose report instead of the creator. Details about the radioactive material used, it's strength and when it was prepared are used by the modality to correct the images for decay, scatter, etc as well as being copied into the image header.

Existing transactions

• Most of the existing REM transactions can be used as is, or with simple variant text added to reference the new payload flavour.

New transactions (standards used)

• Might create a new transaction (cloning existing REM transaction) to handle how the PET/SPECT system finds/gets the RRD.

New integration profiles needed

A new Profile is proposed. The main reason for not simply introducing an option in REM, is to give it visibility, and call attention to the difference in architecture/dataflow (TO the modality, not FROM) and domain (NucMed versus X-Ray).

Impact on existing integration profiles

No significant modifications. Might want to mention the new profile in the "Related Profiles" section of REM and mention the payload in transport profiles. Also maybe a mention in Scheduled Workflow that this profile supplements SWF.b for Nucmed systems.

Breakdown of tasks that need to be accomplished

<A list of tasks would be helpful for the technical committee who will have to estimate the effort required to design, review and implement the profile.>

• Review existing REM transactions for payload dependence.
• Decide on dataflow pattern from hotlab to modality

The Profile can also address the special case of a nuclear procedure that includes administration of dose to the patient, but does not include an imaging procedure.

The Profile adopts a single standard format for the reports (DICOM RDSR) and specifies the information flow from dose creator, to dose repository, with the modality retrieving reports as needed to populate information needed when creating the NM and PET image IODs and for starting an imaging procedure.

IHE is the right place to address the issues described above. IHE has already addressed similar issues in the REM profile, so it makes sense to resolve the same problems in the nuclear medicine domain. With the entire PET modality market, and increasing percentages of the NM modality market being hybrid systems, it makes sense to have a common solution for reporting dose from both the radiopharmaceutical and X-Ray contributions in a similar manner.

6. Support & Resources

<List groups that have expressed support for the proposal and resources that would be available to accomplish the tasks listed above.>

<Identify anyone who as indicated an interest in implementing/prototyping the Profile if it is published this cycle.>

7. Risks

<List technical or political risks that will need to be considered to successfully field the profile.>

8. Open Issues

Could use query/retrieve transactions to locate dose reports and match them up with imaging procedures to be performed (these procedures could be Scheduled Procedures defined in Modality Worklist, or unscheduled procedures).

9. Tech Cmte Evaluation

<The technical committee will use this area to record details of the effort estimation, etc.>

Effort Evaluation (as a % of Tech Cmte Bandwidth):

• 35% for ...

Responses to Issues:

See italics in Risk and Open Issue sections

Candidate Editor:

TBA