Radiation Dose Profile - Detailed Proposal

1. Proposed Profile: Radiation Dose Management Profile

Proposal Editor: Joel Chabriais/Bernard Aubert/Kevin O'Donnell
Profile Editor:
Date: N/A (Wiki keeps history)
Version: N/A (Wiki keeps history)
Domain: Radiology (SFR, ACR, AAPM, IRSN, RSNA, FDA)

Summary

It is difficult to monitor radiation dose for individual patients and almost impossible to assemble and compare such statistics for a site or a population or a type of exam.

DICOM has an SR format for radiation dose events and a protocol for exchanging them.

A Radiation Dose profile could require compliant radiating devices to produce such reports and could define transactions to actors that collect, analyze and present such information.

Euratom and ACR have published guidelines requiring/encouraging dose tracking. Individuals from SFR are willing to participate in Profile development.

The main challenges are dealing with the chicken-and-egg problem and avoiding inconsistent implementations.

2. The Problem

Tracking radiation dose delivered to patients for medical purposes is gathering increasing attention from professional societies and regulatory groups. Publications include: European directive Euratom 97/43, ACR Dose Whitepaper and some Japanese regulations.

Many such groups have expressed a desire to establish standards of practice based first on a quantitative understanding of current practice, however they have found it prohibitively difficult to collect such data. Needs have been expressed to track both dose to individual patients and to assemble population data.

Physicians are asked to follow guidelines, like constraining their patients dose to As Low As Reasonably Achievable (ALARA), but it can be difficult for them to see what their patient dose actually was, and almost impossible to assemble comparison values as to what is reasonably achievable.

In most of the world, although it should be, it is not possible to do things like:

view the dose a patient (or particular organs) received for a certain exam, hospital stay or course of treatment
view a patients cumulative dose history
determine if a given patient dose exceeds maximum guidelines or is otherwise an "outlier" requiring investigation
compute the population "dose profile" for a certain hospital or region
compute the population "dose profile" for a certain pathology
compare "dose profiles" against other sites/regions, against local policy targets or against standards of practice

In the vast majority of medical procedures involving radiation, the potential benefit to the patients health far outweighs the potential risk, but the tradeoff should not be forgotten, and without the support of technological mechanisms, a concious evaluation if the tradeoff is seldom done.

The problem is that although standards exist (see below) such dose tracking has not been widely deployed due to:

difficulty coordinating the roles of the different equipment involved (which actors should do what)
difficulty coordinating tracking across multiple departments and multiple institutions
the need to converge on one of the available standard approaches
a chicken-egg situation between the dose record producers, the dose record receivers and the dose record consumers

These are, of course, many of the typical problems that IHE is used to addressing.

3. Key Use Case

First use case scenario

Frank Smith is hospitalized following an automobile accident.

The ER doctor sends him for an abdominal CT. Later, his attending physician sends him to Radiology once for a chest X-ray and twice for a right arm and left leg X-ray. A referral to Cardiology results in a coronarography (fluoroscopy and radiographies were done).

The hospital would like to believe its doctors are following site policy and its practices are in line with national norms, but doesn't know if that is actually true and has little or no data to back it up. It has little or no tools for implementing a dose management or reduction plan and no tools to measure progress towards its targets.

Some of the modalities included a few dose details in the headers of the images. Those images are distributed across the Radiology and Cardiology PACS systems. A few of the Reporting workstations display dose values some of the time when the details in the image header match what it expects to find. Other systems put dose details in some of the MPPS messages sent to the RIS and the CIS. All the HIS knows is the names of the radiology procedures ordered. No system has a complete view and due to inconsistency of data format and distribution, none of them attempt to compile a dose record.

Correlation with Mr. Smith's radiotherapy earlier this month and again next month at the clinic across town is completely out of the question.

Second use case scenario

When Mr. Smith's order is placed, the system can provide guidance to the physician, taking into account the dose of considered procedures and current patient dose.

At the end of the stay, the HIS knows all ionizing radiation events that occurred during the stay of Mr. Smith, keeps track of all data and calculates and archives the total dose delivered during the stay. Mr. Smith had several visits to this hospital before. The HIS consolidates the total radiation dose delivered through all visits. Data is sent to the regional EHR sytem to be consolidated with other enterprises Mr. Smith visits during his life. Data is also transmited, after anonymization, to a national radiation dose registry. The registry provides periodic reports back to the facility with regional and national benchmarks of radiation dose. Using this report, Mr. Smith’s hospital can compare its dose profile by modality, exam type, and pathology to facilities of the same type, in the same region, and to the nation as a whole.

4. Standards & Systems

Some existing systems that might be involved include:

Systems that schedule studies (RIS), administer radiation (modalities, and therapy systems), and store and report the results (PACS?, HIS?, EHR?)

Some standards which might be relevant to the solution include:

DICOM SR Dose objects (PS3.3 A.35.8 X-Ray Radiation Dose, Supp 127 CT Radiation Dose)
DICOM IOD’s attributes (CT IOD, XR IOD, etc.)
DICOM MPPS attributes
Other standards in radiotherapy and nuclear medicine? (PS 3.3 A.18 RT Dose?)
Dose measurement protocols and guidelines from professional and/or regulatory bodies

5. Technical Approach

<This section can be very short but include as much detail as you like. The Technical Committee will flesh it out when doing the effort estimation.>

Existing actors

Existing actors that could be used or might be affected by the profile:

Acquisition Modality
Image Archive?
RIS
HIS

New actors

Possible new actors:

(Dose) Archive
(Dose) Display

Existing transactions

<Indicate how existing transactions might be used or might need to be extended.>

New transactions (standards used)

<Describe possible new transactions (indicating what standards would likely be used for each. Transaction diagrams are very helpful here. Feel free to go into as much detail as seems useful.>

Impact on existing integration profiles

<Indicate how existing profiles might need to be modified.>

New integration profiles needed

Consider a Radiation Dose Management Profile. At the very least, coordinate how systems that deliver dose should electronically report it, and how that information can be archived and accessed.

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.>

6. Support & Resources

Members of SFR have indicated their support for this work and Joel Chabriais & Philippe Puech have agreed to participate in development. Bernard Aubert representative of IRSN will participate to provide expertise on radiation dose follow-up issues. IRSN is thinking on a National Radiation Dose Registry in France.

Members of ACR have indicated their support for this work and Laura Coombs & David Channin have agreed to help write the profile. They are particularly interested in the role of a Dose Registry since Laura at ACR is currently working to establish such a registry. Paul Nagy from SIIM/UofMaryland is also involved in the ACR Dose Registry project and would like to contribute and review the work.

Members of SEFM (Spanish Medical Physicist Society) have been "waiting a long time" for such work and would like to support the work. Julio Almansa has agreed to participate.

Dr. Wallis of SNM has offered to provide input on Nuclear Medicine.

Some additional background

CR Dose Tracking Article in Aunt Minnie

Final report by The UK Clinical Advisory Committee on diagnostic imaging on the safety and efficacy of CT screening - July 2007 expresses a need for an integrated framework for policing and compliance of national and international protocols for radiation exposure.

The French Ministry of Health (Roselyne Bachelot), decided in July that Radiation Dose Follow-up is now a major work item for the ministry. The ASN (Agence de Sûreté Nucléaire - Nuclear Safety Agency) is now in charge to develop the necessary infrastructure. On September 10, ASN and IRSN (Institut de Radioprotection et de Sûreté Nucléaire - Radioprotection and Nuclear Safety Institute) will meet at SFR (Société Française de Radiologie - French Radiological Society) to work on "Integration of Radiation Dose delivery for medical imaging examinations and links to the Patient Folder".

Dose DataMed, a project granted by European Union wished such a work for a long time and is happy about this proposal and will possibly provide some support.

7. Risks

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

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.>

How should manual entries be handled: In CR, often the X-Ray device, dosimeter and CR reader are from different vendors and not connected. Manual entry could also handle legacy systems. Would a PC supporting manual entry be indistinguishable from a Modality actor in this profile? If so, maybe they just claim to be modalities. Could a CR reader submit an SR dose report? Is there enough data CR IODs?

The initial focus is on X-ray based diagnostic devices. Do we want to address SPECT and PET imaging now? Do we also want to address therapeutic devices in this profile? Bedside devices? Substances? (seeds, radionuclides)

Controversies do exist over what are the most relevant/useful measurements to make and how those should be be interpreted. An IHE Profile will need to limit requirements to common denominator measurements and to empower analysis but not to dictate interpretation/policy.

First priority is to begin capturing the data using standards. Later it may be useful to tie this into the National Registry Submission work being done in IHE Cardiology and IHE Quality.

It may be necessary to choose a simple, but standardized dose exposure unit that could help simplifying exposure calculation for exposures to modalities that do not allow manual input and then, provide objective data. If manual input is allowed, then calculations should be clearly marked as potentially erroneous.

9. Tech Cmte Evaluation