Radiation Dose Use Cases

The Radiation Dose Profile is intended to facilitate a variety of radiation dose related Use Cases.

Generally, the Profile will not directly mandate feature details (such as the contents or scope of summary reports a hospital dose information manager system might generate for policy monitoring), but it will attempt to mandate sufficient infrastructure (such as the transactions to get the necessary dose details from modalities to a dose information manager) to make it feasible for products to implement the features to meet the use cases.

This page is a discussion area to flesh out various use cases. They will be used as test cases for the specification in the Draft Profile.

Where possible, include details such as specific attributes, analysis methods and report contents.

Example of some of the problems

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 divided 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.

Broad Scenario from the Profile Proposal

When Mr. Smith's order is placed, the physician can query the system about 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 system to be consolidated with other enterprises Mr. Smith visits during his life.

Data is also transmitted, 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.

Regulatory Use Case

Several groups interested in regulatory issues (IEC, FDA, AAPM, etc) drove definition of the DICOM Dose SR Objects in the first place. How do they envision the objects being used?

ACR will collect dose information at a national level, but not directly for regulatory purposes. (Analysis of the collected data might inform guidelines that could find their way into accreditation).

Germany and Netherlands dose information does not go above the Hospital level. Dose information is required and must be auditable.

Registry Use Case - ACR

ACR is forming a national registry for Radiation Dose. The initial focus is CR, DR and CT. They have not yet thought through the implications for diagnostic or interventional XA.

The primary function is to benchmark dose protocoling with the goal of minimizing dose to the population.

ACR is interested in collecting a cumulative log:

“Protocol used”
Reason for exam?
Patient gender, age – to permit age/sex specific guidelines (different risks)
Patient weight – affects dose, affects imaging, used in guidelines
Patient ID (pseudonymized) – to evaluate individual dose histories
Technologist ID (pseudonymized) – to compare inter-operator variability
Time of acquisition? – to compare shift variability?
Equipment details
Date of Last Calibration – affects dose? Want to track compliance?

ACR has no plan to become a national personal dose record but are very interested in collecting data about “frequently scanned patients” and the cumulative dose.

Records should be at the encounter level.

The ACR service would be to review the performance of a given hospital against the benchmarks and perhaps provide performance summaries for “comparable” facilities.

The ACR benchmark report is your report card. Benchmarking will be challenging because technology moves very quickly. Higher levels is not necessarily bad. Various factors can impact.

Hospital Use Case – Impact Evaluation of Specific Patient

After one or more scans have been completed, the patient is identified as pregnant. (This was not identified before the scans because tech didn’t ask, patient misunderstood, patient didn’t know, etc.)

Hospital wants to retrieve the recent dose records for the patient and perform a calculation/analysis to estimate the risk/impact to the patient/fetus.

Important analysis details include time/date of scans, body area irradiated, exposure values.

Important process improvement details include date/time of scans, tech names, ordering physician.

Hospital Use Case - Policy Compliance Monitoring

Hospitals generally have policies relating to patient radiation dose. They would like to have tools to help them monitor whether those policies are being followed.

Might want to look at average patient dose for each tech, for each shift, for each room.

Breakdown by patient age group, weight group, gender, procedure,

In theory, this is one way to counter dose creep. Image quality sets a low side limit on dose (too low and the images are unacceptable to the radiologists). Policy can be used to set a high side limit then monitor and encourage people to stay on the right side of the limit.

Hospital Use Case – Prevention / Improvement

Hospitals would generally like to reduce patient dose and prevent unnecessary, unwarranted or excessive radiation exposure.

EMR Use Case - Patient History / Preferences

patient talks to specialist and doesn't want a new scan
the details should be in the patient history
docs often don't think about it, we need to raise the flag, then give them details
important to note that this has to go to the doc

Techs will alert the rad when the order comes in. Rads are responsible for the tech behavior.
- tech may have some opportunity to bias the study to lower dose based on internal policy

Clinical Trial Use Case

A site proposes a low dose CT lung screening procedure but currently it's difficult to quantitatively demonstrate/validate the dose benefit, they can only report on the detection rates.

This profile could enable lots of such studies.