Radiation Dose Summary for Diagnostic Procedures on FHIR

Please consider that this page is outdated. The latest content of this topic is under this link : https://build.fhir.org/ig/HL7/fhir-radiation-dose-summary-ig/

Problematic

The IHE Dose Reporter actor from the IHE REM profile gather Radiation information and dose reports from modalities. However, there is no standardization of the exposure of the gathered data to third parties in light format/API. 

 Dose Management systems need to share information related to the exam to multiple third parties :

• Mobile Applications: like patients related mobile application, where a patient may want to centralize the report of doses injected to him
• RIS/EHR : many RIS/EHR systems does not have capabilities to read DICOM SR documents and prefer to contact the hospital dose registry in order to gather a summary of the dose report; and in order to include the summary under the final imaging report.
• Third backend systems: some third backend application may want to gather a summary of the exam’s dose for some proprietary use; gathering the complete RDSR is useless for most of the non Dose Management systems

The RDSRs have a complete and a strong structure for sharing the dose information from the modalities to the Dose Consumer/Reporter actors, and also between the Dose Reporter and the Dose Registry systems. However, most of third party application have a very light needs for the Dose report. For example, RIS systems in France needs only for CT Dose Length Product Total from the CT RDSR, in order to fit local reglementations. 

The emergence of HL7 FHIR simplified the exchange between backend applications and third parties through the exchange of normalized resources. This analysis allows to share minimal dose information through FHIR resources.

Scope

• Scope
  • Share a summary of dose information by exam through FHIR
  • Irradiations received by the patient
  • The targeted modalities are CT/XA/RF/MG/NM
• Out Of Scope
  • Share details of the radiation administration
  • Share enhanced data (SSDE, Organ Dose, etc) to third applications
  • Irradiations received by the practitioner

Use Cases

Three use cases were identified.

Use case 1: Imaging report construction

• The Patient perform an irradiating exam within a modality.
• The modality share the dose report to the Dose Management System, which may implement the IHE REM Dose Reporter actor. This dose information sharing can follow the REM profile schema. 
• After analysing the exam images, the radiologist sends its notes to the Radiology Information System (RIS).
• In order to construct the final imaging report, the RIS needs to gather a minimal summary of the dose received by the patient. The RIS send a query to the Dose Registry and get minimal dose information report.
• The response is then integrated to the final report, which can be a CDA report following the DICOM Imaging report specification in PS3.20.
• The final report is shared with the hospital EHR or with the regional/national radiology report repository, through IHE XDS-I.b for example.

This use case is very common within RIS systems not supporting dose management modules. In fact, gathering of dose information from modalities can be very complex:

• It is based on multiple sources of data: RDSR, MPPS, SC & OCR, and DICOM images header.
• The reporting of the dose information by the modalities may contains misinterpretations and errors

It is the role of the Dose management system to provide the RIS with the right information regarding the dose administered to the patients. Reporting the minimal dose information inside the final imaging report is recommended by many stakeholders and organizations, and sometimes it is a reglementation. For example, in France there are the Order of 22 September 2006 relating to the dosimetric information to be included in an act report using ionizing radiation, from the French Minister of Health and Solidarity, and describing some dose information that need to be present in the final report. Here is an example of french RF exam with some dose data:

The same kind of regulations exists in California in the US about the CT exams, which is the Senate Bill No. 1237. Here is another example following this regulation (the example is from the reference 15, AAPM, Experience with California Law on Reporting CT Dose) :

Use case 2: Mobile applications access

The exposure of the Dose Summary as FHIR resources open the doors to the mobile applications to gather the dose information from the Dose management systems, or from the EMR if the Dose Summary is propagated to the EMR. Many applications may benefit from this additional patient data in order to add tracking of the patient dose information. Some patient facing applications can track the dose summary through multiple facilities and then concentrate the dose data. Other practitioner mobile applications can benefit from the Dose Summary data in order to collect more data for practitioner, or to improve their Clinical Decision Support (CDS) component.

Use case 3: Business Intelligence

The exposure of the Dose Summary as a FHIR resources is beneficial for Business Intelligence application exposing metrics on dose data. In fact, multiple metrics can be normalized within a FHIR server collecting the Dose Summary resources, like:

• Comparison of average of Dose between modalities
• Comparison of average of Dose between facilities/hospital
• Comparison of dose administration characteristics between patient cohorts
• Comparison between dose administration levels between regions within a national FHIR server

Minimal Dose Information

Identification

In this paragraph we analysed the mapping between the identified minimal dose information and some specifications on dose information reporting coming from multiple stakeholders:

• DICOM PS3.20: Imaging Reports using HL7 Clinical Document Architecture
• DICOM PS3.16: Content Mapping Resource
  • X-Ray Radiation Dose SR IOD Templates
  • CT Radiation Dose SR IOD Templates
  • Radiopharmaceutical Radiation Dose SR IOD Templates
  • TID 2008. Radiation Exposure and Protection Information
• France guidelines
  • French Society of Radiology - SFR, Practical Guide for Interventional Radiology (Guideline - 2013)
  • High Authority of Health - HAUS, Patient radiation protection and analysis of CPD practices and certification of healthcare establishments (Guideline - 2012)
  • Presentation of the main radiation protection regulatory provisions applicable in medical and dental radiology (Guideline: 2016)
  • French Minister of Health and Solidarity, Order of 22 September 2006 relating to the dosimetric information to be included in an act report using ionizing radiation, (Order - 2006)
• Finnish Imaging Report specification, KanTa Imaging CDA R2 document structures (2013)
• US, California State
  • AAPM, Computed Tomography Dose Limit Reporting Guidelines for Section 3 – 115113
  • Senate Bill No. 1237, CHAPTER 521
  • AAPM, Experience with California Law on Reporting CT Dose
  • Radiologist Compliance With California CT Dose Reporting Requirements: A Single-Center Review of Pediatric Chest CT
  • University of California Dose Optimization and Standardization Endeavor (UC-DOSE). Recommendations for compliance with California Senate Bill 1237 and related pending legislation.

The analysis of the different specifications allowed to obtain the following coverage between the minimal dose information and these specifications/guidelines:

Concepts mapping

The identified minimal dose information that should be collected by the dose management system and shared with third parties application, are divided into contextual information data and dose measurements data.

Contextual Information data:

Dose measurements data:

Artifacts Summary

Strategy

Following the recommendations of the WG-20, the resource Observation is profiled in order to describe the different dose information. 

Three Observations profiles are defined: 

• Dose Summary Observation profile
• Radiation Event Observation profile
• Indication Observation profile

The relationship between resources retained within the IG are described through the following relationships:

Draft evolution:

Dose Summary Observation Profile

Radiation Event Observation Profile

Indication Observation Profile

Pregnancy Status Profile

A profiling of pragnancy status was found in http://hl7.org/fhir/us/ecr/2018Sep/StructureDefinition-pregnancy-status.html ; from electronic Case Reporting (eCR) Implementation Guide: STU2 Ballot. However, the profiling is based on FHIR STU3 and R4. Even so, its structure is suitable for our use case:

Search parameters

The search parameters are important for consumers of the Dose Summary resource. 

For example, from the use case 1, the RIS needs to search in 

Annexes

Usage examples

Example 1: Search Dose Summaries

Description: search all the Dose summaries within the Dose Management.

Query: http://localhost:8080/fhir/Observation?code=73569-6

Example 2: View specific Dose Summary

Description: Access to the Dose summary resource

Query: http://localhost:8080/fhir/Observation/19

Response example:

{
  "resourceType": "Observation",
  "id": "19",
  "meta": {
    "versionId": "1",
    "lastUpdated": "2020-11-09T16:00:57.201+01:00",
    "source": "#PNgpiIToh4cxxhLW"
  },
  "identifier": [ {
    "value": "22"
  } ],
  "partOf": [ {
    "reference": "ImagingStudy/12"
  } ],
  "code": {
    "coding": [ {
      "system": "http://loinc.org",
      "code": "73569-6",
      "display": "Radiation exposure and protection information"
    } ]
  },
  "subject": {
    "reference": "Patient/20"
  },
  "effectiveDateTime": "2013-02-21T09:17:53+01:00",
  "device": {
    "reference": "Device/22"
  },
  "component": [ {
    "code": {
      "coding": [ {
        "system": "http://dicom.nema.org/resources/ontology/DCM",
        "code": "111636",
        "display": "Entrance Exposure at RP"
      } ]
    },
    "valueQuantity": {
      "value": 268.0,
      "unit": "mGy"
    }
  }, {
    "code": {
      "coding": [ {
        "system": "http://dicom.nema.org/resources/ontology/DCM",
        "code": "113722",
        "display": "Dose Area Product Total"
      } ]
    },
    "valueQuantity": {
      "value": 188.10000658035278,
      "unit": "dGy.cm2"
    }
  }, {
    "code": {
      "coding": [ {
        "system": "http://dicom.nema.org/resources/ontology/DCM",
        "code": "113726",
        "display": "Fluoro Dose Area Product Total"
      } ]
    },
    "valueQuantity": {
      "value": 34.800034046173096,
      "unit": "dGy.cm2"
    }
  }, {
    "code": {
      "coding": [ {
        "system": "http://dicom.nema.org/resources/ontology/DCM",
        "code": "113727",
        "display": "Acquisition Dose Area Product Total"
      } ]
    },
    "valueQuantity": {
      "value": 153.2999725341797,
      "unit": "dGy.cm2"
    }
  }, {
    "code": {
      "coding": [ {
        "system": "http://dicom.nema.org/resources/ontology/DCM",
        "code": "113730",
        "display": "Total Fluoro Time"
      } ]
    },
    "valueQuantity": {
      "value": 254,
      "unit": "s"
    }
  } ]
}

Example 3: Access Device dose summaries

Description: in order to make metrics on a device, a research by device on Dose summary should be permitted

Query example: http://localhost:8080/fhir/Observation?code=73569-6&device=22 

Example 4: Dose Summary of a patient through the last year

Description: Access to the dose summary of a patient during the last year.

Query example: http://localhost:8080/fhir/Observation?code=73569-6&patient=8&date=gt2019-01-01 

Example 5: Dose Summary related to the study

Description: Access to the dose summary based on the StudyInstanceUID

Query example: http://localhost:8080/fhir/Observation?code=73569-6&part-of=1232  

Recommendations for compliance with California Senate Bill 1237

One of the most complete analysis about the Senate Bill 1237 is the "Recommendations for compliance with California Senate Bill 1237 and related pending legislation", from the University of California Dose Optimization and Standardization Endeavor (UC-DOSE). The document provides recommendations on the dose data to be exposed in the imaging report. Here is an extract of this document:

The analysis of this document identifies some data from the Radiation Event level that need to be exposed in the report. This need to expose radiation event data was expressed in this IG by the designing of the Radiation Event Observation profile.

Compliance with Order of 22 September 2006, France

In order to check the compliance with France regulations, we can expose the analysis details of the most recent recommendations found: Presentation of the main radiation protection regulatory provisions applicable in medical and dental radiology (Guideline: 2016). We highlighted the different dose information found :

The found dose information that need to be reported are: the patient identifier, the performing physician, the perform date, the justification of the act (may be interpreted as the indications of the exam), indications about the used device, the DAP and the DLP.

Imaging Report specification, Finland

The analysed document is: Finnish Imaging Report specification, KanTa Imaging CDA R2 document structures (2013)

For the identification of the dose information, this specification reference a document from Finnish Radiation and Nuclear Safety Authority:  "Röntgentutkimuksesta potilaalle aiheutuvan säteilyaltistuksen määrittäminen" translated into "X-ray examination of the patient radiation exposure determination": https://www.julkari.fi/bitstream/handle/10024/125145/rontgensateily.pdf 

The imaging report specification identify a table with dose information to be reported:

Related JIRAs

PSS-1716 - Getting issue details... STATUS

PSS-1678 - Getting issue details... STATUS

References

1. DICOM, DICOM PS3.20: Imaging Reports using HL7 Clinical Document Architecture
2. DICOM, DICOM PS3.16: Content Mapping Resource
3. DICOM, X-Ray Radiation Dose SR IOD Templates
4. DICOM, CT Radiation Dose SR IOD Templates
5. DICOM, Radiopharmaceutical Radiation Dose SR IOD Templates
6. DICOM, TID 2008. Radiation Exposure and Protection Information
7. French Society of Radiology - SFR, Practical Guide for Interventional Radiology (Guideline - 2013)
8. French High Authority of Health - HAUS, Patient radiation protection and analysis of CPD practices and certification of healthcare establishments (Guideline - 2012)
9. French nuclear safety authority, Presentation of the main radiation protection regulatory provisions applicable in medical and dental radiology (Guideline: 2016)
10. French Minister of Health and Solidarity, Order of 22 September 2006 relating to the dosimetric information to be included in an act report using ionizing radiation, (Order - 2006)
11. Finnish Imaging Report specification, KanTa Imaging CDA R2 document structures (2013)
12. Finnish Radiation and Nuclear Safety Authority, Röntgentutkimuksesta potilaalle aiheutuvan säteilyaltistuksen määrittäminen (X-ray examination of the patient radiation exposure determination)
13. AAPM, Computed Tomography Dose Limit Reporting Guidelines for Section 3 – 115113
14. Senate Bill No. 1237, CHAPTER 521
15. AAPM, Experience with California Law on Reporting CT Dose
16. Radiologist Compliance With California CT Dose Reporting Requirements: A Single-Center Review of Pediatric Chest CT
17. University of California Dose Optimization and Standardization Endeavor (UC-DOSE). Recommendations for compliance with California Senate Bill 1237 and related pending legislation