Standards — Irish DXA Society

Irish DXA Society Standards

Definitions (HIQA)

Standard: A repeatable, consistent, agreed and documented way of performing an activity. A standard describes the high-level outcome required to contribute to quality and safety.

Authority: The Health Information and Quality Authority (HIQA).

Agency: The Environmental Protection Agency (EPA/ORM).

Clinical Responsibility: Responsibility of a practitioner for individual medical exposures.

Medical Exposure: Exposure incurred by patients or asymptomatic individuals as part of their own medical or dental diagnosis or treatment, and intended to benefit their health, as well as exposure incurred by carers and comforters and by volunteers in medical or biomedical research.

Minister: The Minister for Health.

Practical aspects of a medical radiological exposure (SI 256) for DXA scanning: The physical conduct of DXA scanning and any supporting aspects of DXA performed by an individual registered or recognised by:

 The Minister for Health
 NMBI (Nursing and Midwifery Board of Ireland)
 Radiographers Registration Board
 Medical Council

Practitioner (SI 256:5): A Person who takes clinical responsibility for an individual medical exposure/Report/Interpretation with respect to DXA:

 Registered medical practitioner (Irish Medical Council);
 Registered Radiographer (CORU)

Referrer (SI 256:4): A person entitled to refer an individual for medical radiological procedures to a practitioner:

 Registered nurse referrer (Nursing and Midwifery board of Ireland);
 Registered medical practitioner (Irish Medical Council);
 Registered radiographer (CORU).

Official Positions: Accepted recommendations for standards or guidelines related to densitometry following a robust scientific process of the International Society for Clinical Densitometry (ISCD) become the Official Positions of the ISCD.

Reference: EM Lewiecki. Osteoporos Int. 2004: 779-784. PMID: 15278247.

Standards

All persons performing or interpreting DXA scans should meet national legislative and regulatory requirements to perform and/or interpret a DXA scan.

Under Irish Legislation: All persons performing or interpreting DXA scans should have the knowledge, skills and competencies to perform and/or interpret a DXA scan.

The standards are intended to encourage learning and excellence in performance to ensure patient safety and quality care.

They are not intended to be a barrier to training, development or performance.

DXA standards are a guide to best practices backed up by international and national evidence-based positions. The acceptable standards are based on research, evidence and the consensus of experts.

Our standards have been adopted from the International Society for Clinical Densitometry Best Practice Paper and adapted to meet Irish national requirements and regulations – see standards.

Knowledge: The theoretical understanding of DXA technology, imaging, analysis and interpretation.

Examples: Patient anatomy and positioning, radiation safety.

Sources: ISCD Courses, Irish DXA courses, Textbooks, Peer-Reviewed Journal Articles, Manufacturer’s training manual and other resources.

Skills: Specific abilities to perform the practical aspects of DXA to recommended standards including scanning, analysis and reporting of scans.

Examples: Patient communication. Patient imaging. Interpretation and analysis of scans.

Sources: Practical training sessions with qualified experts and DXA workshops, including new techniques and development of practical skills.

Competency: is a complex multidimensional phenomenon, defined as the ability to practice safely and effectively. It is the attainment of knowledge, practical skills, good communication, professional and ethical values.

Examples: Certification or Accreditation by a recognised national or international training body such as The International Society for Clinical Densitometry, or The Irish DXA Society. Demonstration of the knowledge and skills required to perform and/or interpret DXA scans, including appropriate referrals, scan acquisition, analysis and interpretation.

The Irish DXA Society endorses the Official Positions of the ISCD.

These are available on the ISCD website.

Best Practice Minimum Standards for DXA Scan Acquisition and Analysis

1.1. At least one practitioner/personnel delegated the practical aspects (preferably all) has a valid certification in bone densitometry.

1.2. Each DXA practitioner/personnel delegated the practical aspects has access to the manufacturer’s manual of technical standards and applies these standards for BMD measurement.

1.3. Each DXA facility has detailed standard operating procedures for DXA performance that are updated when appropriate and available for review by all key personnel.

1.4. The DXA facility must comply with all applicable legislative and regulatory radiation safety requirements. Locations require licencing/registration with the E.P.A.

1.5. Spine phantom BMD measurement is performed at least once weekly to document the stability of DXA performance over time. BMD values must be maintained within a tolerance of ±1.5%, with a defined ongoing monitoring plan that defines a correction approach when the tolerance has been exceeded.

1.6. Each DXA practitioner/personnel delegated the practical aspects has performed in vivo precision assessment according to standard methods and the facility LSC has been calculated for each anatomical region of interest: Spine, Proximal femur, forearm, whole body.

1.7. The LSC for each DXA operator should not exceed 5.3% for the lumbar spine, 5.0% for the total proximal femur, and forearm (TBD: to be determined), and whole body (TBD).

Best Practice Minimum Standards for DXA Scan Interpretation and Reporting

2.1. At least 1 interpreting DXA practitioner (preferably all) has a valid certification in bone densitometry.

2.2. The DXA manufacturer and model are noted on the report.

2.3. The DXA report includes a statement regarding scan factors that may adversely affect acquisition/analysis quality and artifacts/confounders, if present.

2.4. The DXA report identifies the skeletal site, region of interest, and body side for each technically valid BMD measurement.

2.5. There is a single diagnosis reported for each patient, not a different diagnosis for each skeletal site measured, including the lumbar spine.

2.6. A fracture risk assessment tool is used appropriately.

2.7. All follow-up DXA scans should be performed on the same machine at the same facility whenever possible for monitoring changes in BMD to ensure comparability with their baseline or serial scans.

2.8. When reporting differences in BMD with serial measurements, only those changes that meet or exceed the LSC are reported as a change.

2.9. In the absence of a valid cross-calibration study, DXA studies from different centres or manufacturers should not be compared for monitoring purposes. However, when exceptional circumstances occur, a quality scan may serve as a new baseline for monitoring purposes.

Reference: EM Lewiecki. J Clinical Densitometry 2016; 19(2): 127-40. PMID: 27020004.

Basic Training

The society recommends all personnel involved in the performance or interpretation of DXA should

Complete a recognised radiation safety course and abide by national legislative/regulatory requirements.
Complete certification for performing, analysing and reporting on DXA scans.
Undertake and record their first 100 scans for each anatomic site under supervision:
- Hip
- Spine
- Forearm
Complete mandatory requirements for relevant C.P.D.
Work to local recommended standard operating procedures.
Complete manufacturer specific equipment training.
Undertake national and international DXA training courses as recommended by the society.
Understand the importance of clinical audit, and undertake self-audit related to their DXA practice.
Effective communication pathways should be developed and utilised when appropriate between all personnel involved in DXA.

Advanced Training

The society recommends all personnel involved in the performance or interpretation of the following advanced DXA scanning procedures:

Vertebral Fracture Assessment (VFA) scanning
Whole Body scanning
Paediatric scanning

Should

Have completed all basic training requirements;
Have a valid current recognised certification in bone densitometry;
Complete national or international advanced course in the relevant DXA procedures;
Complete manufacturer-specific training in relevant advanced DXA technology, technique and interpretation.
Complete practical training in advanced DXA scans as recommended by the society.
Undertake and record their first 100 scans for each anatomic site under supervision:
- LVA
- Whole Body
- Pediatric scans
Paediatric scans should not be performed by people who are not familiar with performing or interpreting these scans, particularly those <16 years.
Complex paediatric scans should be referred to a recognised national centre.

Appendix 1: DXA Terminology and ISCD Definitions

BMD: Bone Mineral Density

DXA: Dual-energy X-ray Absorptiometry

ISCD: International Society for Clinical Densitometry

LSC: Least Significant Change

VFA: Vertebral Fracture Assessment

Note: Some Terminology/Professional Titles used by The International Society for Clinical Densitometry terminology differ:

Technologist: Professionals who perform DXA scans

Clinician: Professionals who report/interpret DXA scans

Scientist: Professionals who perform and/or interpret scans for non-clinical or research purposes.

In practice, these roles may overlap so some professionals may perform more than 1 role.

Last Update 3rd Sept 2021.