News Archive

29 January 2024
Report on AAPM Quality Measures Roundtable Discussion

Thomas L. Morgan, HPS Medical Health Physics Section President

The American Association of Physicists in Medicine (AAPM) held the Quality Measures Roundtable discussion 23 October 2023. I participated as a representative of the Health Physics Society (HPS).

Background

Recently, the Centers for Medicare and Medicaid Services (CMS) proposed a new quality metric as part of the 2024 Inpatient Prospective Payment System Rule. Known as the "Excessive Radiation Dose or Inadequate Image Quality for Diagnostic Computed Tomography in Adults" rule, this measure provides a standardized method for monitoring the performance of diagnostic CT to discourage unnecessarily high radiation doses, a risk factor for cancer, while preserving image quality. It is expressed as a percentage of CT exams that are out-of-range based on having either excessive radiation dose or inadequate image quality relative to evidence-based thresholds based on the clinical indication for the exam.

The American College of Radiology responded with detailed comments, many of which questioned if the current state of the art of medical imaging informatics and a lack of well-defined and accepted definition of "excessive dose" could support this new rule.

This roundtable brought together a broad spectrum of organizational stakeholders with a vested interest in the quality of medical imaging practice. The goal of this roundtable was to form a broad consensus about how the quality, safety, and consistency of medical CT imaging can be assured.

Over the span of some eight hours, individuals from 19 organizations presented thoughts on three questions:

  • Where are we now (current state)?
  • What is needed?
  • How do we get there?

A draft of a consensus document has been prepared and circulated for comment.

HPS Perspective

To avoid unnecessary exposure and risk to patients, there are three main concepts to consider:

  • Justification
  • Optimization
  • Dose limits

The HPS has published several positions relevant to diagnostic medical imaging:

  • CT scanning – Computed tomography (CT) screening exams should only be performed if prescribed by a qualified health care provider.
  • Radiation exposure of public – No person should be intentionally exposed to ionizing radiation without his or her knowledge.
  • Risk – The HPS has concluded that estimates of health risk should be limited to individuals receiving a dose of 50 mSv in one year or a lifetime dose of 100 mSv above that received from natural sources.
  • Risk assessment –
    • Risk assessments should be consistent, of high technical quality, unbiased, and based on sound, objective science.
    • Risk assessments should employ the best available scientific and/or technical data.
    • Risk assessments should include consideration of uncertainties.

Takeaways From Roundtable

From the perspective of a radiation protection professional, the following statements from the consensus documents are relevant:

Question

Statements

Quality measures:
Current state
  • Medical imaging is indispensable for patient care.
  • Imaging professionals have a responsibility to minimize risk to patients, including those associated with medical imaging.
  • Radiation dose is an imperfect and limited surrogate to assess the quality of an imaging practice as in the moniker of "low-dose" as a sole measure of quality.
  • Dose and associated risk are both over-represented and misunderstood by patients and the public, whereas image quality in a risk-benefit comparison is underappreciated.
  • Professional organizations and agencies provide both unique as well as overlapping strengths which should be coordinated to advance the cause of quality assurance in imaging.
  • There is a lack of and incentives for improvement initiatives.

Quality measures:
What are the needs?
  • An operational approach for metrics that have clear goals, and are transparent, accessible, efficient, and acceptable by all users.
  • An approach based on sound scientific methods vetted through rigors of evidence-based and peer-review processes and scientific impartialities.
  • Being based on the broad consensus of scientists and practitioners (within and outside of the imaging profession), industry, regulators, and patients.
  • An effective education for all relevant parties involved.
  • Taking an "on offense" (as opposed to "on defense") strategy – moving forward – constructing a program based on advocacy of advancement through informed use as opposed to being derived solely or largely from proclamations of avoiding resultant harm.
  • Seeking to define a "floor" on performance, differentiating between being aspirational vs. meeting minimum standards. This involves a culture of quality to overcome the inertia of positive bias.

Quality measures:
How do we get there?
  • Maintain a multipronged and continuous engagement (design, validation, application, standardization, regulation, implementation, maintenance, team engagement).
  • Establish clear standards with validation, transparency, and independent processes defined by those responsible for imaging.
  • Inclusivity by involvement with relevant specialties and professions for performance of medical imaging.
  • Include patient perspectives, recognizing patient agency in the process.
  • Establish metrics of success.

 

HPS Engagement

Much of this effort is beyond the scope of radiation protection, per se. Radiation protection professionals are not directly responsible for medical imaging quality, do not participate in decision making with respect to the appropriateness of medical imaging procedures, and do not set techniques for CT scanners.

However, we are experts in applying the three pillars of radiation protection (justification, optimization, and dose limits). Hence, we have a place at the table. The HPS should remain engaged in this effort by monitoring its progress and providing technical knowledge, expertise, and support where appropriate.

Recommendations

  1. Educate HPS members on this new rule and efforts by various stakeholders to respond.
  2. Monitor this effort. Suggest alerting the Medical Health Physics Section, Intersociety Relations Committee, and Government Relations Committee about this effort. Section and committee members should reach out to other stakeholders to offer to participate in this effort.
  3. Stand ready to appoint appropriate HPS members with appropriate knowledge, experience, and training to joint task forces when requested.
  4. Consider drafting additional position statement(s) supporting this initiative.
  5. Consider soliciting abstracts on this effort for the annual HPS meeting.

In-person attendees at the AAPM Quality Measures Roundtable
Photo courtesy of AAPM