Improving Health Through Medical Physics

IMAGING PRACTICE ACCREDITATION SUBCOMMITTEE REPORT

Tyler Fisher, MS | Costa Mesa, CA

AAPM Newsletter — Volume 43 No. 5 — September | October 2018

Guidance and Clarification of the Joint Commission Fluoroscopy Standards

On June 25, the Joint Commission released the Prepublication Requirement for accredited organizations providing fluoroscopy. The standards will go into effect on January 1, 2019. The Joint Commission received a number of comments during the preceding comment period and modified the standards significantly to arrive at the current standards.

Many physicists, however, still have questions and have been asking for clarification regarding the new standards. During the Imaging Practice Accreditation Subcommittee meeting that took place in Nashville at the AAPM Annual Meeting, we were able to speak with Andrea Browne, Diagnostic Medical Physicist at the Joint Commission. She provided significant guidance and clarification regarding the intent and expectation of the Joint Commission regarding the new fluoroscopy standards.

The standards have been written with input from numerous stakeholders, including physician, technologist, and manufacturer representatives in addition to the input of the AAPM. The standards apply to all diagnostic uses of fluoroscopy, including mini C-Arms, standard C-Arms, traditional R/F equipment, and advanced interventional and cardiac cath equipment. The only exempted systems are those used for radiation therapy treatment planning or delivery (OBI).

A key point is that any Elements of Performance that are considered annual, specifically the medical physics testing requirements and the documentation of training of individuals that perform fluoroscopy, those standards must be met no later than December 31, 2019. For those other elements of performance, specifically designating a radiation safety officer to oversee diagnostic imaging, recording dose metrics in a retrievable format, identifying dose thresholds that require follow-up, and review of incidents requiring follow-up, those processes must be in place starting January 1, 2019.

Regarding the specific testing requirements of the annual medical physics performance evaluation, the following clarifications are our committee's interpretation of our discussion with Andrea. Comments in bold are considered minimal standards and any discussion thereafter represents an encouraged, best practice.

  • Beam Alignment and Collimation
    • This evaluation should consist of a numerical result. Some states have this requirement, with pass/fail criteria, in place already, but others do not. For those states that do not have such limits, the following guidance from the FDA should be applied: "Neither the length nor the width of the x-ray field in the plane of the image receptor shall exceed that of the visible area of the image receptor by more than 3 percent of the SID. The sum of the excess length and the excess width shall be no greater than 4 percent of the SID."
  • Tube Potential/kilovolt Peak Accuracy and Beam Filtration (Half-Value Layer)
    • There should be more than one kVp station recorded for kVp accuracy and HVL. For those using solid state dosimeters, these values are available for every measurement, so why not include that data. For those without solid state detectors, a representative sample over the range of clinical settings and the maximum rate should be performed. Results should be compared to state and/or FDA limits.
  • High-Contrast Resolution
    • This must include a numerical result for resolution, not simply a pass/fail. Different magnification modes should also be indicated and significant discrepancies from baseline testing should be noted.
  • Low-Contrast Resolution
    • This must include a numerical value, not simply a pass-fail. There are many phantoms available that provide this evaluation.
  • Maximum Exposure-Rate in All Imaging Modes
    • This evaluation must include at least the Maximum Exposure setting in fluoroscopic mode and in a cine mode. For advanced systems (cardiac cath labs, angiography, interventional), best practice would include results for low, normal, and high fluoroscopy modes, a digital acquisition setting, and a DSA setting. The intent is not to require every frame rate at every dose setting, but to help users of fluoroscopy equipment to understand the differences between imaging modes.
  • Displayed Air-Kerma Rate and Cumulative Air-Kerma Accuracy
    • The Joint Commission clarified that it would be acceptable to infer air-kerma rate accuracy from cumulative air-kerma accuracy. This element of performance will also be interpreted to include kerma area product accuracy if it is the only metric available. The Joint Commission does not specify a limit for accuracy, but the FDA recommended limit is ±35%.

For advanced systems capable of a 3D acquisition, the Joint Commission does not require any testing beyond what may be required by state regulation. For systems that may not be capable of performing a certain test (cumulative air-kerma), the physicist should document in the annual evaluation that this test is not available on the unit.

The Joint Commission included ongoing, annual education requirements for all individuals who perform fluoroscopy and specifically made a point to include physicians in that element of performance because they found a lack of awareness among some physicians to how they can best implement low doses. This element of performance, however, gives significant discretion to the facility as to how best to achieve the education. A surveyor will expect to see a written policy that states that education will be performed, that education will include radiation dose optimization techniques and safe operating procedures for the specific equipment, and documentation that all individuals have received the training. Online modules, staff meetings, or a daily huddle may be appropriate venues to receive this education.

The element of performance that requires cumulative air-kerma or kerma-area product be documented in a retrievable format does not require the use of dose monitoring software. A facility may use a paper log. The Joint Commission will want to see a written policy that states how this element of performance will be performed and then to verify that the facility does it as they say. For most facilities, fluoroscopy time is already being recorded, so the documentation of the more meaningful dose metrics should not be burdensome. Again, this element of performance applies to all fluoroscopy systems, including C-Arms and Mini C-Arms.

The final elements of performance require the facility to establish dose thresholds that, when exceeded, trigger further review that may include patient follow-up as well as a facility review of the incident. During the Annual Meeting, some suggested dose thresholds were 3 Gy for Peak Skin Dose (not displayed on most systems), 5 Gy for reference air-kerma, 500 Gy-cm2 for kerma-area product, or 60 minutes of fluoro time.

Finally, the Joint Commission emphasized that, if you have questions regarding the standards, especially during an inspection, to please call the Standards Interpretation Hotline and you will be able to speak to an expert and they will provide clarification to you and/or the surveyor regarding the standards.


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