Three MRI radiotherapy guidelines were largely consistent but differed in scope

KEY POINTS

• The review compares the 2021 IPEM topical report, 2021 AAPM Task Group 284 report and 2023 NCS Report 36, with authors representing the organisations responsible for the three documents.
• IPEM and AAPM primarily address implementation and quality assurance of dedicated or dual-purpose MRI simulation, including equipment selection, installation, staffing, safety, workflow design, protocol optimization and imaging in treatment position.
• NCS Report 36 has a broader application range, covering diagnostic MRI used for radiotherapy, MRI simulation, MR-only planning and MR-Linac systems. It also provides basic MRI physics and step-by-step instructions for quality-assurance testing.
• Most core quality-control tests were included in all three reports, including signal-to-noise ratio, uniformity, artefacts, geometric fidelity, B0 homogeneity, couch positioning, data orientation and end-to-end testing.
• Resonance-frequency and radiofrequency-transmit-amplitude testing were omitted from IPEM, motion verification was specific to AAPM, synthetic computed tomography testing appeared only in NCS, and seven MR-Linac-specific tests were covered only by NCS.
• Geometric-fidelity recommendations were closely aligned: AAPM recommends errors below 1 mm within a 10 cm radius and below 2 mm within a 20 cm radius, while IPEM recommends 2 mm for most applications and 1 mm for stereotactic radiosurgery.
• Differences in quality-assurance frequency and tolerances were generally small and often reflected regional regulations or different radiology standards. The authors conclude that the documents should be used as complementary resources rather than competing guidelines.

CLINICAL TAKEAWAY

SOURCE

Medical Physics