28 March 2023

Medical physicists have developed a technique to accurately measure radiation dose using new magnetic resonance imaging (MRI) linac machines.

Coupling MRI machines with a linac accelerator allows clinicians to see the tumour or target area in real-time during treatment, and therefore deliver radiation more precisely to the active tumour.

But magnetic fields from the MRI component of the linac can affect the radiation distribution within patients says the Australian Radiation Protection and Nuclear Safety Agency’s (ARPANSA) Chief Medical Radiation Scientist Dr Ivan Williams.

‘The Australasian College of Physical Scientists and Engineers in Medicine position paper, which scientists at ARPANSA have co-authored, recommends how to measure radiation dose by accounting for interference from magnetic fields,’ Dr Williams said.

‘Being able to calculate and plan appropriate dose using this new technology is critical to the high-quality patient care.’

Each year, around 70,000 Australians will be treated with radiotherapy for cancer. ARPANSA seeks to ensure that all use of radiation in medical procedures is justified and safe.

‘This work leads on from ARPANSA’s development of a successful dose audit protocol for MRI linacs and is important to the promotion of dose accuracy’, said Dr Williams.

‘Patient safety is at the heart of this work which will help ensure accurate dose across the country and internationally.’

The paper was published 20 February in Physical and Engineering Sciences in Medicine.

You can read it here: ACPSEM position paper: dosimetry for magnetic resonance imaging linear accelerators

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