Quality control and dosimetry for MRI-guided-radiotherapy

The developments in radiotherapy have always been focused on better imaging and more accurate delivery. Coming from external markers to EPID and CBCT, it is now possible to use MR-imaging for soft tissue visualization to compensate for anatomy variation during radiotherapy treatment. Two MR-guided-radiotherapy (MRgRT) systems have currently been clinically released: the Viewray MRIdian and the Elekta Unity. Several institutes in the Netherlands already installed an MRgRT system or are about to install one, and it is expected that these numbers will increase.  

From the limited existing literature it has already been shown that sub-millimeter accuracy can be achieved with these MRgRT systems. To assure high quality radiotherapy, this new technology should be supported with guidelines on acceptance, commissioning and quality control.  The aim of this subcommittee is to create a practical guideline for efficient and effective quality control and dosimetry that is in line with the existing guidelines and protocols. The report will focus on the linear accelerator part of the MRgRT system and will describe the required adaptations from conventional RT. Existing relevant literature is combined with the collective experience of the subcommittee members. Both clinically available MRgRT systems will be covered. Special attention will be given to the magnetic field effects on measurement equipment, QA tests and dosimetry as well as MRI safety.

The subcommittee had its first meeing on 11 February 2020.


Topics to be covered

  • Background and basics
  • Site preparation
  • Acceptance, commissioning and dosimetry
  • Clinicial implementation & workflow
  • Best practice, tips and tricks


Members of this NCS subcommittee

  • Daan Hoffmans - Amsterdam UMC
  • Miguel Palacios - Amsterdam UMC
  • Akos Gulyban - L’Institut Jules Bordet 
  • Jochem Kaas - RadboudUMC
  • Tomas Janssen - NKI
  • Martijn Kusters - RadboudUMC
  • Kathrin Surmann - Radiotherapiegroep 
  • Hendrik Piersma - SKF-RIF
  • Jochem Wolthaus - UMC Utrecht (chair, j.wolthaus-at-umcutrecht.nl)
  • Bram van Asselen - UMC Utrecht 
  • Rob Tijssen - Catharina Ziekenhuis
  • Thierry Gevaert - UZ Brussel
  • Jacco de Pooter - VSL (Representative of the NCS board)
  • Leon de Prez - VSL