A New Era - MR-linacs
QA when treating with a MR-linac!
MR-linacs has been clinically available for a few years now and the clinical experience is improving every day. It is impressive what possibilities are made available with this new technology but there are also new risks involved with radiation treatments in very intense magnetic fields. These challenges are something everyone in the process has to take into account.
ScandiDos cooperated with UMC in Utrecht and came out with the pre-treatment verification system Delta4 Phantom+ MR a year ago to perform high quality PT-verification of the radiation therapy in high magnetic fields. The goal was to make the Delta4 Phantom+ MR as accurate and reliable as the Delta4 Phantom+, a product used in more than 45 countries world wide.
The patent concept of the Delta4 Phantom+ detector arrays and the unique dose per pulse measurement did not have to be changed for the Delta4 Phantom+ MR, it is a perfect concept for the MR-field. The detector configuration is even more important in the MR-field when QA must not rely on interpolations but rather real measurements in all points during the entire treatment delivery. This is unique and an important reason why the Delta4 Phantom+ MR provides outstanding accuracy. Another benefit with the two crossing arrays is that they do not create “Faraday-cage issues”.
The Delta4 Phantom+ MR can be cross-calibrated against an ionization chamber that is inserted into the phantom, but the chamber is not required to receive absolute dose during measurements. The diode arrays provide absolute dose distribution directly.
Today Delta4 Phantom+ MR is used on all continents of the world, both on UNITY and MRIDIAN, and users are very pleased with the reliable and accurate measurement solution.