Commissioning of an MR‐linac Elekta Unity
DOI:
https://doi.org/10.37004/sefm/2024.25.1.002Keywords:
commissioning, MR-linac, Unity, adaptive radiotherapyAbstract
The combination of a linear accelerator with a magnetic resonance has given rise to magnetic resonance image-guided radiotherapy systems, known as MR-linac. These systems take advantage of the magnetic resonance image to locate the tumor and the position of healthy organs and make it possible to adapt the treatment plan for each fraction, as well as to visualize the patient's anatomy during treatment, while irradiation is taking place. The combination of both devices adds a degree of complexity to the commissioning process. This work describes the measurements made during the commissioning of those corresponding to the linear accelerator, the magnetic resonance, and the combination of both devices. All measurement results met the established tolerances, and only an improvement in the accuracy of the MLC position was required. The performance tests of the system with IMRT treatments exceeded the gamma index 3%/3 mm and 5% background threshold with values above 95% while the measurement with ionization chamber differed by a maximum of 0.87% with respect to that calculated by the TPS.
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