TY - JOUR
T1 - Acceptance procedure for the linear accelerator component of the 1.5 T MRI-linac
AU - Woodings, Simon J.
AU - de Vries, J. H.Wilfred
AU - Kok, Jan M.G.
AU - Hackett, Sara L.
AU - van Asselen, Bram
AU - Bluemink, Johanna J.
AU - van Zijp, Helena M.
AU - van Soest, Theo L.
AU - Roberts, David A.
AU - Lagendijk, Jan J.W.
AU - Raaymakers, Bas W.
AU - Wolthaus, Jochem W.H.
N1 - Funding Information:
The authors thank the support of the Dutch Cancer Society for this work. Each of the authors has made a substantial contribution to this work in concept, design, data acquisition, analysis and/or interpretation. Each of the authors has contributed to revising the work and has approved the final version to be published.
Publisher Copyright:
© 2020 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals LLC on behalf of American Association of Physicists in Medicine
PY - 2021/8
Y1 - 2021/8
N2 - Purpose: To develop and implement an acceptance procedure for the new Elekta Unity 1.5 T MRI-linac. Methods: Tests were adopted and, where necessary adapted, from AAPM TG106 and TG142, IEC 60976 and NCS 9 and NCS 22 guidelines. Adaptations were necessary because of the atypical maximum field size (57.4 × 22 cm), FFF beam, the non-rotating collimator, the absence of a light field, the presence of the 1.5 T magnetic field, restricted access to equipment within the bore, fixed vertical and lateral table position, and the need for MR image to MV treatment alignment. The performance specifications were set for stereotactic body radiotherapy (SBRT). Results: The new procedure was performed similarly to that of a conventional kilovoltage x-ray (kV) image guided radiation therapy (IGRT) linac. Results were acquired for the first Unity system. Conclusions: A comprehensive set of tests was developed, described and implemented for the MRI-linac. The MRI-linac met safety requirements for patients and operators. The system delivered radiation very accurately with, for example a gantry rotation locus of isocenter of radius 0.38 mm and an average MLC absolute positional error of 0.29 mm, consistent with use for SBRT. Specifications for clinical introduction were met.
AB - Purpose: To develop and implement an acceptance procedure for the new Elekta Unity 1.5 T MRI-linac. Methods: Tests were adopted and, where necessary adapted, from AAPM TG106 and TG142, IEC 60976 and NCS 9 and NCS 22 guidelines. Adaptations were necessary because of the atypical maximum field size (57.4 × 22 cm), FFF beam, the non-rotating collimator, the absence of a light field, the presence of the 1.5 T magnetic field, restricted access to equipment within the bore, fixed vertical and lateral table position, and the need for MR image to MV treatment alignment. The performance specifications were set for stereotactic body radiotherapy (SBRT). Results: The new procedure was performed similarly to that of a conventional kilovoltage x-ray (kV) image guided radiation therapy (IGRT) linac. Results were acquired for the first Unity system. Conclusions: A comprehensive set of tests was developed, described and implemented for the MRI-linac. The MRI-linac met safety requirements for patients and operators. The system delivered radiation very accurately with, for example a gantry rotation locus of isocenter of radius 0.38 mm and an average MLC absolute positional error of 0.29 mm, consistent with use for SBRT. Specifications for clinical introduction were met.
KW - acceptance tests
KW - dosimetry
KW - magnetic field
KW - MRI-linac
KW - Unity
UR - http://www.scopus.com/inward/record.url?scp=85110926085&partnerID=8YFLogxK
U2 - 10.1002/acm2.13068
DO - 10.1002/acm2.13068
M3 - Article
C2 - 34275176
AN - SCOPUS:85110926085
SN - 1526-9914
VL - 22
SP - 45
EP - 59
JO - Journal of applied clinical medical physics
JF - Journal of applied clinical medical physics
IS - 8
ER -