- Title
- Evaluation of the truebeam machine performance check (MPC) geometric checks for daily IGRT geometric accuracy quality assurance
- Creator
- Barnes, Michael P.; Greer, Peter B.
- Relation
- Journal of Applied Clinical Medical Physics Vol. 18, Issue 3, p. 200-206
- Publisher Link
- http://dx.doi.org/10.1002/acm2.12064
- Publisher
- John Wiley & Sons
- Resource Type
- journal article
- Date
- 2017
- Description
- Machine Performance Check (MPC) is an automated and integrated image-based tool for verification of beam and geometric performance of the TrueBeam linac. The aims of the study were to evaluate the performance of the MPC geometric tests relevant to OBI/CBCT IGRT geometric accuracy. This included evaluation of the MPC isocenter and couch tests. Evaluation was performed by comparing MPC to QA tests performed routinely in the department over a 4-month period. The MPC isocenter tests were compared against an in-house developed Winston–Lutz test and the couch compared against routine mechanical QA type procedures. In all cases the results from the routine QA procedure was presented in a form directly comparable to MPC to allow a like-to-like comparison. The sensitivity of MPC was also tested by deliberately miscalibrating the appropriate linac parameter. The MPC isocenter size and MPC kV imager offset were found to agree with Winston–Lutz to within 0.2 mm and 0.22 mm, respectively. The MPC couch tests agreed with routine QA to within 0.12 mm and 0.15°. The MPC isocenter size and kV imager offset parameters were found to be affected by a change in beam focal spot position with the kV imager offset more sensitive. The MPC couch tests were all unaffected by an offset in the couch calibration but the three axes that utilized two point calibrations were sensitive to a miscalibration of the size in the span of the calibration. All MPC tests were unaffected by a deliberate misalignment of the MPC phantom and roll of the order of one degree.
- Subject
- linac quality assurance; machine performance check (MPC)
- Identifier
- http://hdl.handle.net/1959.13/1399649
- Identifier
- uon:34651
- Identifier
- ISSN:1526-9914
- Rights
- © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
- Language
- eng
- Full Text
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