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Title: Poster — Thur Eve — 49: Unexpected Output Drops: Pitted Blackholes in Tungsten

Journal Article · · Medical Physics
DOI:https://doi.org/10.1118/1.4894909· OSTI ID:22407671
;  [1]
  1. Tom Baker Cancer Centre, Calgary AB (Canada)

During the daily measurement of radiation output of a 6 MV beam on a Varian Trilogy Linear Accelerator the output dropped below 2% and initiated a call to action by physics to determine the cause. Over the course of weeks the cause of the issue was diagnosed to be a defect in the target, resulting in a drop in output and an asymmetry of the beam. Steps were taken to return the machine to clinical service while parts were on order while ensuring the safety of patient treatment. The machine target was replaced and the machine continues to operate as expected. A drop in output is usually a rarity and a defect in the target is possibly more rare. This experience demonstrated the importance of routine QC measurement, recording and analyzing daily output and symmetry values. In addition, this event showcased the importance of a multi-disciplinary approach in a high-pressure situation to effectively troubleshoot unique events to ensure consistence, safety patient treatment.

OSTI ID:
22407671
Journal Information:
Medical Physics, Vol. 41, Issue 8; Other Information: (c) 2014 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-2405
Country of Publication:
United States
Language:
English