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Calibration of TPS - Australia
The incident was discovered in 2006 when an
independent measure of machine output,
external
to the linear accelerator quality assurance
process,
was performed to implement some new
quality assurance software.
These measurements highlighted that there was
an
under-dosing of 5%
when they used data from
one of the linacs.
Further investigation at the time of the
detection of this anomaly was able to trace back
to the TPS beam calibration ratio as the likely
cause of the
consistent 5% dose discrepancy.
It involved 869 patients between 2004 and 2006.
Warsaw 2017
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