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Criticism of the 3%/3 mm γ metric
❑
The common 3%/3 mm γ analysis metric is
not sensitive enough
to
provide optimal results in IMRT/VMAT
commissioning
.
❑
Overreliance on the insensitive metric is
counterproductive
to quality
improvement and can lead to the sense of complacency among the clinical
physicists.
❑
Use of this metric also enables manufacturers to release products that may
not be validated with sufficient rigor
, hindering them from designing
error out of the system before commercial release.
❑
“adoption of more sensitive metrics/tighter tolerances enables continual
improvement of the accuracy
of radiation therapy dose delivery”
❑
Adoption of sensitive metrics and tighter tolerances fit the larger goal to
better standardize the methods and processes of commissioning and
product validation, with the ultimate goal to increase quality…
Nelms et al, Med Phys 2013.
Dublin 2018
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