Dose Course 2018_Flipping book

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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