Test purpose

Evaluate the error sensitivity of the IQM system.

Test method

15 VMAT plans (5 prostate, 5 breast and 5 Head & Neck) were evaluated. A variety of clinically relevant errors were introduced into a VMAT plan. Single segments were modified with single leaf bank errors of +1mm, dual leaf bank errors of 1mm and 2mm, uni-directional shifts of 1mm and 2mm as well as a MU increase of 2% and 5% in a single segment.

Test results

IQM was able to detect all 10 different errors introduced into the 15 VMAT plans.


IQM shows very good dosimetric properties and error detection sensitivity. IQM can potentially replace the 2D plan verification method.