Performance Test – Dose output

How much does the IQM signal change when the dose output is changed by 1% from 100MU to 101MU?

A 1% change in dose output results in a 1% change in IQM signal

Similar proportional changes have been achieved for field sizes of 5cm x 5cm, 10 cm x 10cm, 20cm x 20cm as well as dose output changes of 0.5%, 10% and 100%

Performance Test - Beam Placement/Position


How much does the IQM signal change when a 4cm x 4cm field is shifted 5mm off-axis?

Moving a beam by 5mm changes the IQM signal
by up to 2.2%.

Similar results have been achieved when applying the same change
at different beam locations and different shift directions.
Shifts of 3mm are also well detectable.

Performance Test - Intensity Map changes


How much does the IQM signal change when the intensity map of an IMRT beam is changed?

Changing the intensity map of an IMRT beam without changing the total MU
is detectable by IQM.

IQM is the only verification system capable of detecting these kind of deviations.