Medical Physicists at Allegheny Health Network (AHN) compared the sensitivity of the IQM System to beam energy changes against 4 other conventional methods,
The team measured baseline data for a 6MV beam on an Elekta Versa HD with the five following methods:
- Beamscan 3D scanner with PTW Semiflex 3D ionization chamber (PTW)
- Daily QA3 (Sun Nuclear)
- IC Profiler (Sun Nuclear)
- Farmer Chamber in plastic water (PTW)
- IQM transmission detector (IRT Systems)
After the initial baseline measurements, the beam energy was adjusted by 0.5% and by 1% and then back to the baseline energy for a total of 4 sets of measurements.
Different analysis methods were employed for the different devices.
The investigation demonstrated that the different measurement methods required widely different tolerances to provide the same precision when checking the beam energy.
Further, the results indicate that
“The IQM device was approximately twice as sensitive as the other chamber methods.”