Question
How can I avoid instability issues with myQA Daily?
Answer
Ionization chambers need a minimal amount of pre-irradiation to reach a stable response and their maximum measurement accuracy.
When using the myQA Daily device with radiation fields of less than 100 MU and less than 1 Gy dose to the ionization chamber array, a minimum amount of pre-irradiation of 0.25 Gy (field size: 25 cm × 25 cm).
If the dose of the irradiation is higher than or equal to 100 MU and the dose to the ionization chamber array is higher than or equal to 1 Gy, no pre-irradiation is necessary.
For simplifying the procedure, it is recommended to pre-irradiate with at least 500 MU during the LINAC's warm up phase in the morning.