Question
What to do when the Gamma analysis is not working correctly with myQA Accept 9.0 and 9.1 when imported DICOM RTDose data is used?
Answer
In cases where different detectors are being used to compare data with the Gamma analysis functionality of myQA Accept 9.0 and 9.1, it can be that the results are not correct. Example:
This bug will be fixed with myQA Accept 9.2.
Workaround
Step 1
The issue is mainly due to an inconsistency of device turn angle between the comparison curves. The device turn angle tag of RTDose imported data can be changed by RTDose.xml in the following Accept folder. Please open with an editor:
C:\Program Files (x86)\IBA Dosimetry\myQA Accept\DeviceDescriptionOPA7\RTDose.xml
Step 2
RTDose.xml has a part which defines the device turn angle info, including three coordinates. Example:
<DefaultRotations>0 0 -90.0</DefaultRotations>
Please refer to the following table:
| Value of <DefaultRotations> | 3D Device View after DICOM RTDose import (please see always the small coordinate system on the images) |
| 0 0 -90.0 | |
| 0 0 90.0 | |
| 0 0 0.0 | |
| 0 0 180.0 |
Note: The "Device turn angle" information in the "Header information..." dialogue will still always show 0°:
Step 3
By updating RTDose.xml in accordance with the angle tag of the comparison data (e.g. chamber measurement), the Gamma analysis can be performed normally, also with DICOM RTDose imported data.