Dear users,
I’m working on improving our treatment planning process by replacing CumulativeMetersetWeight from DICOM RT plan with Step Dose/Actual Value (Mu) from the Logfile. However, I’m facing challenges with discrepancies between Logfile data and RayStation restrictions. The problem arises because sometimes the difference between two step doses from the Logfile doesn’t align with the restrictions in RayStation, resulting in values that are sometimes lower and sometimes higher.
what is the best method to select data from Logfile to update DICOM RT plan? for example using relevant angle or selecting the optimal line from Logfile corresponding to the same ControlPointIndex as the DICOM RT plan?
Looking forward to your guidance.
Zahra
I think this would depend on what kind of delivery technique is involved.
If it’s a VMAT, then gantry angle is probably your best choice for determining which log lines are accumulated to a pair of control points. But for an IMRT, I think you would want to pick the log lines that have the closest match to the MLC positions for the even index control point (start) and odd index control point (end). Mapping the log files in to their equivalent RT Beams Treatment Record representation is essentially the same problem, and I think that’s a worthwhile feature for PyMedPhys. Any experience you gain in doing the above by hand would be very helpful in creating such a feature.
Thank you so much for your reply, yes, it’s VMAT and our treatment plan is RayStation. I decided to use the gantry angle but the problem is RayStation sometimes fails to calculate dose because of the some restrictions. for example, some times the difference between two step doses from the Logfile doesn’t align with the restrictions in RayStation.