J. zu Münster
we use the 3 mm/degree tolerances as well. It works for all patients with very rare exceptions. We also don’t widen the tolerances. Turning off the beam hold might occur in very rare circumstances, where the Gantry Position blocking an Align RT camera might cause a “false” beamhold.
After having similar starting problems as you mentioned, we started to implement a “training appointment” before the planing CT. At that seperate appointment we position the patient on our treatment board and show how we excpect him to breathe and how he can train this at home. This helped a lot to better the quality of our planing CT’s by achieving a higher distance between respiratory center position and deep inspiration height and having less nervous patients who can follow the commands way better.
This also enabled us to filter better for patients that are unsuited for DIBH treatment, if they are unable to achieve sufficent inspiration lenghts/durations or too small differences between respiratory center position and DIBH for a real treatment benefit.
Our ROIs are L-shaped and include the whole treated brest, front and side, excluding Arm/Axilla, with a connected stripe below both breast across the body. After our current experiences it is vital for the ROI to function properly to not include the other breast if not also treated.