Forums › SGRT – Best Practice › Optimal ROI in FB setup to minimize displacement between vertebra and sternum › Reply To: Optimal ROI in FB setup to minimize displacement between vertebra and sternum
We do not use an inverse-T ROI, our ROI for both Free Breathing and DIBH breast patients covers the affected breast but also comes quite across the midline (sternum). I agree with Annika, with the larger ROI the system has a better picture of any pitch.
In regards to setting table height, at our centre we decided against this. We treat our breast patients on an inclined breast board and allow a 5mm tolerance in where they are longitudinally on the board. If a table height was set then in this case, it would influence the depth of the breath hold. In addition, the nice thing about always using 2 surfaces that were acquired on the same day (DICOM from CT), is that it makes the set up more robust even when breast swelling occurs. This would not be the case if the table height was set as a surrogate for free breathing surface.
the only other suggestion I could make is that if there is a vertebral/sternal mismatch then to observe the patient breathing in. It could be possible that in an attempt to reach the breath hold she has lifted her back.
Hopefully this is helpful,