Thank you for your reply. Interesting information about fixation, it still seems to have impact on entire process. Good idea to bring the arms down and even ask patient to sit down just before CT. It may help the work at the future setup process. We also use indexing values in the fixation- middle tattoo mark should meet the measured value (measured at the CT) at the fixation.
The specific case I tried to explain was that when the patient is at the treatment couch and laser is at the indexed value, then middle tattoo mark is too cranially in comparison to laser. AlignRT shows +pitch, (as it should show) and LAT setup image shows that sternum is too cranially. What do we do? If we ask patient to go up or down, in my opinionm pitch remains the same. Gently press to the lower part of sternum helps a bit but not entirely. We will continue with this in practice and let us know what happens.