Michael Tallhamer, MSC, DABR
For large breasts you can CT the patient as you feel is best suited for treatment and then during import create two separate ROIs. For large breasts the first ROI can be the ROI without the pendulous portion of the breast included but include over midline grabbing the clavicular heads and the medial aspect of the contralateral breast for extra features for setup. The second can be smaller and more like the typical ROI including the breast tissue.
During setup you can setup using the first ROI to get the chestwall and general anatomy in the proper location then switch to the second ROI. When you switch to the second ROI you will most likely see a shift in the position due to the effects of the pendulous portion of the breast but now you move the breast to the ROI instead of the whole patient to the ROI. This allows you to do both patient positioning and setup as well as ensure the breast is in the field as intended each day. You can easily swap between ROIs in the software to make sure the breast stays stable during delivery. This has worked well for us when the patient isn’t a candidate for prone breast treatment.