Hi, We currently started treating Pelvic SBRT patients using AlignRT for monitoring and Bodyfix Bags.
We have treated a number of patients and on our first patient the VacBag went too far past the mid-coronal plane and did cause some issues with AlignRT so I would suggest keeping the VacBag relatively low laterally if possible. We do use Hexapod to position our patients and correcting for rotations after CBCT. What we have noticed is that while using the VacBag can be good for immobalisation, it limits the fine adjustments that can be made when using AlignRT alone particularly for rotations. I personally feel we would have less rotations on our CBCT if we had not used the Vacbags for these particular patients.
We are looking at the possibility of removing the bodyfix VacBags from our workflow for sites that do not necessarily require it.