How do you optimally set a patient up for breast radiation therapy if you don't have access to a breast board or wing board?

"Optimally" is a continuum and hard to define.

Without a breast board or wing board, a vac-lok bag might be your best bet. You can often move much of the "beans in the bag" superiorly in the bag, so that you can create something to support the patient's ipsilateral arm(s). Plus, moving the beans sup...

I like the vacloks as well. By being creative with moving the beans around, you can build up a great arm cradle and get a very reproducible setup, especially in whole breast treatment where margins are measured in centimeters and not millimeters.