Planning when the patient is upright

Weaker sourcing than the rest of this set. One peer-reviewed study, and the rest from the manufacturer's own material. Treat the specifics as unconfirmed until a planner who has worked upright corrects them.

The premise is an inversion. Instead of rotating a twenty-to-hundred-tonne gantry around a still patient, the beam is held fixed and the patient is rotated. The stated reason is mass: the patient is the lighter object.

What that costs a write-up. "Gantry 180°" means the source is behind the patient only because a supine patient and a moving gantry were assumed. Here the number that changes is the patient's own rotation. This is the couch-angle problem taken to its limit — state the frame first, or the angles refer to nothing.

Arm position is a planning variable. Arms up, down or behind changes what the beam can reach, so it belongs in the setup section of a write-up rather than being left to the therapist. An upright breast plan turns on it.

The planning CT is upright too. Anatomy is imaged under gravity, which is not the anatomy of a supine scan. Lung, breast and abdominal geometry all move. A dose comparison against a supine plan of the same patient is comparing two anatomies, not two plans.

There is no single planning system to name. The platform is built around somebody else's fixed beam, photon or particle, so the console is not determined by the machine. Say which one you used.