MTWL Test

[eli_furhang]

Hi,
For a 5-bb phantom (VisionRT):

1. Do I obtain images for each of the BBs, or do I deliver them as control points with Field-in-Field? In other words, do I have 1 image per gantry/coll/table combination, or 5 images per gantry/coll/table combination.

2. Is FS = 10x10 okay?

3. the bb offset directions (left/up,in): are these done when
   a. For left & in: Looking down at the phantom (“Gantry @ 0”)
   b. For up/down: Looking at the side of the phantom (“Gantry @ 90”)

Thank you,
Eli

[jkerns]

1. 1 image per gantry/coll/couch combo. You’ll need to generate an image with a field centered around each bb like so the attached. Multi-BB, single field (MPC-like) is not yet supported.
2. The fields should follow the guidelines here: https://pylinac.readthedocs.io/en/latest/winston_lutz_multi.html#image-acquisition
3. The offsets are from the perspective of standing at the foot of the couch, irrespective of gantry angle: https://pylinac.readthedocs.io/en/latest/winston_lutz.html#coordinate-space

[eli_furhang]

Is it possible to have more circular fields, as in the attached? They’re a lot easier to generate in the TP system.
Thanks,
Eli

[jkerns]

Yeah, they don’t have to be square.