Intensity module radiation therapy (IMRT) can be delivered multiple ways to treat a brain tumor. For example, 7-field IMRT has the beam come from seven different angles. Each beam can be weighted differently. There is also arc therapy, which uses partial or complete arcs to deliver the radiation to the tumor. Tomotherapy delivers the dose in 360 degrees around the target.
To pick the best plan, doctors observe how well the dose they want hugs the tumor, and how little of a scatter dose there is in areas outside the tumor.
To pick the best plan, doctors observe how well the dose they want hugs the tumor, and how little of a scatter dose there is in areas outside the tumor.