Pencil beam scanning is a term used to describe technology available at the newest proton therapy centers, including Cincinnati Children’s. It uses a narrow beam of protons to “paint” a tumor layer by layer. This is similar to what a 3-D printer does when it “prints” a three-dimensional object. In many cases, this allows the protons to better match the exact shape of the tumor.
Older proton therapy technology is referred to as “scattering.” This type of technology is still beneficial, but not as precise.