Fortunately cancer is rare in children, however solid tumors (not leukemia) can often grow rapidly and to a large size before they are detected. If possible, surgical removal is recommended unless the danger or disability to the child prohibits this. Many childhood cancers also respond to chemotherapy, but a number of tumors will also require radiation therapy. Radiation delivery is especially challenging in children because the bones and hormone producing glands are still growing and are sensitive to the effects of radiation. Since Tomotherapy can precisely target such tumors, while relatively sparing adjacent structures, it is possible to limit the dosage to growing bones and glands while treating inoperable cancers to effective doses. It is even possible to treat the entire brain and spinal cord to effective doses, while protecting the bones of the spine and head enough to permit relatively normal growth. Some institutions are even treating the entire bone marrow instead of the entire body in preparation for bone marrow transplantation.

With conventional radiation, even with IMRT, children must sometimes be positioned lying on their stomach or even standing (for total body treatment). Since the Tomotherapy beam rotates around the child like a CT scanner, all children can be treated comfortably lying on their back.