Because protons can target a tumor with about 60 percent less radiation to surrounding structures, doctors can select an appropriate dose without fear of damaging healthy tissue and causing severe side effects. The treatment is most beneficial in children, but is also effective in adults who have small, well-defined tumors. It is especially useful for treating tumors adjacent to sensitive tissues that must be protected from radiation exposure. Although the machines necessary to generate proton beams are enormous and expensive, several companies are developing smaller, less-expensive models that may soon make the therapy available to more patients nationwide. Research is under way to determine whether proton therapy can be more effective when combined with other treatments.
Sources: National Cancer Institute, American Society of Clinical Oncology