Proton therapy is a type of radiation therapy that uses protons rather than x-rays. It painlessly delivers radiation to treat some types of cancer. Proton therapy is a promising new type of cancer treatment, but its possible benefit over traditional radiation therapy is still being studied. Research is ongoing in clinical trials to see how it compares.

In general, proton therapy has fewer side effects than other types of radiation therapy. This is because it can be targeted more directly at the tumor and does less damage to other tissue.