The University of Maryland School of Medicine and its development partner, Maryland Proton Treatment Holdings (MPTH), recently opened the Maryland Proton Treatment Center at the BioPark on the campus of the University of Maryland, Baltimore. The center is one of only about 20 proton treatment centers in the United States, and the only one in the Baltimore-Washington region. Proton beam radiation therapy uses streams of protons (tiny particles with a positive charge) to kill tumor cells. Proton beam radiation is different from X-ray radiation, and can reduce the amount of radiation damage to healthy tissue near a tumor. It is used to treat cancers of the head and neck and organs such as the brain, eye, lung, spine, and prostate. Proton therapy is also an important treatment option for pediatric patients.