A proton therapy treatment gantry, such as this one at Roberts Proton Therapy Center, delivers precise proton beams to difficult-to-reach tumors. Photo credit: Penn Medicine's Roberts Proton Therapy Center and…

After losing his mother to breast cancer and then fighting testicular cancer himself, Olympic gold medalist Scott Hamilton started a foundation to help those touched by the disease. LAURA PANJWANI…

By DENISE ROLAND for The Wall Street Journal Proton-beam therapy machines, such as this one in the Czech Republic, are used in treating cancer patients. PHOTO: PETR DAVID JOSEK/ASSOCIATED PRESS…