Proton radiation in the management of localized cancer.

Proton radiation therapy has been available for decades. However, until recently it was only applied to a small number of patients at approximately 20 centers worldwide. Increased clinical experience with protons, as well as extensive research in the physics, biology and clinical aspects of proton therapy, have recently led to a huge interest in proton therapy among radiation oncologists. In addition, the cost for facilities is expected to decrease. Many proton therapy facilities are currently being built and planned worldwide. It is expected that the number of patients treated with protons will increase substantially in the near future. This article summarizes the rationale for (proton) radiation therapy and addresses the promises and challenges of proton-beam therapy in the management of localized cancer.