Proton-beam therapy for tumors of the CNS.

The focus of this review is proton radiotherapy for primary neoplasms of the brain. Although glial cells are among the most radioresistant in the body, the presence of sensitive critical structures and the high doses needed to control CNS tumors present a formidable challenge to the treating radiation oncologist. Treatment with conventional photon radiation at doses required to control disease progression all too often results in unacceptable toxicity. Protons have intrinsic properties that often allow radiation oncologists to deliver a higher dose to the tumor compared with photons, while at the same time offering better sparing of normal tissues. Recognition of these advantages has resulted in development of many new proton treatment facilities worldwide.