title: Particle radiotherapy for prostate cancer.
abstract: Recent advances in external beam radiotherapy have allowed us to deliver higher doses to the tumors while decreasing doses to the surrounding tissues. Dose escalation using high-precision radiotherapy has improved the treatment outcomes of prostate cancer. Intensity-modulated radiation therapy has been widely used throughout the world as the most advanced form of photon radiotherapy. In contrast, particle radiotherapy has also been under development, and has been used as an effective and non-invasive radiation modality for prostate and other cancers. Among the particles used in such treatments, protons and carbon ions have the physical advantage that the dose can be focused on the tumor with only minimal exposure of the surrounding normal tissues. Furthermore, carbon ions also have radiobiological advantages that include higher killing effects on intrinsic radio-resistant tumors, hypoxic tumor cells and tumor cells in the G0 or S phase. However, the degree of clinical benefit derived from these theoretical advantages in the treatment of prostate cancer has not been adequately determined. The present article reviews the available literature on the use of particle radiotherapy for prostate cancer as well as the literature on the physical and radiobiological properties of this treatment, and discusses the role and the relative merits of particle radiotherapy compared with current photon-based radiotherapy, with a focus on proton beam therapy and carbon ion radiotherapy.
authors.affiliation: Ion Beam Therapy Center, SAGA-HIMAT Foundation, Tosu, Sagan, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Shioyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsuji
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Suefuji
authors.forename: Makoto
authors.initials: M
authors.lastname: Sinoto
authors.forename: Akira
authors.initials: A
authors.lastname: Matsunobu
authors.forename: Shingo
authors.initials: S
authors.lastname: Toyama
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Nakamura
authors.forename: Sho
authors.initials: S
authors.lastname: Kudo
mesh_terms: D018572:Disease-Free Survival; D006801:Humans; D008297:Male; D011467:Prostate / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods*; D016896:Treatment Outcome
keywords: carbon ion radiotherapy; intensity-modulated radiation therapy; prostate cancer; proton beam therapy