title: Extreme hypofractionation for early prostate cancer: Biology meets technology.
abstract: The aim of this review is to present the available radiobiological, technical and clinical data about extreme hypofractionation in primary prostate cancer radiotherapy. The interest in this technique is based on the favourable radiobiological characteristics of prostate cancer and supported by advantageous logistic aspects deriving from short overall treatment time. The clinical validity of short-term treatment schedule is proven by a body of non-randomised studies, using both isocentric (LINAC-based) or non-isocentric (CyberKnife®-based) stereotactic body irradiation techniques. Twenty clinical studies, each enrolling more than 40 patients for a total of 1874 treated patients, were revised in terms of technological setting, toxicity, outcome and quality of life assessment. The implemented strategies for the tracking of the prostate and the sparing of the rectal wall have been investigated with particular attention. The urinary toxicity after prostate stereotactic body irradiation seems slightly more pronounced as compared to rectal adverse events, and this is more evident for late occurring events, but no worse as respect to conventional fractionation schemes. As far as the rate of severe acute toxicity is concerned, in all the available studies the treatment was globally well tolerated. While awaiting long-term data on efficacy and toxicity, the analysed studies suggest that the outcome profile of this approach, alongside the patient convenience and reduced costs, is promising. Forty-eight ongoing clinical trials are also presented as a preview of the expectation from the near future.
authors.affiliation: Division of Radiation Oncology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
authors.forename: Berardino
authors.initials: B
authors.lastname: De Bari
authors.affiliation: Division of Radiation Oncology, San Camillo-Forlanini Hospitals, Rome, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Arcangeli
authors.affiliation: Division of Radiation Oncology, European Institute of Oncology, Milan, Italy. Electronic address: delia.ciardo@ieo.it.
authors.forename: Delia
authors.initials: D
authors.lastname: Ciardo
authors.affiliation: Division of Radiation Oncology, Sacro Cuore Don Calabria Cancer Care Center, Negrar-Verona, Italy.
authors.forename: Rosario
authors.initials: R
authors.lastname: Mazzola
authors.affiliation: Division of Radiation Oncology, Sacro Cuore Don Calabria Cancer Care Center, Negrar-Verona, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Alongi
authors.affiliation: S.C. di Radioterapia Oncologica, Azienda ospedaliera S. Croce e Carle, Cuneo, Italy.
authors.forename: Elvio G
authors.initials: EG
authors.lastname: Russi
authors.affiliation: Università di Roma, Tor Vergata, U.O.C. di Radioterapia, Policlinico Tor Vergata, Roma, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Santoni
authors.affiliation: Istituto del Radio "O. Alberti", Spedali Civili, Università di Brescia, Brescia, Italy.
authors.forename: Stefano M
authors.initials: SM
authors.lastname: Magrini
authors.affiliation: Division of Radiation Oncology, European Institute of Oncology, Milan, Italy; Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy.
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Jereczek-Fossa
mesh_terms: D018572:Disease-Free Survival; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D000069473:Radiation Dose Hypofractionation; D011832:Radiation Injuries / Q000453:epidemiology*; D016634:Radiosurgery / Q000379:methods*; D012002:Rectal Diseases / Q000453:epidemiology*; D016896:Treatment Outcome; D014570:Urologic Diseases / Q000453:epidemiology*
keywords: Extreme hypofractionation; Outcome evaluation; Primary prostate cancer; Quality of life assessment; Stereotactic body radiation therapy; Toxicity evaluation