title: Acute and late complications after hypofractionated intensity modulated radiotherapy in prostate cancer.
abstract: OBJECTIVE
  The present study compared the complications associated with hypofractionated intensity-modulated radiation therapy (Hypo-IMRT) of prostate cancer to conventionally fractionated IMRT (Conv-IMRT).
  
  
  METHODS
  Hypo-IMRT delivered 70 Gy in 28 fractions, whereas Conv-IMRT delivered 78 Gy in 39 fractions. Toxicity was graded with the Common Terminology Criteria for Adverse Events, version 4.0, weekly during radiotherapy, 1 month after radiotherapy, and annually in both patient groups.
  
  
  RESULTS
  The median follow-ups were 39.1 and 38.7 months for patients in the Hypo- and Conv-IMRT groups, respectively. There was no significant difference in rates of acute and late adverse events. The proportions of grade 2 acute genitourinary complications were 48.4 and 51.2% in the Hypo- and Conv-IMRT groups, respectively. The presence of a baseline International Prostate Symptom Score (IPSS) of ten or more was the only significant prognostic factor for grade 2 acute genitourinary toxicity. The incidence of grade 2 late rectal hemorrhage at 3 years was 3.2 and 3.5% in the Hypo- and Conv-IMRT groups, respectively. Small rectal volume was significantly associated with grade 2 late rectal hemorrhage.
  
  
  CONCLUSIONS
  Regarding acute and late adverse events, hypofractionated IMRT for prostate cancer was well tolerated and comparable with conventionally fractionated IMRT. Clinical trial registration no. UMIN000003218.
authors.affiliation: Department of Radiation Oncology, Cancer Institute Hospital of the Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan. takuyo.kozuka@jfcr.or.jp.
authors.forename: Takuyo
authors.identifier: http://orcid.org/0000-0002-4527-2638
authors.initials: T
authors.lastname: Kozuka
authors.affiliation: Department of Physics, Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nakano
authors.affiliation: Department of Physics, Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Hashimoto
authors.affiliation: Department of Radiation Oncology, Japanese Red Cross Society Suwa Hospital, Nagano, Japan.
authors.forename: Kotaro
authors.initials: K
authors.lastname: Gomi
authors.affiliation: Department of Radiation Oncology, Cancer Institute Hospital of the Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
authors.forename: Keiko Nemoto
authors.initials: KN
authors.lastname: Murofushi
authors.affiliation: Department of Radiation Oncology, Cancer Institute Hospital of the Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
authors.forename: Minako
authors.initials: M
authors.lastname: Sumi
authors.affiliation: Department of Urology, Cancer Institute Hospital of the Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Yonese
authors.affiliation: Department of Radiation Oncology, Cancer Institute Hospital of the Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Oguchi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019583:Dose Fractionation, Radiation; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000209:etiology*; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods
keywords: Acute toxicity; Hypofractionation; Intensity modulated radiotherapy; Late toxicity; Prostate cancer