title: Rectal bleeding after hypofractionated radiotherapy for prostate cancer: correlation between clinical and dosimetric parameters and the incidence of grade 2 or worse rectal bleeding.
abstract: OBJECTIVE
  To investigate the incidence and severity of rectal bleeding after high-dose hypofractionated radiotherapy (RT) for prostate cancer, and to explore the factors affecting the incidence of Grade 2 or worse rectal bleeding.
  
  
  METHODS
  The data of 52 patients who had been treated by external beam RT for localized prostate cancer between 1999 and 2002 were analyzed. All the patients had received hypofractionated external beam RT to a total dose of 69 Gy in 3-Gy fractions, three fractions weekly. The clinical and dosimetric factors affecting the incidence of Grade 2 or worse late rectal bleeding were analyzed by univariate and multivariate analyses. The effect of the percentage of the whole rectal volume receiving 30%, 50%, 80%, and 90% of the prescribed radiation dose (V(30), V(50), V(80), and V(90), respectively) on the incidence of rectal bleeding was evaluated.
  
  
  RESULTS
  Of the 52 patients, 13 (25%) developed Grade 2 or worse rectal bleeding. One patient who needed laser coagulation and blood transfusion for the treatment of rectal bleeding was classified as having Grade 3 rectal bleeding. The median time to the development of Grade 2 or worse rectal bleeding was 11 months. The results of the univariate analysis revealed that the presence of a history of diabetes mellitus (p < 0.001), and V(30) >/= 60%, V(50) >/= 40% (p < 0.05), V(80) >/= 25%, and V(90) >/= 15% (p < 0.001) were statistically significant risk factors for the occurrence of Grade 2 or worse rectal bleeding. The results of the multivariate analysis revealed that a history of diabetes mellitus was the most statistically significant risk factor for the occurrence of rectal bleeding after hypofractionated RT for prostate cancer (p < 0.05).
  
  
  CONCLUSIONS
  A history of diabetes mellitus was the most statistically significant risk factor for the occurrence of Grade 2 or worse rectal bleeding after high-dose hypofractionated RT, although dosimetric factors were also closely associated with the risk of rectal bleeding.
authors.affiliation: Department of Radiation Oncology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan. takimoto@showa.gunma-u.ac.jp
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Akimoto
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Muramatsu
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Takahashi
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Saito
authors.forename: Yoshizumi
authors.initials: Y
authors.lastname: Kitamoto
authors.forename: Koichi
authors.initials: K
authors.lastname: Harashima
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Miyazawa
authors.forename: Masami
authors.initials: M
authors.lastname: Yamada
authors.forename: Kazuto
authors.initials: K
authors.lastname: Ito
authors.forename: Kouhei
authors.initials: K
authors.lastname: Kurokawa
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Yamanaka
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakano
authors.forename: Norio
authors.initials: N
authors.lastname: Mitsuhashi
authors.forename: Hideo
authors.initials: H
authors.lastname: Niibe
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D048909:Diabetes Complications; D019583:Dose Fractionation, Radiation; D006471:Gastrointestinal Hemorrhage / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D012002:Rectal Diseases / Q000453:epidemiology / Q000209:etiology*; D012007:Rectum / Q000528:radiation effects*; D012307:Risk Factors