title: Results and DVH analysis of late rectal bleeding in patients treated with 3D-CRT or IMRT for localized prostate cancer.
abstract: In patients undergoing radiotherapy for localized prostate cancer, dose-volume histograms and clinical variables were examined to search for correlations between radiation treatment planning parameters and late rectal bleeding. We analyzed 129 patients with localized prostate cancer who were managed from 2002 to 2010 at our institution. They were treated with 3D conformal radiation therapy (3D-CRT, 70 Gy/35 fractions, 55 patients) or intensity-modulated radiation therapy (IMRT, 76 Gy/38 fractions, 74 patients). All radiation treatment plans were retrospectively reconstructed, dose-volume histograms of the rectum were generated, and the doses delivered to the rectum were calculated. Time to rectal bleeding ranged from 9-53 months, with a median of 18.7 months. Of the 129 patients, 33 patients had Grade 1 bleeding and were treated with steroid suppositories, while 25 patients with Grade 2 bleeding received argon plasma laser coagulation therapy (APC). Three patients with Grade 3 bleeding required both APC and blood transfusion. The 5-year incidence rate of Grade 2 or 3 rectal bleeding was 21.8% for the 3D-CRT group and 21.6% for the IMRT group. Univariate analysis showed significant differences in the average values from V65 to V10 between Grades 0-1 and Grades 2-3. Multivariate analysis demonstrated that patients with V65 ≥ 17% had a significantly increased risk (P = 0.032) of Grade 2 or 3 rectal bleeding. Of the 28 patients of Grade 2 or 3 rectal bleeding, 17 patients (60.7%) were cured by a single session of APC, while the other 11 patients required two sessions. Thus, none of the patients had any further rectal bleeding after the second APC session.
authors.affiliation: Department of Radiology, Sapporo Medical University School of Medicine, Chuo-ku, Sapporo, Hokkaido, 060-8543, Japan someya@sapmed.ac.jp.
authors.forename: Masanori
authors.initials: M
authors.lastname: Someya
authors.affiliation: Department of Radiology, Sapporo Medical University School of Medicine, Chuo-ku, Sapporo, Hokkaido, 060-8543, Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Hori
authors.affiliation: Department of Radiology, Sapporo Medical University School of Medicine, Chuo-ku, Sapporo, Hokkaido, 060-8543, Japan.
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Tateoka
authors.affiliation: Department of Radiology, Sapporo Medical University School of Medicine, Chuo-ku, Sapporo, Hokkaido, 060-8543, Japan.
authors.forename: Kensei
authors.initials: K
authors.lastname: Nakata
authors.affiliation: Department of Radiology, Hyogo Ion Beam Medical Center, 1-2-1 Koto, Shingu-cho, Tatsuno-shi, Hyogo, 679-5165, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Takagi
authors.affiliation: Department of Radiology, Sapporo Medical University School of Medicine, Chuo-ku, Sapporo, Hokkaido, 060-8543, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Saito
authors.affiliation: Department of Radiology, Sapporo Medical University School of Medicine, Chuo-ku, Sapporo, Hokkaido, 060-8543, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Hirokawa
authors.affiliation: Southern Tohoku Proton Therapy Center, 172-7, Yatsuyamada, Koriyama, Fukushima, 963-8563, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Hareyama
authors.affiliation: Department of Radiology, Sapporo Medical University School of Medicine, Chuo-ku, Sapporo, Hokkaido, 060-8543, Japan.
authors.forename: Koh-Ichi
authors.initials: K
authors.lastname: Sakata
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015984:Causality; D015897:Comorbidity; D019583:Dose Fractionation, Radiation; D004307:Dose-Response Relationship, Radiation; D006471:Gastrointestinal Hemorrhage / Q000453:epidemiology* / Q000517:prevention & control; D006801:Humans; D007564:Japan; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000532:radiotherapy*; D011835:Radiation Protection / Q000379:methods* / Q000706:statistics & numerical data; D020266:Radiotherapy, Conformal / Q000379:methods / Q000706:statistics & numerical data*; D012002:Rectal Diseases / Q000453:epidemiology* / Q000517:prevention & control; D012307:Risk Factors; D016896:Treatment Outcome; D047368:Tumor Burden / Q000528:radiation effects
keywords: 3D-CRT; DVH analysis; IMRT; late rectal toxicity; prostate cancer