title: High-dose-rate intensity modulated brachytherapy with external-beam radiotherapy improves local and biochemical control in patients with high-risk prostate cancer.
abstract: Purpose Our aim was to report the 8-year outcome of local dose escalation using high-dose-rate conformal brachytherapy combined with external irradiation for patients with high-risk prostate cancer. Material and methods From June 1998 to June 2007, 134 patients with high-risk localized prostate cancer were prospectively enrolled in the study. The median follow-up was 45 months (12-107). Only patients considered as having high-risk criteria were accepted [prostate-specific antigen (PSA) > or =20 ng/ml and/or Gleason >7 and/or stage > or =T3a or two intermediate-risk criteria: PSA 11-19 ng/ml, Gleason 7, stage T2b-c]. The total dose applied by external beam radiotherapy was 46 Gy in 200-cGy daily fractions. High-dose-rate brachytherapy was performed at the end of weeks 1 and 3 of the 5-week radiotherapy course. The doses administered in each application was 1,150 cGy. Any patient free of clinical or biochemical evidence of disease was termed b-NED. Actuarial rates of outcome were calculated by Kaplan. Meier analysis and compared using the log-rank test. Cox regression models were used to establish prognostic factors of the measures of outcome. Results Mean follow-up for the entire group was 45 months (range 12-107). The overall survival (OS) according to Kaplan-Meier estimates was 85% (+/-5) at 5 and 8 years. The 5 and 8 years for biochemical control were 80% (+/-4%) and 73% (+/-7%), respectively, whereas for failure in tumor-free survival (TFS), they were 82% (+/-3) at 5 and 8 years, respectively. The 8-year cause-specific mortality was 10% (+/-4%). The multivariate Cox regression analyses identified the number of poor prognostic factors as independent for biochemical failure. Our report includes only patients considered as high risk, and the 8-year b-NED survival rate was 83% for patients with two intermediate-risk criteria, 78% for patients with one poor prognostic factor, 56% for two and 35% for all three (p = 0.001). There were no urethral strictures and/or urinary incontinence. Gastrointestinal toxicity grade 2 was 7.5%. Conclusions The 8-year results confirm the feasibility and effectiveness of external-beam radiation therapy with conformal high-dose-rate brachytherapy boost for patients with high-risk tumor. The late toxicity rates were low, corroborating the excellent dose conformity.
authors.affiliation: Department of Radiation Oncology, Hospital Central de Asturias, Oviedo, Asturias, Spain. pprada@telecable.es
authors.forename: P J
authors.initials: PJ
authors.lastname: Prada
authors.forename: H
authors.initials: H
authors.lastname: González
authors.forename: J
authors.initials: J
authors.lastname: Fernández
authors.forename: P
authors.initials: P
authors.lastname: Bilbao
mesh_terms: D001918:Brachytherapy / Q000379:methods*; D018572:Disease-Free Survival; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D017430:Prostate-Specific Antigen / Q000097:blood / Q000528:radiation effects*; D011471:Prostatic Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D011878:Radiotherapy / Q000379:methods; D012307:Risk Factors
chemical_list: D017430:Prostate-Specific Antigen