title: Higher-than-conventional radiation doses in localized prostate cancer treatment: a meta-analysis of randomized, controlled trials.
abstract: OBJECTIVE
  To determine in a meta-analysis whether the outcomes in men with localized prostate cancer treated with high-dose radiotherapy (HDRT) are better than those in men treated with conventional-dose radiotherapy (CDRT), by quantifying the effect of the total dose of radiotherapy on biochemical control (BC).
  
  
  METHODS
  The MEDLINE, EMBASE, CANCERLIT, and Cochrane Library databases, as well as the proceedings of annual meetings, were systematically searched to identify randomized, controlled studies comparing HDRT with CDRT for localized prostate cancer. To evaluate the dose-response relationship, we conducted a meta-regression analysis of BC ratios by means of weighted linear regression.
  
  
  RESULTS
  Seven RCTs with a total patient population of 2812 were identified that met the study criteria. Pooled results from these RCTs showed a significant reduction in the incidence of biochemical failure in those patients with prostate cancer treated with HDRT (p < 0.0001). However, there was no difference in the mortality rate (p = 0.38) and specific prostate cancer mortality rates (p = 0.45) between the groups receiving HDRT and CDRT. However, there were more cases of late Grade >2 gastrointestinal toxicity after HDRT than after CDRT. In the subgroup analysis, patients classified as being at low (p = 0.007), intermediate (p < 0.0001), and high risk (p < 0.0001) of biochemical failure all showed a benefit from HDRT. The meta-regression analysis also detected a linear correlation between the total dose of radiotherapy and biochemical failure (BC = -67.3 + [1.8 x radiotherapy total dose in Gy]; p = 0.04).
  
  
  CONCLUSIONS
  Our meta-analysis showed that HDRT is superior to CDRT in preventing biochemical failure in low-, intermediate-, and high-risk prostate cancer patients, suggesting that this should be offered as a treatment for all patients, regardless of their risk status.
authors.affiliation: Department of Radiation Oncology, Marilia School of Medicine, São Paulo, Brazil. gusviani@gmail.com
authors.forename: Gustavo Arruda
authors.initials: GA
authors.lastname: Viani
authors.forename: Eduardo Jose
authors.initials: EJ
authors.lastname: Stefano
authors.forename: Sergio Luis
authors.initials: SL
authors.lastname: Afonso
mesh_terms: D004307:Dose-Response Relationship, Radiation; D006801:Humans; D008297:Male; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000401:mortality / Q000532:radiotherapy*; D016032:Randomized Controlled Trials as Topic; D012044:Regression Analysis; D015996:Survival Rate
chemical_list: D017430:Prostate-Specific Antigen