PURPOSE: Now that the follow-up time has exceeded 5 years, an estimate of the a/b ratio can be presented. The additional late outcomes in @entity1 treated with three-dimensional conformal external beam radiotherapy for @entity263 using a hypofractionated vs. a standard fractionation regimen are reported from this prospective nonrandomized contemporary comparison. METHODS AND MATERIALS: A total of 114 nonrandomized @entity1 chose hypofractionation delivered in 20 fractions of 3 Gy or 3.15 Gy (mean 3.06 Gy) for @entity263 within a median overall time of 32 days (range, 29-49) using four fractions weekly. A total of 160 comparable @entity1 were contemporarily treated within a median of 55 days (range 49-66). The median follow-up was 66 months (range, 24-95) for the hypofractionated arm and 63 months (range, 36-92) for the standard arm. The percentage of @entity1 in the low-, medium-, and high-risk groups was 36%, 46%, and 18% in the hypofractionated arm and 44%, 50%, and 6% in standard arm (2 Gy), respectively. RESULTS: The 5-year actuarial biochemical absence of disease (prostate-specific antigen nadir  + 2 ng/mL) and disease-free survival rate was the same at 89% in both arms, making the a/b calculation unambiguous. The point ratio of a/b was 1.86 (95% confidence interval, 0.7-5.1 Gy). The 95% confidence interval was determined entirely by the binomial confidence limits in the numbers of @entity1 . Rectal reactions of grade 3 and 4 occurred in 1 of 114 (hypofractionated) and 2 of 160 (standard) @entity1 . CONCLUSIONS: The presented three-dimensional conformal regimen was acceptable, and the a/b value was 1.8, in agreement with other very recent low meta-analyses (reviewed in the "Discussion" section).

Later outcomes and alpha/beta estimate from hypofractionated conformal three-dimensional radiotherapy versus standard fractionation for XXXX .

@entity1 :: ('9606', 'Species') :: ['patients'] @entity263 :: ('MESH:D011471', 'Disease') :: ['localized prostate cancer']
@entity263 :: (MESH:D011471,Disease) :: ['localized prostate cancer']
