Evaluation of radiobiologic biochemical control in a large permanent prostate brachytherapy population from a single institution using AAPM TG-137 parameters

摘要: Abstract Purpose To re-evaluate prostate implant dosimetry using American Association of Physicists in Medicine Task Group 43 parameters and the radiobiologic approach 137. Methods Materials Among 1473 consecutive patients implanted with iodine-125 or palladium-103 sources before March 2006, there have been 55 biochemical failures. The dosimetric quality parameter, D 90 , was updated according to radionuclide era implant. For each patient, biologically equivalent dose (BED) tumor control probability (TCP) were calculated from plus any external beam recommended indices equations. Results There no significant difference BED between failures nonfailures, 148 ± 27 Gy 145 ± 24 Gy, respectively ( p  = 0.352). TCP 0.90 ± 0.26 for 0.93 ± 0.21 nonfailures  = 0.414). Cox regression analysis found that neither nor predicted either entire population within radionuclide-dependent era. only overall predictors era, Gleason score, percent positive biopsies. Improvements over first 300 evident, but remained a better predictor outcome than sequence number. Conclusion In large population, derived did not predict failure. Apparently, too few had total BEDs below level necessary optimum control. A learning curve extended hundreds plateauing changes seed characterization also pronounced effect.