EP-1493 ALTERNATIVE REGIMENS FOR PROSTATE CANCER TREATMENT USING RADIATION THERAPY

Abstract

Purpose/Objective: The purpose of this work was to determine biologically equivalent alternative regimens for the treatment of prostate cancer using External Beam Radiotherapy (EBRT) and Low Dose-Rate Brachytherapy (LDRBT) with 125I implants and to evaluate the sensitivity of these regimens to different sets of radiobiological parameters of the LinearQuadratic (LQ) model. Materials and Methods: The biological effective dose (BED) was used to determinate equivalences of the two modalities assuming that BED values are additive for different treatment techniques. Two sets of parameters were employed considering whether accelerated repopulation of the clonogens during the treatment time occurs: LQ1) α/β=3.1 Gy, α=0.15 Gy-1,μ=2.6 h-1, Tpot=42 days, N=3x106 clonogens, or not, LQ2) α/β=1.5 Gy, α=0.03 Gy