Biological effective dose for comparison and combination of external beam and low-dose rate interstitial brachytherapy prostate cancer treatment plans

摘要: Abstract We report a methodology for comparing and combining dose information from external beam radiotherapy (EBRT) interstitial brachytherapy (IB) components of prostate cancer treatment using the biological effective (BED). On prototype early-stage patient treated with EBRT low-dose rate I-125 brachytherapy, 3-dimensional distribution was calculated each IB portions treatment. For component treatment, BED on point-by-point basis to produce distribution. These individual distributions could then be summed combined therapies. dose-volume histograms (DVHs) prostate, urethra, rectum, bladder were produced compared various combinations IB. Transformation enabled computation relative contribution modality dose, as weighting varied. The BED-DVHs urethra demonstrated dramatically increased inhomogeneity introduction even small However, increasing portion resulted in lower surrounding normal structures, evidenced by rectum. Conformal conventional successfully transformed common “language” comparison merging radiation plans. results this analysis can assist physicians quantitatively determining best combination modalities patients.