Comparison of Two Commercial Treatment Planning Systems Variseed and Mim for Low-Dose-Rate Prostate Brachytherapy

Abstract

operative transrectal ultrasound volume (CT/TRUS ratio) was significantly less for thin seed patients than for standard seed patients (p50.0015). For the standard seed group, the volumetric difference between the preoperative TRUS and post-operative CT tended to be greater in smaller sized prostates. However, in the thin seed patients, the volume variation between the preoperative TRUS and postoperative CT was independent of prostate size. Of the factors considered a priori to be potential predictors of prostate swelling (initial prostate volume, number of needles, prior hormonal therapy, group, operative time), only group was shown to significantly impact on prostate swelling on multivariate analysis, with less swelling in thin seed patients. Conclusions: I thin seeds (ThinSeed, Oncura Pty Ltd) are associated with an initial learning curve in terms of operative time, even among experienced brachytherapists. Their ability to reduce prostate swelling, and the implications in terms of reducing timing-dependent variations in post-implant dosimetry, as well as acute urinary morbidity, deserves further exploration.