Intraoperative preplanning for transperineal ultrasound-guided permanent prostate brachytherapy

Purpose: To describe our approach to intraoperative preplanning (INTRA-OP) for prostate implants and compare it to our standard method using a pre-imp lant volume study (STAND). Methods and Materials: Twenty patients (10 STAND, 10 INTRA-OP) were evaluat ed. Time required for each step of the INTRA-OP procedure was recorded. Ove rall procedure times and operating room times were obtained for all session s. Postimplant dosimetry was CT-based. Results: Mean times required for each stage of the INTRA-OP procedure were as follows: Pre-implant TRUS/prostate stabilization, 26 min; image transfer , 4 min; volume outlining, 8 min; plan generation, 18 min; initial needle l oading, 17 min; seed implantation, 57 min. Mean time for the implantation s ession was 150 min for the INTRA-OP and 120 min for the STAND groups (p = 0 .002). However, this difference is negated if the preplanning volume study is included. In addition, there was a trend toward a shorter time for the I NTRA-OP patients when evaluating mean total operating room times (200 min v s. 220 min; p = 0.07). The mean postimplant %D80 for the INTRA-OP patients was 104.8% vs. 116.2% for the STAND group (p = 0.1). The corresponding %D90 values were 85.3% and 94.6%, respectively (p = 0.08). Conclusion: Intraoperative preplanning increased the time required for the implantation session, but appeared to decrease overall operating room time. The overall convenience of the procedure makes intraoperative preplanning an attractive technique for transperineal ultrasound-guided prostate brachy therapy. (C) 2000 Elsevier Science Inc.