Effectiveness of the I-125 seed permanent implant for localized prostate cancer with the intraoperative planning technique - Comparison with pre-planning technique

Purpose: To report the effectiveness of the I-125 seed permanent implantation for localized prostate cancer with an intraoperative planning method. With one retrospectively compared the two techniques using post-implant CT-based evaluations: a pre-planning method and an intraoperative planning method. Materials and methods: Two hundred forty four patients with T2b or less localized prostate cancer underwent the permanent seed implant between September 2003 and March 2006. One hundred twenty two patients were treated with a pre-planning method while the other half patients were treated with an intraoperative planning. Results: Baseline parameters closely resemble in both groups. However, there were important differences in preoperative prostate volume, source activities, needles and operation time of both groups. Based on a month post-implant CT, patients treated with the pre-planning method marked 155.3 Gy in median prostate D90 (minimal dose covering 90% of the prostate volume) and 92.1% in V100 (percent prostate volume receiving 100% of the prescribed dose). While the intraoperative group marked 169.4 Gy and 97.1%, respectively (p<0.01). Prostate D90 and V100 in the intraoperative group was noted as meaningful improvement. Postoperative dosimetry of the urethra and the rectum followed and conducted as planned. Conclusion: Seed implantation with an intraoperative planning method was more effective than the one with a preoperative planning method. We plan to expand its use of the treatment in the future.