125I reimplantation in patients with poor initial dosimetry after prostate brachytherapy

Abstract

Purpose In this case report, we describe 7 patients with suboptimal dosimetry after 125I prostate brachytherapy who underwent a second implant procedure to improve the dosimetric coverage of the prostate. Methods and materials Seven patients underwent second 125I implants for suboptimal dosimetry after their initial implant for prostate cancer. The pretreatment characteristics (clinical stage, Gleason score, initial prostate-specific antigen level, location of positive cores, International Prostate Symptom Score, potency, use of androgen suppression, initial implant planning characteristics) were noted. The “Day 30” CT-based dosimetry parameters after the first implant and “Day 0” CT-based dosimetry after the reimplant were recorded (volumes of prostate and rectum covered by 100% and 150% of the dose and dose covering 90% of the prostate volume). The toxicity of the second procedure, International Prostate Symptom Scores before and after reimplantation, the clinical course, and prostate-specific antigen outcomes after reimplant were examined. We described our reimplant planning and intraoperative procedure. Results In all 7 patients, we were able to achieve very favorable dosimetry after the second procedure. The acute toxicity of the reimplant procedure was reasonably low, and the short-term prostate-specific antigen outcome has been favorable. Conclusion It is possible to add more seeds safely to the dosimetrically cool area after the initial brachytherapy procedure and achieve excellent postimplant dosimetry with acceptable acute toxicity. The ultimate benefits and long-term toxicity of reimplantation are unknown.