Permanent prostate brachytherapy preplanned technique: The modern Seattle method step-by-step and dosimetric outcomes

Abstract

PurposeTo describe, step-by-step, the current Seattle preplan technique, and report the dosimetric outcomes on 1,131 consecutively such treated prostate brachytherapy patients. Methods and MaterialsOne thousand one hundred thirty one patients with prostate cancer were treated with iodine-125 (125I), palladium-103 (103Pd), or cesium-131 (131Cs) using a preplanned template-guided transrectal ultrasound-guided approach between January 2005 and August 2007. Day one computed tomography (CT) scans were taken for postimplantation dose-volume histogram evaluations. Postoperative prostate contours were drawn by one author (DN) on CT images taken on postoperative day one. ResultsThe volume of prostate receiving 100% of prescription dose (V100) and percent dose to 90% of the prostate (%D90) were 95% and 106% for 558 monotherapy 125I implants, 91% and 102% for 327 103Pd implants, and 97% and 111.5% for 13 131Cs implants, respectively. The median V100 and percent D90 were 91% and 101% for five boost 125I implants, 92% and 104% for 228 boost 103Pd implants. The median rectal volume receiving 100% of prescription dose (RV100) for 125I, 103Pd, and 131Cs monotherapy implants were 0.3, 0.13, and 0.38cc, and for 125I and 103Pd boost implants were 0.16 and 0.13cc, respectively. No patient received an RV100 of >0.92cc. ConclusionsModern preplanned template and ultrasound-guided prostate brachytherapy can consistently result in excellent prostate dosimetry and rectal sparing.