• Michael J Zelefsky, Yoshiya Yamada, Gil'ad N Cohen, Alison Shippy, Heather Chan, David Fridman, and Marco Zaider.
• Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA. zelefskm@mskcc.org
• Int. J. Radiat. Oncol. Biol. Phys. 2007 Jan 1; 67 (1): 65-70.

PurposeTo report the 5-year tumor control and toxicity outcomes for patients with localized prostate treated with I-125 permanent implantation using an intraoperative real-time conformal planning technique.Methods And MaterialsBetween January 1998 and June 2002, 367 patients with prostate cancer were treated with I-125 permanent interstitial implantation using a transrectal ultrasound-guided approach. Real-time intraoperative treatment planning which incorporated inverse planning optimization was used. The median follow-up time was 63 months.ResultsThe median V100 and D90 were 96% and 173 Gy, respectively. In 96% of cases a D90 of >140 Gy was achieved. The median urethral and rectal doses were 100% and 33% of the prescription doses, respectively. The 5-year PSA relapse-free survival outcomes for favorable and intermediate risk patients according to the ASTRO definition were 96% and 89%, respectively. In these patients no dosimetric parameter was identified which influenced the biochemical outcome. Of 38% who developed acute Grade 2 urinary symptoms, 63% had resolution of their symptoms within a median time of 6 months. The incidence of late rectal and urinary Grade 3 or higher toxicities were 1% and 4%, respectively. Seven percent (n = 27) developed late rectal bleeding (Grade 2) and 19% experienced late Grade 2 urinary symptoms.ConclusionReal-time intraoperative planning consistently achieved optimal coverage of the prostate with the prescription dose with concomitant low doses delivered to the urethra and rectum. Biochemical control outcomes were excellent at 5 years and late toxicity was unusual. These data demonstrate that real-time planning methods can consistently and reliably deliver the intended dose distribution to achieve an optimal therapeutic ratio between the target and normal tissue structures.

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