Prostate Specific Antigen Based Disease Control Following Ultrasound Guided sup 125 Iodine Implantation for Stage T1/T2 Prostatic Carcinoma

Abstract

Purpose We report the prostate specific antigen (PSA) based recurrence-free survival rate after 125iodine (sup 125 I) implantation for early stage prostatic carcinoma. Materials and Methods A total of 197 patients with clinical stage T1 or T2 prostatic carcinoma underwent outpatient 125I seed implantation. Followup was 1 to 7 years (median 3). Pretreatment serum PSA levels were elevated (greater than 4.0 ng./ml.) in 138 patients (70 percent). There were 105 well differentiated (Gleason score 2 to 4), 87 moderately differentiated (Gleason score 5 to 6) and 5 indeterminate tumors. The prescribed minimum prostatic dose was 160 Gy. The total dosage of 125I implanted ranged from 15 to 62 mCi. (median 37). Staging lymph node dissection and seminal vesicle biopsies were not routinely performed. Results Among 138 patients with an elevated PSA level before implantation and no prior hormonal treatment, the PSA value returned to normal in 98 percent and decreased to less than 1.0 ng./ml. in 82 percent within 24 months of treatment. In 97 percent of those 138 patients the PSA level decreased to less than 1.0 ng./ml. at 48 months after implantation. Of 8 patients with an increasing PSA value 5 also had clinically evident failure. The actuarial rate of chemical (increasing PSA) or clinical failure at 5 years following implantation was 7 percent, with 15 patients still at risk at 5 years. There was a trend for higher failure rates among patients with higher pretreatment PSA levels (p = 0.57), Gleason scores 5 and 6 versus 2 to 4 (p = 0.51) or higher stage of disease (p = 0.17). Conclusions There is a high rate of clinical and chemical freedom from progression following 125I implantation for select patients with early stage prostatic carcinoma.