10-YEAR DISEASE-FREE SURVIVAL AFTER TRANSPERINEAL SONOGRAPHY-GUIDED I-125 BRACHYTHERAPY WITH OR WITHOUT 45-GRAY EXTERNAL-BEAM IRRADIATION IN THE TREATMENT OF PATIENTS WITH CLINICALLY LOCALIZED, LOW TO HIGH GLEASON GRADE PROSTATE CARCINOMA

BACKGROUND. The authors report observed 10-year brachytherapy results in the treatment of 152 consecutive patients with clinically organ-con fined prostate carcinoma. METHODS. One hundred and fifty-two consecuti ve patients with T1-T3, low to high Gleason grade, prostate carcinoma were treated between January 1987 and June 1988 at Northwest Hospital in Seattle, Washington. Their median age was 70 years (range, 53-92 ye ars). Of these 152 patients, 98 (64%) received an iodine-125 implant a lone (Group 1), and the remaining 54 patients (36%), who were judged t o have a higher risk of extraprostatic extension, also were treated wi th 45 gray (Gy) of external beam irradiation to the pelvis (Group 2). No patient underwent lymph node sampling, and none received androgen a blation therapy. Multivariate regression and the Mann-Whitney rank sum test were used for statistical analysis. Preoperative patient data wi th associated success or failure outcomes at 10 years after treatment were used for training and validating a back-propagation neural networ k prediction program. RESULTS. The average preoperative prostate speci fic antigen (PSA) value, clinical stage, and Gleason grade were 11.0 n g/mL, T2, and 5, respectively. The median posttreatment follow-up was 119 months (range, 3-134 months). Overall survival 10 years after trea tment was 65%. At last follow-up only 3 of the 152 patients (2%) had d ied of prostate carcinoma. Ninety-seven patients (64%) remained clinic ally and biochemically free of disease at 10 years of follow-up and ha d an average PSA value of 0.18 ng/mL (range, 0.01-0.5 ng/mL). In these patients a period of 42 months was required to reach the average PSA (0.5 ng/mL). The median to last PSA follow-up was 95 months (range, 3- 134 months). Postoperative needle biopsies were negative in 56% of pat ients, positive in 15% of patients, and not available in 29% of patien ts. Only 6% of patients developed bone metastasis. At 10 years there w as no statistically significant difference in treatment outcome betwee n patients who received iodine-125 alone, and those who received iodin e-125 with 45-Gy external beam irradiation (P = 0.08). Nevertheless, i n these two groups preoperative PSA, stage, and Gleason grade were sig nificantly different (P < 0.01). In the artificial neural network anal ysis, pretreatment serum PSA was the most accurate predictor of diseas e-free survival. CONCLUSIONS. Percutaneous prostate brachytherapy is a valid and efficient option for treating patients with clinically orga n-confined, low to high Gleason grade, prostate carcinoma. Observed 10 -year follow-up documents serum PSA levels superior to those reported in several published external beam irradiation series, and comparable to those published in a number of published radical prostatectomy seri es. (C) 1998 American Cancer Society.