10-year biochemical (prostate-specific antigen) control of prostate cancerwith I-125 brachytherapy

Purpose: To report 10-year biochemical (prostate-specific antigen [PSA]) ou tcomes for patients treated with I-125 brachytherapy as monotherapy for ear ly-stage prostate cancer. Methods and Materials: One hundred and twenty-five consecutively treated pa tients, with clinical Stage T1-T2b prostate cancer were treated with 125I b rachytherapy as monotherapy, and followed with PSA determinations. Kaplan-M eier estimates of PSA progression-free survival (PFS), on the basis of a tw o consecutive elevations of PSA, were calculated. Aggregate PSA response by time interval was assessed. Comparisons were made to an earlier-treated co hort. Results: The overall PSA PFS rate achieved at 10 years was 87% for low-risk patients (PSA < 10, Gleason Sum 2-6, T1-T2b). Of 59 patients (47%) followe d beyond 7 years, 51 (86%) had serum PSAs less than 0.5 ng/mL; 48 (81%) had serum PSAs less than 0.2 ng/mL. Failures were local , 3.0%; distant, 3.0%. No patients have died of prostate carcinoma. The proportion of patients wi th a PSA <less than or equal to> 0.2 ng/mL continued to increase until at l east 7-8 years posttherapy. A plot of PSA PFS against the proportion of pat ients achieving serum PSA of less than 0.2 ng/mL suggests a convergence of these two endpoints at 10 years. Patients treated in the era of this study (1988-1990) experienced a statistically improved PFS compared with an earli er era (1986-1987). This difference appears independent of patient selectio n, suggesting that the maturation of the technique resulted in improved bio chemical control. Conclusion: With modern technique, monotherapy with 125I achieves a high ra te (87%) of biochemical and clinical control in patients with low-risk dise ase at 10 years. The decline of PSA following brachytherapy with low-dose-r ate isotopes can be protracted. Absolute PSA and PFS curves merge, and are comparable at 10 years. (C) 2001 Elsevier Science Inc.