Results of permanent prostate brachytherapy, 13 years of experience at a single institution

Background and purpose: To understand the influence of treatment techniques on the final outcome, as well as the relation of risk groups and of PSA nadir on the outcome, we reviewed our experience over more than 10 years. Patients and methods: Patients were treated in the period 1989 through 2000. Available for this evaluation are 351 patients. The distribution of cases by T stage was T I a, b (9%), Tlc (49%), T2 (42%), and by grading G1 (58%), G2 (38%), G3 (1%) and Gx (3%). The technique of plantation of seeds varied over the years, starting with single seeds using a Mick applicator (104 patients), followed by Rapid strands without (70) and with pre-planning (177). Risk groups are categorised as low (iPSA < 10 ng/ml, Tl-2, grade 1), 116 patients; intermediate (iPSA 10-20 ng/ml, or grade 2-3), 114 patients; and high risk (both factors, or iPSA > 20 ng/ml), 121 patients. The mean follow-up time was 50 months. median 48 and range 24-123 months. Results: Overall actuarial survival at 5 and 7 years was 85 and 76%, respectively. Forty patients died, eight (2%) because of or with prostate cancer. Alive are 310 patients (88%), with 223 patients bNED (71%), 51 (16%) with PSA failure, 21 (7%) with local and 15 (5%) with distant recurrence. Total bNED was 72%. Although results are better since the introduction of Rapid strands, 79% bNED versus 54% bNED for single seeds (P = 0. 14), also the increase in activity per cm(3) prostate volume accounts for this improvement. With pre-planning a significant better result (P < 0.03) is obtained as compared to single seeds or strands without planning. Categorisation into risk groups results in a significant difference (P < 0.007) of bNED with risk factors, respectively, 57% for the high, 75% for the intermediate and 89% for the low risk group. Also PSA nadir had a significant effect on outcome; patients who reach a nadir of less than or equal to 0.5 ng/ml have a 91 % chance of cure. Conclusions: Results of permanent seed implantation improved with the introduction of strands, however, better staging and the increase in activity per cm I prostate volume also contributed to this improvement. A significant better result was obtained with pre-planning. Categorisation in risk groups corresponds very well with treatment outcome. Finally, a strong relation is found with PSA nadir. (C) 2004 Elsevier Ireland Ltd. All rights reserved.