Beitragstitel | Long-term oncological and functional follow-up in low dose rate brachytherapy (LDR-BT) for prostate cancer: results from the prospective nation-wide Swiss LDR Prostate Brachytherapy Registry |
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Beitragscode | M027 |
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Präsentationsform | Freie Mitteilungen |
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Abstract-Text |
Background and Objective LDR-BT is an effective therapy for organ-confined prostate cancer with comparable results to radical prostatectomy and external beam radiation therapy but results originate manly from single-center cohorts and retrospective analyses. The Swiss Prostate LDR-Brachytherapy Registry (SPB) is a nationwide cohort with 12 centers all over Switzerland that operates a prospective data collection of LDR-BT patients since 09/2004 initially based on a regulatory requirement forwarded by the Swiss federal office of public health. The primary objective of the registry is to substantiate the oncologi-cal (biochemical recurrence free survival = BRFS) outcomes of LDR-BT in relation to risk factors and radiation dose with a prospective multicentric cohort. Material and Methods Data was collected at baseline, 6 weeks, 3, 6 and 12 months post-implantation and annually thereafter. Prostate cancer was categorized as low-, intermediate-, or high risk accord-ing to the D’Amico Classification. Functional outcomes were assessed. LDR-BT was performed with 125-Iodine seeds. Dosimetry was performed 6 weeks after implantation based on the European Society for Radiotherapy and Oncology recommen-dations. Kaplan-Meier curves were used for BRFS with first PSA above the nadir + 2 as the date of relapse for biochemical failure (RTOG-ASTRO Phoenix Definition) and the last follow-up date. Results Of 1580 patients in the database, 1291 (81.7 %) were evaluable for therapy outcome. Me-dian follow up was 37.1 months (range 3.0 – 141.6). Higher BRFS was found for Gleason score ≤ 3+4 (p = 0.03, log rank test) and initial PSA level of < 10ng/ml (p < 0.001). D'Amico Risk groups were significant for recurrence (p < 0.001), with a hazard ratio 2.38 for a group of intermediate and high risk patients vs low risk. D90 after 6 weeks differed signifi-cantly in the group without (168.2 Gy) and the group with relapse (158.8 Gy). Functional outcomes and questionnaires showed a deterioration 6 weeks after BT with return to base-line after 3 years. Major limitation is a relevant loss in follow-up. Conclusion Our results are in line with other studies showing LDR-brachytherapy is associated with a low rate of therapy related toxicity and can be used as first line treatment. In order to provide a better therapy recommendation, prospective randomized controlled, multicenter studies with direct comparison of the different therapy options for localized prostate cancer would be necessary. |