Estudio retrospectivo de pacientes tratados con braquiterapia prostática con I-125 en el Instituto Catalán de Oncología

Introduction. Prostate brachytherapy is indicated in patients with initial-stage prostate cancer. Our objective is to describe, in a series of patients treated in our institution with permanent implants of¹²⁵I seeds, the dosimetric characteristics of the technique and the preliminary results together with the toxicity profile, biological relapse and survival. Material and methods. Between May 2000 and September 2003, we treated 153 patients using permanent transperineal¹²⁵I seed implants (target dose of 145 Gy), of whom 130 were included in the analysis for having a minimum of 6 months follow-up. Distribution by stage was: 73.85% (n=96) Tlc and 26.15% (n=34) T2a. Gleason <6,97% (n=127); median prostate specific antigen (PSA) pre-treatment was 6.24 ng/ml. The median prostate volume was 28 cc; 34 patients had received previous hormonal therapy prior to the implants. Median age was 65 years. Results. There were 130 patients with >6 months follow-up in the analysis (median age = 65 years) of whom 18.46% (n=24) had attended the Radiotherapy Service for the first time and who had previously been prescribed hormonal therapy. Technical characteristics of the implants: median number of needles = 24 (range 14–35); median number of seeds = 76 (range 46–111); median activity = 14.46 MBq/seed; total activity implanted (median) = 1,121.1 MBq. The median follow-up was 20 months (6–42 months). Survival free of disease at 1 and 2 years was 99.1 % and 89.9%, respectively. Based on the stratification of risk groups, 99% and 92.1% of the patients of low risk continued free of the disease at 1 and 2 years, respectively while for those patients of intermediate risk these values were 100% and 77.8% respectively. Frequency of relevant secondary effects were rectitis G1 5.38% and G2 of 1.54%; haematuria G2 44.62% and G3 1.54%. A probe was necessary to resolve acute urine retention in 3.85%. Conclusions. Prostate brachytherapy is a complex procedure that requires the participation of a multi-disciplinary team, it precludes prolonged hospitalisation and allows the patient to resume normal activity within a short period. Although the mean follow-up time is short, the results with respect to survival free of biochemical relapse and toxicity are comparable to those described in the literature. The patient tolerance of the implant has been good. Longer follow-up is necessary to confirm the long-term conclusions.