[Retrospective study of 130 patients with organconfined prostate cancer treated with brachytherapy]

The prostate brachytherapy with I 125 seeds has an indication in patients with organconfined prostate cancer. Our objective is to describe the population treated in our institution with permanent I125 seeds implants, the dosimetric characteristics of the technique and the preliminary results of our group-study in terms of evolution and toxicity.

Between May 2000 and March 2003, 130 patients with permanent implants of I125 seeds were treated. Beforehand we did prostate volumetric with transrectum prostate echography in order to assess the configuration of the implant, number of seeds and their place in the prostate with the objective to get a fine coverage of PTV (planet target volume). Stage distribution: 75.72% T1c; 24.28% T2a; Gleason<6, 94%. The PSA pretreatment average was 6.38 ng/ml. The average prostate volume was 30 cc. The 16.67% of the patients included had hormonal treatment previously to get the implants. The average age was 64 years. The characteristic techniques of the implants were: the average width of the needle as 24 (14-35) and the average of the seeds 76 (46-111). Finally the average activity was 0.39 mCi/seed, which means average total implant activity of 80 mCi.

We analyzed 130 patients with average follow up 6 months. A 1 to 2 year surveillance was carried out on 98.9% and the global free disease surveillance (biochemic relapse) of 98.9% at the year and of the 87.8% at the end of the 2 years. The relapse in the low risk patients was 98.8% after the first year and 88.7% at the end of 2 year. On the contrary in the middle risk was of 100% and 83% respectively, although the amount of patients in significantly less. As a relevant acute secondary effects we found slight rectitys or GI (RTOG scale) in 1.4 and that needs synthomatic medication or GII (RTOG scale) in 0.8%. We found slide hematuria or GI (RTOG scale) in the 53% and other measures or GII (RTOG scale) in the 2.64% was needed. Finally we had to set a urinary prove for acute retention in 4.3%.

The prostate brachyterapy is a complex procedure that needs a multidisciplinary team participation in order to be able to carry out. It avoids a long term hospitalization and allows for the patient to have daily activity within a short period of time. Despite the fact of the brief follow-up, the results over biochemical relapse and toxicity were similar to the ones in the literature. Tolerance to the implant was good. It would necessary a longer follow-up in order to be able to come to long term conclusions.