Permanent interstitial brachytherapy (seeds) for patients with primary localized prostate cancer: analysis of 100 patients

The aim of this retrospective study was to evaluate late toxicity and biochemical disease-free survival of patients with primary localised prostate cancer, who had been treated with permanent seed implantation at the radiotherapy department of the Medical University of Vienna. Between 08/1999 and 11/2006 100 patients were treated with ultrasound guided transperineal seed implantation (94 patients with Iodine and 6 patients with Palladium). 53 patients received additional hormone therapy. According to T-stage, Gleason Score and PSA, patients were divided into three risk groups (low, intermediate and high risk). Late gastrointestinal and genitourinary side effects and biochemical disease-free survival were evaluated. The patients were followed up at a median time of 28 months (3-88 months). The median patient age was 67.5 years (47-79 years). The distribution of low, intermediate and high risk group patients was 63 %, 35 % and 2 %. The 2-year actuarial rates of late Grade = 2 gastrointestinal and genitourinary side effects were 5 % and 65 %. The 2-year biochemical disease-free survival rate was 88% (all patients), 90% (low risk) and 88 % (intermediate risk), respectively. Multivariate analysis demonstrated T-stage (p = 0.03), PSA (p 0.02) and patient age (p = 0.02) to be significant factors influencing biochemical disease-free survival. Ultrasound guided transperineal seed implantation in patients with low-risk prostate cancer is an additional treatment option showing promising results. (author)