High dose brachytherapy (real time) in patients with intermediate- or high-risk prostate cancer: technical description and preliminary experience

RESUMEN

Introduction. It has been well documented that the outcome of prostate cancer treatment depends on the dose administered. Hence, techniques have been developed that allow high-dose administration without increasing the complications, e.g. external radiotherapy combined with high-dose radiation (HDR) brachytherapy. In this article we analyse the technique and protocol of real-time HDR brachytherapy together with the preliminary results that support its use. Materials and methods. Between June 1998 and December 2004, 100 patients with adenoma of the prostate were treated with 46 Gy of external irradiation to the pelvis and 2 HDR brachytherapy fractions (each of 1150 cGy) at the end of weeks 1 and 3 of a 5week radiotherapy course. The 1997 American Joint Commission on Cancer (AJCC) system was used to establish disease stage. Patients with intermediate-risk (PSA 10-20 ng/ml or Gleason = 7 or T2c) and high-risk (two intermediate risk factors or PSA > 20 ng/ml or Gleason > 7 or > T2c) without metastases were eligible for the brachytherapy. Biochemical failure was defined according to the American Society for Therapeutic Radiology and Oncology (ASTRO) consensus panel statement. SPSS statistical package was used to quantify survival (Kaplan-Meier method). Toxicity was scored according to RTOG guidelines. Results. The mean age of patients was 67 years (range 49-78). Clinical stage was T2a in 22% of the patients, 26% T2b and 52% T3. Initial PSA was = 10 ng/ml in 22% of the patients and > 10 ng/ml in 78%. Median follow-up was 28 months (range 12-79). The 5-year overall survival and actuarial biochemical control were 99% and 87% respectively. No chronic severe complications were noted. Conclusions. The good results of local control, di-sease-free survival and few complications that the external radiotherapy combined with HDR brachytherapy have shown suggest that the method should be considered as first-choice in the treatment of prostate tumours of high- and intermediate-risk