Updated results of high-dose rate brachytherapy and external beam radiotherapy for locally and locally advanced prostate cancer using the RTOG-ASTRO phoenix definition

ABSTRACT

PURPOSE: To evaluate the prognostic factors for patients with local or locally advanced prostate cancer treated with external beam radiotherapy (RT) and high dose rate brachytherapy (HDR) according to the RTOG-ASTRO Phoenix Consensus Conference. MATERIALS AND METHODS: The charts of 209 patients treated between 1997 and 2005 with localized RT and HDR as a boost at the Department of Radiation Oncology, AC Camargo Hospital, Sao Paulo, Brazil were reviewed. Clinical and treatment parameters i.e. patient's age, Gleason score, clinical stage, initial PSA (iPSA), risk group (RG) for biochemical failure, doses of RT and HDR were evaluated. Median age and median follow-up time were 68 and 5.3 years, respectively. Median RT and HDR doses were 45 Gy and 20 Gy. RESULTS: Disease specific survival (DSS) at 3.3 year was 94.2 percent. Regarding RG, for the LR (low risk), IR (intermediate risk) and HR (high risk), the DSS rates at 3.3 years were 91.5 percent, 90.2 percent and 88.5 percent, respectively. On univariate analysis prognostic factors related to DSS were RG (p = 0.040), Gleason score ¡Ü 6 ng/mL (p = 0.002), total dose of HDR ¡Ý 20 Gy (p < 0.001) On multivariate analysis the only statistical significant predictive factor for biochemical control (bNED) was the RG, p < 0.001 (CI - 1.147-3.561). CONCLUSIONS: Although the radiation dose administered to the prostate is an important factor related to bNED, this could not be established with statistical significance in this group of patients. To date , in our own experience, HDR associated to RT could be considered a successful approach in the treatment of prostate cancer.