Clinical outcome in patients with prostate cancer treated with external beam radiotherapy and high dose-rate iridium 192 brachytherapy boost: A 6-year follow-up

Abstract

To report the long-term results for treatment of localized carcinoma of the prostate using high dose rate (HDR) brachytherapy, conformal external beam radiotherapy (3D EBRT) and neo-adjuvant hormonal therapy (TAB). From 1998 through 1999, 154 patients with localized prostate cancer were entered in the trial. Biologically no evidence of disease (bNED) was defined at PSA levels < 2 µg/l. In order to compare the results of this treatment with other treatment modalities, the patient's pre-treatment data were used to calculate the estimated 5-year PSA relapse free survival using Kattan's nomograms for radical prostatectomy (RP) and 3D EBRT. After 6 years of follow-up, 129 patients remain alive. The actual 5-year relapse-free survival is 84%. None of the patients demonstrated clinical signs of local recurrence. The median PSA at follow-up among the relapse-free patients was 0.05 µg/l. Among the 80 patients who presented with clinical stage T3 tumours, 55 (68%) were relapse-free. The expected 5-year relapse-free survival using nomograms for RP and 3D EBRT was 54% and 70%, respectively. Late rectal toxicity RTOG grade 3 occurred in 1% of the patients. Late urinary tract toxicity RTOG grade 3 developed in 4% of the patients. Combined treatment, utilizing HDR, 3D EBRT and TAB, produces good clinical results. Rectal toxicity is acceptable. Urinary tract toxicity, most likely can be explained by the fact that during the first years of this treatment, no effort was made to localize the urethra, which was assumed to be in the middle of the prostate.