12-year outcomes following permanent prostate brachytherapy in patients with clinically localized prostate cancer.

PURPOSE: We reviewed the outcomes in men treated with permanent prostate brachytherapy (PPB). MATERIAL AND METHODS: A total of 1,449 consecutive patients with a mean age of 68 years treated with PPB between 1992 and 2000 and mean pretreatment prostate specific antigen (PSA) 10.1 ng/ml were included in this study. Of the patients 55% presented with Gleason 6 tumors and 28% had Gleason 7 disease. A total of 400 patients (27%) were treated with neoadjuvant hormones and 301 (20%) were treated in combination with external radiation plus PPB. Several biochemical freedom from recurrence (BFR) definitions were determined. Statistical analysis consisted of log rank testing, Kaplan-Meier estimates and Cox regression analysis. RESULTS: Median followup was 82 months with 39 patients at risk at for 144 months. Overall and disease specific survival at 12 years was 81% and 93%, respectively. The 12-year BFR was 81%, 78%, 74% and 77% according to the American Society for Therapeutic Radiology and Oncology (ASTRO), ASTRO-Kattan, ASTRO-Last Call and Houston definitions, respectively. The 12-year ASTRO-Kattan BFR using risk stratification was 89%, 78% and 63% in patients at low, intermediate and high risk, respectively (p = 0.0001). Multivariate analysis identified the dose that 90% of the target volume received (p <0.0001), pretreatment PSA (p = 0.001), Gleason score (p = 0.002), the percent positive core biopsies (p = 0.037), clinical stage (p = 0.689), the addition of hormones (p = 0.655) and the addition of external radiation (p = 0.724) for predicting BFR-ASTRO. Five-year disease specific survival was 44% in patients with a PSA doubling time of less than 12 months vs 88% in those with a PSA doubling time of 12 months or greater (p = 0.0001). CONCLUSIONS: PPB offers acceptable 12-year BFR in patients who present with clinically localized prostate cancer. Implant dosimetry continues as an important predictor for BFR, while the addition of adjuvant therapies such as hormones and external radiation are insignificant. In patients who experience biochemical failure it appears that PSA doubling time is an important predictor of survival.

Is there a role for postimplant dosimetry after real-time dynamic permanent prostate brachytherapy?

PURPOSE: To evaluate the correlation of real-time dynamic prostate brachytherapy (RTDPB) dosimetry and traditional postimplant dosimetry for permanent prostate brachytherapy. METHODS AND MATERIALS: A total of 164 patients underwent RTDPB for clinically confined prostate cancer. Of these 164 patients, 45 were implanted with 103Pd and 119 with 125I. Additionally, 44 patients underwent combined external beam radiotherapy and brachytherapy and 120 patients underwent brachytherapy alone. The postimplant dosimetry with computed tomography was performed at 4 weeks and compared with the RTDPB dose plan using the intraclass correlation coefficient. The millicurie/gram of the prostate volume and the percentage of the minimal dose to 90% of the prostate relative to the prescribed implant dose (D90%) of the RTDPB patients was compared with 400 patients treated with a free-seed technique. RESULTS: The mean D90% achieved in the operating room and on the 3-week dose plan was 109% (range, 93-139%) and 105% (range, 88-140), respectively. The mean percentage of prostate volume receiving 100% of the prescribed minimal peripheral dose (V100) achieved in the operating room and on the 3-week dose plan was 93% (range, 78-98%) and 91% (range, 64-98%), respectively. The intraclass correlation coefficient for each calculated relationship was 0.586 for D90 (p<0.001), 1.19 for V100 (p=0.135), 0.692 for the urethral D90 (p<0.001), 0.602 for the maximal rectal dose (p<0.001), 0.546 for D90 with 125I (p<0.001), and 0.565 for D90 with 103Pd (p<0.001). A 12% decrease was noted in the millicurie/gram of the isotope, with a 2.5% increase in the D90 comparing RTDPB and the free-seed technique. CONCLUSION: The results of this study demonstrated a correlation between the dose assessment obtained intraoperatively and postoperatively at 3 weeks. With reliable dose data available in the operating room, our results question the need for routine postimplant dose studies. Furthermore, patients treated with RTDPB received less radioactivity per gram of the prostate with a corresponding small increase in the D90. Future analyses will assess variations in the inverse dose planning rules and the clinical correlation of patients undergoing RTDPB vs. older techniques for toxicity and biochemical outcomes.

12-year outcomes following permanent prostate brachytherapy in patients with clinically localized prostate cancer.

PURPOSE: We reviewed the outcomes in men treated with permanent prostate brachytherapy (PPB). MATERIAL AND METHODS: A total of 1,449 consecutive patients with a mean age of 68 years treated with PPB between 1992 and 2000 and mean pretreatment prostate specific antigen (PSA) 10.1 ng/ml were included in this study. Of the patients 55% presented with Gleason 6 tumors and 28% had Gleason 7 disease. A total of 400 patients (27%) were treated with neoadjuvant hormones and 301 (20%) were treated in combination with external radiation plus PPB. Several biochemical freedom from recurrence (BFR) definitions were determined. Statistical analysis consisted of log rank testing, Kaplan-Meier estimates and Cox regression analysis. RESULTS: Median followup was 82 months with 39 patients at risk at for 144 months. Overall and disease specific survival at 12 years was 81% and 93%, respectively. The 12-year BFR was 81%, 78%, 74% and 77% according to the American Society for Therapeutic Radiology and Oncology (ASTRO), ASTRO-Kattan, ASTRO-Last Call and Houston definitions, respectively. The 12-year ASTRO-Kattan BFR using risk stratification was 89%, 78% and 63% in patients at low, intermediate and high risk, respectively (p = 0.0001). Multivariate analysis identified the dose that 90% of the target volume received (p <0.0001), pretreatment PSA (p = 0.001), Gleason score (p = 0.002), the percent positive core biopsies (p = 0.037), clinical stage (p = 0.689), the addition of hormones (p = 0.655) and the addition of external radiation (p = 0.724) for predicting BFR-ASTRO. Five-year disease specific survival was 44% in patients with a PSA doubling time of less than 12 months vs 88% in those with a PSA doubling time of 12 months or greater (p = 0.0001). CONCLUSIONS: PPB offers acceptable 12-year BFR in patients who present with clinically localized prostate cancer. Implant dosimetry continues as an important predictor for BFR, while the addition of adjuvant therapies such as hormones and external radiation are insignificant. In patients who experience biochemical failure it appears that PSA doubling time is an important predictor of survival.