Copyright © 2008 Elsevier Inc. All rights reserved.
Clinical Investigation
Long-Term Results of Conformal Radiotherapy for Prostate Cancer: Impact of Dose Escalation on Biochemical Tumor Control and Distant Metastases-Free Survival Outcomes
Biochemical failure developed in 20 (21%) of the 96 men 60 years or younger, which was similar to the 22%failure rate observed in 644 patients older than 60. The 5 and 7-year biochemical disease-free survival rates were 82%and 79%in younger men, and 79%and 78%in older men, respectively (p = 0.48). For younger patients who received 81 Gy or greater, the 7-year prostate specific antigen relapse-free survival rates for favorable, intermediate and unfavorable risk patients were 96%, 87%and 50%, respectively. Multivariate analysis revealed that among patients 60 years or younger the most important predictor of biochemical relapse was radiation doses less than 75.6 Gy followed by Gleason score greater than 7.
Men with prostate cancer 60 years or younger treated with high dose radiotherapy have an excellent biochemical outcome and fare as well as older patients. The use of conventional dose levels in patients 60 years or younger was associated with an 8-fold increase in the biochemical relapse rate and these doses should not be considered appropriate for the treatment of localized prostate cancer.
Long European Urology |
Long European Urology, Volume 53, Issue 6, June 2008, Pages 1172-1179 Michael J. Zelefsky, Yoshiya Yamada, Marisa A. Kollmeier, Alison M. Shippy, Michelle A. Nedelka Abstract ObjectiveTo report the long-term tumor control and survival outcomes after conformal external-beam radiotherapy for patients with clinical stage T3 prostate cancer.MethodsBetween 1988 and 2000, 296 patients with clinical stage T3 prostate cancer were treated with three-dimensional conformal radiotherapy and intensity-modulated radiotherapy. Of these, 130 patients (44%) had stage T3a (extracapsular extension without seminal vesicle involvement [SVI]) and 166 patients (56%) had stage T3b disease (SVI). Prior to radiotherapy, 189 patients (43%) were treated with short-course androgen-deprivation therapy (ADT). The median follow-up time was 8 yr. ResultsThe 5- and 10-yr prostate-specific antigen (PSA) relapse-free survival (PRFS) outcomes for stage T3a tumors were 69%and 44%, respectively. The corresponding PRFS outcomes for T3b tumors were 49%and 32%(p = 0.005). Despite the presence of locally advanced disease, the 5- and 10-yr local progression-free survival (LPFS) outcomes for all patients were 87%and 83%. Among patients who received ≥8100 cGy and ADT, the 5- and 10-yr local control rates were 96%and 88%. The 5- and 10-yr distant metastases-free survival (DMFS) outcomes for stage T3a tumors were 85%and 73%. The corresponding DMFS outcomes for T3b tumors were 49%and 32%(p = 0.005). Multivariate analysis demonstrated that ADT conferred a 7-fold risk reduction for local failure. Pretreatment PSA levels and the presence of SVI on clinical staging were important predictors of distant metastases. ConclusionsConformal radiotherapy for T3 prostate cancer is associated with excellent tumor control and survival outcomes. These results are at least comparable to reported outcomes from surgical series for T3 disease and substantiate the role of radiotherapy as the standard management option for locally advanced stage prostate cancer. Purchase PDF (311 K) |
Multi International Journal of Radiation Oncology*Biology*Phy... |
Multi International Journal of Radiation Oncology*Biology*Physics, Volume 67, Issue 2, 1 February 2007, Pages 327-333 Michael J. Zelefsky, Deborah A. Kuban, Larry B. Levy, Louis Potters, David C. Beyer, John C. Blasko, Brian J. Moran, Jay P. Ciezki, Anthony L. Zietman, Thomas M. Pisansky, Mohamed Elshaikh, Eric M. Horwitz Abstract Purpose: To assess long-term prostate-specific antigen (PSA) outcome after permanent prostate brachytherapy (BT) and identify predictors of improved disease-free survival. Methods and Materials: Eleven institutions combined data on 2,693 patients treated with permanent interstitial BT monotherapy for T1–T2 prostate cancer. Of these patients, 1,831 (68%) were treated with I-125 (median dose, 144 Gy) and 862 (32%) were treated with Pd-103 (median dose, 130 Gy). Criteria for inclusion were: available pre-BT PSA, BT ≥5 years before data submission, BT between 1988–1998, and no androgen deprivation before failure. The median follow-up was 63 months. Results: Among patients where the I-125 dose to 90%of the prostate (D90) was ≥130 Gy, the 8-year PSA relapse-free survival (PRFS) was 93%compared with 76%for those with lower D90 dose levels (p < 0.001). A multivariable analysis identified tumor stage (p = 0.002), Gleason score (p < 0.001), pretreatment PSA level (p < 0.001), treatment year (p = 0.001), and the isotope used (p = 0.004) as pretreatment and treatment variables associated with PRFS. When restricted to patients with available postimplantation dosimetric information, D90 emerged as a significant predictor of biochemical outcome (p = 0.01), and isotope was not significant. The 8-year PRFS was 92%, 86%, 79%, and 67%, respectively, for patients with PSA nadir values of 0–0.49, 0.5–0.99, 1.0–1.99, and >2.0 ng/mL (p < 0.001). Among patients free of biochemical relapse at 8 years, the median nadir level was 0.1 ng/mL, and 90%of these patients achieved a nadir PSA level <0.6 ng/mL. Conclusions: Outcome after permanent BT for prostatic cancer relates to tumor stage, Gleason score, pretreatment PSA, BT year, and post-BT dosimetric quality. PSA nadir ≤0.5 ng/mL was particularly associated with durable long-term PSA disease-free survival. The only controllable factor to impact on long-term outcome was the D90 which is a reflection of implant quality. Purchase PDF (679 K) |
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Long-Term Results of Conformal Radiotherapy for Prostate Cancer: Impact of Dose Escalation on Biochemical Tumor Control and Distant Metastases-Free Survival Outcomes