Radiation dose predicts for biochemical control in intermediate-risk prostate cancer patients treated with low-dose-rate brachytherapy

Int J Radiat Oncol Biol Phys. 2009 Sep 1;75(1):16-22. doi: 10.1016/j.ijrobp.2008.10.071. Epub 2009 Mar 14.


Purpose: To evaluate the influence of patient- and treatment-related factors on freedom from biochemical failure (FFbF) in patients with intermediate-risk prostate cancer.

Methods and materials: From a prospectively collected database of 2250 men treated at Mount Sinai Hospital from 1990 to 2004 with low-dose-rate brachytherapy for prostate cancer, 558 men with either one or more intermediate-risk features (prostate-specific antigen [PSA] level 10-20 ng/mL, Gleason score 7, or Stage T2b) were identified who had a minimum follow-up of 24 months and postimplant CT-based dosimetric analysis. Biologically effective dose (BED) values were calculated to compare doses from different isotopes and treatment regimens. Patients were treated with brachytherapy with or without hormone therapy and/or external-beam radiotherapy. Patient- and treatment-related factors were analyzed with respect to FFbF. The median follow-up was 60 months (range, 24-167 months). Biochemical failure was defined according to the Phoenix definition. Univariate analyses were used to determine whether any variable was predictive of FFbF. A two-sided p value of <0.05 was considered significant.

Results: Overall, the actuarial FFbF at 10 years was 86%. Dose (BED <150 Gy(2) vs. >or=150 Gy(2)) was the only significant predictor of FFbF (p < 0.001). None of the other variables (PSA, external-beam radiotherapy, Gleason score, treatment type, hormones, stage, and number of risk factors) was found to be a statistically significant predictor of 10-year FFbF.

Conclusions: Radiation dose is an important predictor of FFbF in intermediate-risk prostate cancer. Treatment should continue to be individualized according to presenting disease characteristics until results from Radiation Therapy Oncology Group trial 0232 become available.

MeSH terms

  • Analysis of Variance
  • Androgen Antagonists / therapeutic use
  • Anilides / therapeutic use
  • Antineoplastic Agents, Hormonal / therapeutic use
  • Biopsy
  • Brachytherapy / methods*
  • Flutamide / therapeutic use
  • Follow-Up Studies
  • Goserelin / therapeutic use
  • Humans
  • Iodine Radioisotopes / therapeutic use
  • Leuprolide / therapeutic use
  • Male
  • Nitriles / therapeutic use
  • Palladium / therapeutic use
  • Prostate / pathology
  • Prostate-Specific Antigen / blood*
  • Prostatic Neoplasms / blood
  • Prostatic Neoplasms / drug therapy
  • Prostatic Neoplasms / pathology
  • Prostatic Neoplasms / radiotherapy*
  • Radioisotopes / therapeutic use
  • Radiotherapy Dosage
  • Relative Biological Effectiveness
  • Tosyl Compounds / therapeutic use
  • Treatment Failure


  • Androgen Antagonists
  • Anilides
  • Antineoplastic Agents, Hormonal
  • Iodine Radioisotopes
  • Nitriles
  • Radioisotopes
  • Tosyl Compounds
  • Goserelin
  • Palladium
  • Flutamide
  • bicalutamide
  • Prostate-Specific Antigen
  • Leuprolide