10-year experience with I-125 prostate brachytherapy at the Princess Margaret Hospital: results for 1,100 patients

Int J Radiat Oncol Biol Phys. 2011 Aug 1;80(5):1323-9. doi: 10.1016/j.ijrobp.2010.04.038. Epub 2010 Aug 1.

Abstract

Purpose: To report outcomes for 1,111 men treated with iodine-125 brachytherapy (BT) at a single institution.

Methods and materials: A total of 1,111 men (median age, 63) were treated with iodine-125 prostate BT for low- or intermediate-risk prostate cancer between March 1999 and November 2008. Median prostate-specific antigen (PSA) level was 5.4 ng/ml (range, 0.9-26.1). T stage was T1c in 66% and T2 in 34% of patients. Gleason score was 6 in 90.1% and 7 or 8 in 9.9% of patients. Neoadjuvant hormonal therapy (2-6 months course) was used in 10.1% of patients and combined external radiotherapy (45 Gy) with BT (110 Gy) in 4.1% (n = 46) of patients. Univariate and multivariate Cox proportional hazards were used to determine predictors of failure.

Results: Median follow-up was 42 months (range, 6-114), but for biochemical freedom from relapse, a minimum PSA test follow-up of 30 months was required (median 54; n = 776). There were 27 failures, yielding an actuarial 7-year disease-free survival rate of 95.2% (96 at risk beyond 84 months). All failures underwent repeat 12-core transrectal ultrasound -guided biopsies, confirming 8 local failures. On multivariate analysis, Gleason score was the only independent predictor of failure (p = 0.001; hazard ratio, 4.8 (1.9-12.4). Median International Prostate Symptom score from 12 to 108 months ranged between 3 and 9. Of the men reporting baseline potency, 82.8% retained satisfactory erectile function beyond 5 years.

Conclusion: Iodine-125 prostate BT is a highly effective treatment option for favorable- and intermediate-risk prostate cancer and is associated with maintenance of good urinary and erectile functions.

MeSH terms

  • Adenocarcinoma / blood
  • Adenocarcinoma / mortality
  • Adenocarcinoma / pathology
  • Adenocarcinoma / radiotherapy*
  • Aged
  • Aged, 80 and over
  • Brachytherapy / adverse effects
  • Brachytherapy / methods*
  • Disease-Free Survival
  • Humans
  • Iodine Radioisotopes / therapeutic use*
  • Male
  • Middle Aged
  • Neoadjuvant Therapy / methods
  • Neoplasm Staging
  • Ontario
  • Penile Erection / physiology
  • Proportional Hazards Models
  • Prospective Studies
  • Prostate
  • Prostate-Specific Antigen / blood
  • Prostatic Neoplasms / blood
  • Prostatic Neoplasms / mortality
  • Prostatic Neoplasms / pathology
  • Prostatic Neoplasms / radiotherapy*
  • Radiotherapy Dosage
  • Urination Disorders / drug therapy

Substances

  • Iodine Radioisotopes
  • Prostate-Specific Antigen