High-dose-rate brachytherapy as a monotherapy for favorable-risk prostate cancer: a Phase II trial

Int J Radiat Oncol Biol Phys. 2012 Apr 1;82(5):1889-96. doi: 10.1016/j.ijrobp.2010.09.006. Epub 2011 May 6.

Abstract

Purpose: There are multiple treatment options for favorable-risk prostate cancer. High-dose-rate (HDR) brachytherapy as a monotherapy is appealing, but its use is still investigational. A Phase II trial was undertaken to explore the value of such treatment in low-to-intermediate risk prostate cancer.

Methods and materials: This was a single-institution, prospective study. Eligible patients had low-risk prostate cancer features but also Gleason scores of 7 (51% of patients) and stage T2b to T2c cancer. Treatment with HDR brachytherapy with a single implant was administered over 2 days. One of four fractionation schedules was used in a dose escalation study design: 3 fractions of 10, 10.5, 11, or 11.5 Gy. Patients were assessed with the Common Terminology Criteria for Adverse Events version 2.0 for urinary toxicity, the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer scoring schema for rectal toxicity, and the Expanded Prostate Cancer Index Composite (EPIC) questionnaire to measure patient-reported health-related quality of life. Biochemical failure was defined as a prostate-specific antigen (PSA) nadir plus 2 ng/ml.

Results: Between 2003 and 2008, 79 patients were enrolled. With a median follow-up of 39.5 months, biochemical relapse occurred in 7 patients. Three- and 5-year actuarial biochemical control rates were 88.4% (95% confidence interval [CI], 78.0-96.2%) and 85.1% (95% CI, 72.5-94.5%), respectively. Acute grade 3 urinary toxicity was seen in only 1 patient. There was no instance of acute grade 3 rectal toxicity. Rates of late grade 3 rectal toxicity, dysuria, hematuria, urinary retention, and urinary incontinence were 0%, 10.3%, 1.3%, 9.0%, and 0%, respectively. No grade 4 or greater toxicity was recorded. Among the four (urinary, bowel, sexual, and hormonal) domains assessed with the EPIC questionnaire, only the sexual domain did not recover with time.

Conclusions: HDR brachytherapy as a monotherapy for favorable-risk prostate cancer, administered using a single implant over 2 days, is feasible and has acceptable acute and late toxicities. Further follow-up is still required to better evaluate the efficacy of such treatment.

Publication types

  • Clinical Trial, Phase II

MeSH terms

  • Adenocarcinoma / blood
  • Adenocarcinoma / pathology
  • Adenocarcinoma / psychology
  • Adenocarcinoma / radiotherapy*
  • Aged
  • Brachytherapy / adverse effects
  • Brachytherapy / methods*
  • Erectile Dysfunction / etiology
  • Feasibility Studies
  • Humans
  • Male
  • Middle Aged
  • Neoplasm Grading
  • Neoplasm Recurrence, Local / blood
  • Neoplasm Staging
  • Prospective Studies
  • Prostate-Specific Antigen / blood
  • Prostatic Neoplasms / blood
  • Prostatic Neoplasms / pathology
  • Prostatic Neoplasms / psychology
  • Prostatic Neoplasms / radiotherapy*
  • Quality of Life
  • Radiation Injuries / complications
  • Radiotherapy Dosage
  • Rectum / radiation effects
  • Risk
  • Urination Disorders / etiology

Substances

  • Prostate-Specific Antigen