Clinical Outcomes of Dose-escalated Radiotherapy for Localised Prostate Cancer: A Single-institution Experience

In Vivo. 2020 Mar-Apr;34(2):757-765. doi: 10.21873/invivo.11835.

Abstract

Background/aim: To report the outcomes of patients with prostate cancer treated with dose-escalated radiotherapy over a 15-year period at our Institution.

Patients and methods: Patients with biopsy-proven cT1-4N0M0 disease who received radical external beam radiotherapy (EBRT) were reviewed. The endpoints were 5-year overall survival (OS), freedom from biochemical failure (FFBF) and late treatment toxicities.

Results: A total of 236 patients were eligible. Median follow-up was 70 months. Low-, intermediate- and high-risk disease was found in 9%; 29% and 62% of patients, respectively. The median radiation dose was 73.8 Gy. Overall 42% of patients had dose escalation to >74 Gy. Five-year OS and FFBF were 95.2%/81.6%/75.4% and 95.0%/98.0%/82.0% for low-/intermediate-/high-risk patients, respectively. Dose escalation to >74 Gy did not improve FFBF (hazard ratio=0.97, 95% confidence intervaI=0.43-2.19, p=0.93) and was associated with a 4.3-fold increase in the odds of grade 3 or more rectal bleeding (p<0.01).

Conclusion: Dose escalation to >74 Gy did not improve OS or FFBF but was associated with a higher rate of grade 3 or more rectal haemorrhage.

Keywords: Prostate cancer; androgen deprivation therapy; dose escalation; proctitis; radiotherapy; toxicity.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Androgen Antagonists / therapeutic use
  • Dose-Response Relationship, Radiation
  • Hemorrhage / etiology
  • Humans
  • Kaplan-Meier Estimate
  • Logistic Models
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Outcome Assessment, Health Care / methods
  • Outcome Assessment, Health Care / statistics & numerical data
  • Prostate-Specific Antigen / analysis
  • Prostatic Neoplasms / diagnosis
  • Prostatic Neoplasms / drug therapy
  • Prostatic Neoplasms / radiotherapy*
  • Radiotherapy / adverse effects
  • Radiotherapy / methods
  • Rectum / pathology
  • Rectum / radiation effects

Substances

  • Androgen Antagonists
  • Prostate-Specific Antigen