Ultra-Hypofractionated Radiotherapy Shows Promise in Prostate Cancer Treatment

Strategic Insights -

A recent study presented at the annual meeting of the European Society for Radiotherapy and Oncology found that ultra-hypofractionated (UHF) radiotherapy delivered over two weeks is noninferior to conventionally fractionated (CF) radiotherapy delivered over eight weeks for localized prostate cancer up to 10 years. The study included 1,180 men with intermediate- to high-risk localized prostate cancer, who were randomly assigned to either UHF (42.7 Gy in seven fractions over 2.5 weeks) or CF radiotherapy (78.0 Gy in 39 fractions over eight weeks). The results showed that UHF radiotherapy was noninferior to CF radiotherapy in terms of failure-free survival (FFS) and overall survival, with a significant difference in favor of UHF at 10 years. The study also found that UHF radiotherapy had similar late genitourinary and gastrointestinal toxicity as CF radiotherapy.

Key Takeaways:

  • Ultra-hypofractionated (UHF) radiotherapy delivered over two weeks was noninferior to conventionally fractionated (CF) radiotherapy delivered over eight weeks for localized prostate cancer up to 10 years.
  • The per-protocol population included 1,180 men who were randomly assigned to UHF (42.7 Gy in seven fractions over 2.5 weeks) or CF radiotherapy (78.0 Gy in 39 fractions over eight weeks).
  • The researchers found that 178 and 205 primary outcome events (failure-free survival [FFS]) occurred in the UHF and CF groups, respectively, at a median follow-up of 10.6 years.
  • The adjusted hazard ratio for FFS was 0.84 (95% confidence interval, 0.69 to 1.03), confirming noninferiority.
  • Up to approximately six years, the Kaplan-Meier curves were similar, but they diverged after which they favored UHF.
  • At 10 years, the difference in FFS was significant.
  • The two groups had similar overall survival, which was 81 and 79% in the UHF and CF groups, respectively, at 10 years.
  • The cumulative incidence of prostate cancer-specific death was identical at 4% at 10 years.
  • Freedom from androgen-deprivation therapy did not differ significantly between the groups and was 77 and 75% in the UHF and CF groups, respectively, at 10 years.
  • There were no statistically significant differences in late genitourinary and gastrointestinal toxicity between the groups.
  • The study's findings suggest that delivering fewer, higher doses over a shorter period works just as well as the standard approach in real-world clinical practice.

Statistics:

  • 1,180 men were included in the per-protocol population.
  • 178 primary outcome events (failure-free survival [FFS]) occurred in the UHF group at a median follow-up of 10.6 years.
  • 205 primary outcome events (FFS) occurred in the CF group at a median follow-up of 10.6 years.
  • The adjusted hazard ratio for FFS was 0.84 (95% confidence interval, 0.69 to 1.03).
  • 81% of men in the UHF group had overall survival at 10 years.
  • 79% of men in the CF group had overall survival at 10 years.
  • The cumulative incidence of prostate cancer-specific death was 4% at 10 years.

Sources:

  • European Society for Radiotherapy and Oncology
  • Skåne University Hospital in Lund, Sweden