KEY POINTS
- The updated DEGRO expert statement reviewed three randomized phase III trials with at least 5 years of follow-up: HYPO-RT-PC, PACE-B, and a smaller proton therapy trial.
- In HYPO-RT-PC, 42.7 Gy in 7 fractions was noninferior to 78 Gy in 39 fractions, with 84% 5-year failure-free survival in both groups.
- In PACE-B, 36.25 Gy in 5 fractions, with a simultaneous integrated boost to 40 Gy, achieved 95.8% freedom from biochemical or clinical failure at 5 years versus 94.6% with conventional or moderate hypofractionation.
- PACE-B showed higher cumulative late grade ≥2 genitourinary toxicity with SBRT (26.9% vs 18.3%; p<0.001), while late gastrointestinal toxicity was similar (10.7% vs 10.2%). Baseline urinary symptoms, IPSS >11, and urinary medication use were associated with greater risk.
- DEGRO considers ultrahypofractionation suitable for selected low- to intermediate-risk patients. Caution is advised after TURP, with suboptimal urinary function or larger prostate volumes; high-quality MRI, MRI–CT fusion, IMRT, daily IGRT, and appropriate motion management are recommended.
CLINICAL TAKEAWAY
Ultrahypofractionation is an evidence-supported routine option for appropriately selected patients with low- to intermediate-risk localized prostate cancer, offering comparable tumor control in five to seven fractions. Its convenience must be balanced against a higher risk of late urinary toxicity, particularly in patients with baseline urinary dysfunction. Evidence for high-risk disease and integration with androgen deprivation therapy remains less clearly defined.