The Headline: At five years there were more adverse bladder effects with hypofractionated prostate fossa RT than with conventional fractionation.
The Study: Despite encouraging initial results with 62.5 Gy in 25 fractions prostate fossa radiation in GU003, there has been caution in adopting the regimen while awaiting longer term results. Recall that 296 patients receiving adjuvant/salvage prostate fossa RT were randomized to 62.5 Gy in 25 fractions or 66.6 Gy in 37 fractions. At 5 years, grade 3 events were higher with hypofractionation (16% v 7%), which were largely driven by urinary events, particularly cystitis (7% v 0%) and hematuria (6% v 0.7%). However, there were no differences in patient reported outcomes, and no higher grade events. There was no difference in biochemical failure with hypofractionation vs conventional fractionation (21% v 18%).
TBL: Late grade 3 GU adverse effects were higher after moderately hypofractionated prostate fossa RT, but there were no differences in treatment outcomes or patient reported outcomes. | Buyyounousky, ASTRO 2026
The Study: Despite encouraging initial results with 62.5 Gy in 25 fractions prostate fossa radiation in GU003, there has been caution in adopting the regimen while awaiting longer term results. Recall that 296 patients receiving adjuvant/salvage prostate fossa RT were randomized to 62.5 Gy in 25 fractions or 66.6 Gy in 37 fractions. At 5 years, grade 3 events were higher with hypofractionation (16% v 7%), which were largely driven by urinary events, particularly cystitis (7% v 0%) and hematuria (6% v 0.7%). However, there were no differences in patient reported outcomes, and no higher grade events. There was no difference in biochemical failure with hypofractionation vs conventional fractionation (21% v 18%).
TBL: Late grade 3 GU adverse effects were higher after moderately hypofractionated prostate fossa RT, but there were no differences in treatment outcomes or patient reported outcomes. | Buyyounousky, ASTRO 2026