Top Line: Does moderately hypofractionated prostate radiation hold up against standard fractionation after >10 years?
The Study: RTOG 0415 helped establish moderate hypofractionation using 70 Gy in 28 fractions as a widely used regimen for prostate cancer. Here we have long-term results from 0415. As a reminder, over 1000 patients with low risk prostate cancer were randomized to receive 70 Gy in 28 fractions or 73.8 Gy in 41 fractions. The dose constraints in the hypofrac arm were somewhat loose, and most of us now use much more strict constraints. At the 12 year mark, disease free survival was deemed non-inferior with hypofractionation (61.8% v 56.1%). Both biochemical failure (9.9% v 17%) and local progression (0.6% v 4.7%) were significantly lower with hypofractionation. There were no significant differences in late grade 3+ GI (4.4% HFX v 3.2%) or GU (4.2% HFX v 3.4%) toxicity. The rates of late grade 2+ GI toxicity were 23.8% v 15.4%, and the rates of late grade 2+ GU toxicity were 33.4% v 26.8%.
TBL: Long term followup of RTOG 0415 confirms the non-inferiority of moderate hypofractionation and even suggests better biochemical control compared to a dose of 73.8 Gy in 41 fractions for low risk disease. | Lee, J Clin Oncol 2024
The Study: RTOG 0415 helped establish moderate hypofractionation using 70 Gy in 28 fractions as a widely used regimen for prostate cancer. Here we have long-term results from 0415. As a reminder, over 1000 patients with low risk prostate cancer were randomized to receive 70 Gy in 28 fractions or 73.8 Gy in 41 fractions. The dose constraints in the hypofrac arm were somewhat loose, and most of us now use much more strict constraints. At the 12 year mark, disease free survival was deemed non-inferior with hypofractionation (61.8% v 56.1%). Both biochemical failure (9.9% v 17%) and local progression (0.6% v 4.7%) were significantly lower with hypofractionation. There were no significant differences in late grade 3+ GI (4.4% HFX v 3.2%) or GU (4.2% HFX v 3.4%) toxicity. The rates of late grade 2+ GI toxicity were 23.8% v 15.4%, and the rates of late grade 2+ GU toxicity were 33.4% v 26.8%.
TBL: Long term followup of RTOG 0415 confirms the non-inferiority of moderate hypofractionation and even suggests better biochemical control compared to a dose of 73.8 Gy in 41 fractions for low risk disease. | Lee, J Clin Oncol 2024