The take-home message of the study findings from the Fox Chase trial reported at the 53rd ASTRO Annual Meeting plenary session supports the use of hypofractionated intensity-modulated radiotherapy as a more convenient and cost-effective alternative than conventional IMRT, according to formal discussant of this trial Patrick Kupelian, MD, of UCLA Jonsson Comprehensive Cancer Center.
In another positive randomized trial of hypofractionated IMRT for high-risk prostate cancer,1 the hypofractionated schedule was superior to the conventional schedule in terms of freedom from biochemical failure. However, the hypofractionated arm consisted of 62 Gy/20 fractions (3.1 Gy/fraction), whereas in the Fox Chase trial, it was 70.2 Gy in 2.0 fractions. “You might need higher doses per fraction to see changes or differences in efficacy,” Dr. Kupelian speculated.
The issue of late toxicity has been a major concern with hypofractionated IMRT. “A few years back, the concern was always rectal toxicity; amazingly, the events have been very few on this trial,” admitted Dr. Kupelian. Gastrointestinal toxicity was not a concern in this trial, and genitourinary toxicity consisted mostly of grade 2 events. Therefore, echoing the sentiments of Allan Pollack, MD, who presented the Fox Chase trial, Dr. Kupelian considers pretreatment urinary status to be an important predictor of genitourinary toxicity, more so with hypofractionated IMRT than with conventional IMRT. ■
Disclosure: Dr. Kupelian reported no potential conflicts of interest.
1. Arcangeli G, Saracino B, Gomellini S, et al: A prospective phase III randomized trial of hypofractionation versus conventional fractionation in patients with high-risk prostate cancer. Int J Radiat Oncol Biol Phys 78:11-18, 2010.