I personally await the 35-year followup data (median, not projected) from these hypofractionation studies, because I truly believe in following the evidence. Yes, I know there is no high-grade randomized evidence for 81 Gy, IGRT, IMRT over 3D, and yes I do these things routinely. I mean, I would have waited for 35 years of followup for that stuff too but the billing codes came first so what was I supposed to do?
Particularly, I'm worried about a minor risk of increased late toxicity because the 50-year followup data for dose escalation has shown me that this is a true risk, and I quote that data religiously to patients. I really spend the time to explain to them that we are talking about absolute risks of severe toxicities that are still below 10%. Specifically, for patients who are 75-80 years old, I think we really need the long-term followup data before I will even consider hypofractionation with a 28 fraction course.
Once this data is available in 2040 or so, I think we can start a phase III trial of 28 fractions versus 27 fractions, and I can posthumously recommend 27 fractions to patients when I am confident about the quantified risk of urethral strictures.