Can SBRT be considered for high risk prostate cancer?

There are many ways to address this question:

1. The academic "letter of the law" purist: "If a patient population was included within a clinical trial then the trial results apply to them. Subset analyses are hypothesis-generating."

By this logic: HYPO-RT PC enrolled about 11% high-risk disease and showed that with ultra-hypofractionation there is no difference in tumor control or late toxicity. Ultra-hypofrac a standard of care (at least 7 fx).

2. The academic "but what about that subgroup": "Yes...

As someone who does actively enroll patients on a trial investigating SBRT for high risk prostate cancer, I do not think there are enough data available to support treating high risk prostate cancer with SBRT outside of a clinical trial. Patients with high risk prostate cancer have multiple, potentially curative options available to them (surgery, EBRT with long-term ADT, EBRT + BT + ADT), and thus to substitute a known curative option with an investigational option outside the context of a stud...

I agree 100% with Dr. @Dr. First Last. We shouldn't substitute an investigational option off-trial when we already have multiple effective, safe options. My hope is that SBRT will become a standard for high-risk localized prostate cancer maybe in the near future, but for now we're not there yet, and definitely not with the confounder of whether or not to include pelvic nodes.

Regarding Dr. @Dr. First Last's point 4, I believe there is value to late toxicity data beyond 5 years. A common complain...