The two recent studies that are usually referenced are COMPPARE and PARTIQoL. Both studies indicated similar tumor control rates and patient-reported quality of life outcomes.

What’s important to understand about clinical trials is that they’re great at providing a “big picture” large population view of what to expect from treatments. Since they represent thousands of patients, insurance companies need that, hospitals need that, governments need that, etc., because they all need to plan and estimate how to allocate resources (dollars, equipment, staffing, etc.) based on the averages……not the best; not the worst.

But for what a specific patient (you or me) should expect our outcome should be from a particular treatment, they’re nearly worthless - without knowing how someone with a specific diagnosis, risk factors, comorbidities, regimen compliance, etc. compares to ours. (That applies to all clinical trials, not just these two.)

In my case, I didn’t just go by the no better/no worse large scale outcome. I selectively picked one of the 49 proton centers specializing in proton for my treatments - as it turned out a pediatric center (and a teaching and research center) that also treated prostate cancers (as well as other types) - because I knew that they were experts on hitting pea-sized tumors within the brains of kids without causing peripheral damage; I figured that they could hit a walnut-sized gland within my pelvis, also without causing peripheral damage. But, that also required me to do my part exactly right each and every session exactly the same way (& if I had screwed up, that would’ve caused problems).
=========

Today, 5 years (& 3 weeks later), it’s turned out as well as planned (if not better) - certainly better than either COMPPARE or PARTIQoL indicated that I should expect. But, that required me not shooting just for “no better/no worse” - which was the result of both those two studies.