@psychometric, your suggestion is right on! MiraDX PROSTOX tests are another step forward in trying to identify variables that might help PCa patients weigh their treatment options.
I did take the opportunity to take both Prostox tests, (Ultra- for 5 to 7 fraction SBRT and CFRT- for 35-45 fraction Tx). My results were low-intermediate genetic risk (2 on a scale of 5) for late grade 2+ GU Toxicity for both forms of EBRT. As you know, it's MiraDX's hypothesis that there is a subset of patients that are genetically predisposed to radiation toxicities and they may account for a significant portion of grade 3 or higher radiation toxicity side effects. It is still very early in their modeling and data collection. If my memory serves, the sensitivity of their SBRT Test was 65%, meaning that it correctly identified patients that experienced late grade 2 or higher GU toxicity reactions about 2/3's of the time. The specificity of their SBRT Test was better at 79%, meaning that patients like you and I that score low, have about a 4 in 5 chance they won't develop late grade 2 or higher GU toxicity.
2 cautions for others reading this:
- I am a PCa patient sorting through clinical studies to make my own treatment decisions. I am not a doctor.
- It is very early in the Prostox modeling and development. I believe the Prostox Tests shows promise, but MiraDX may have several hundred or a couple thousand data points. Decipher, as a comparison, has over 200,000 whole-transcriptome profiles from patients . For my part, I took the test to see if I was a 'high risk radiation patient' for either SBRT or CFRT. According to MiraDX, a patient can be high risk for SBRT but not for CFRT, or visa-versa. Since I wasn't high risk for either, in my mind both are in play for me.

@psychometric, keep us up to date on what you find out from MD Anderson. I am corresponding with a friend that just started Proton EBRT for PCa there this week.

Best wishes!