You could research and/or ask about brachytherapy. Advocates of brachytherapy claim that external beam plus brachytherapy boost, and depending on your risk classification, more or less ADT, offers the longest freedom from recurrent disease, because the total radiation dose to the prostate is higher than any other therapy can safely produce. It may be that once the SBRT is planned and performed its too late for brachy but....

Otherwise, it seems very wise to keep up the "rigorous strength training" you are already doing.

Apologies if you are already quite familiar with this guy: the most prominent advocate of exercise as a first line treatment, or as a "what to do next" treatment is Dr. Rob Newton.

Newton published a short article with a good description of why exercise can be viewed as medicine, and what exercises to perform at different stages of a prostate cancer journey in 2022 "Prostate cancer treatment with exercise medicine" https://onlinelibrary.wiley.com/doi/epdf/10.1002/tre.884

One thing that was new to me as I read this article was this statement he made:

"As stated above, each training session causes a surge of exercise medicine, so it is preferable to spread the dosage across the week and even throughout the day. So rather than do a large volume of exercise on two or three days per week, it is preferable to perform shorter bouts over five, six or even seven days."

This is a modification to the general recommendation for exercise he cites i.e. "to accumulate 75 minutes of vigorous to 150 minutes of moderate aerobic exercise each week and two or more resistance training sessions".

I was doing 30 minutes of vigorous cardio Monday, Wednesday, and Friday, and 1 hr of resistance training Tuesday, Thursday, and Saturday, with Sundays off. I'll try this idea of spreading out the resistance training to 30 minutes every day. He suggests alternating muscle groups that are exercised, so that the same group of muscles is only subjected to resistance training every alternate day.

I wish I could see an exercise oncologist of Newton's caliber as part of my treatment to get what he is calling these days a "precision exercise" prescription.

I feel like what I'm doing with my exercise program is I can see that the field of exercise oncology has matured to the point that all oncologists are waking up to the idea that exercise is a "must have" as opposed to the idea that has prevailed i.e. "good to have", but I've been left to just guess as to what to do. Its as if I could see that advocates of ADT were starting to persuade the surgeons and radiation oncologists that ADT was a "must have" in many situations, but I was left to figure out what drug, what dosage, and what length of time I should take it for.

Newton presents much more detail in his 2025 book My Exercise Medicine for Cancer.