Dave, I would like to add my welcome to our little club that none of would have chosen. I know it can be overwhelming at first, and the responses that are telling you to slow down, to consider ALL your options, etc.
I'll agree with the rest: With a single G6 core, at age 54, you certainly don't need immediate treatment, and you may never need aggressive treatment. Here's how it worked for me: I was just past my 56th birthday when I had my third annual doubling of PSA, and I was sent to urology. I had the biopsy, and came back positive--with 3 G6 cores. The first thing the urologist told me was, "You have at least 6 months to decide what you're going to do."
I chose surgery, and have had a great outcome. With a single G6, active surveillance is a great option--it simple means that they keep a close eye on things, with regular PSA and DRE tests, a second biopsy within a year, and IF something changes, then you go to aggressive treatment. Over the long haul, it makes absolutely NO difference to your prognosis.
If you do decide to treat, radiation might be a great choice--but the old 40+ treatments is not the only way. You can go brachytherapy--where radioactive seeds are implanted in the prostate to cook it over time. Or there is SBRT--where the insert gold pellets in there, and use them to focus radiation beams, and it's over in 5 treatments over a 2 week period. You owe it to yourself to find experts who do these different things and talk to all of them. You have the luxury of time. Use it well.
Age at Diagnosis: 56
RALP on 2/17/15, BJC St. Louis, Dr. Figenshau
58.5g, G3+4, 20%, 4 quadrants involved
PSA 3/10/15: 0.10
My Story: www.healingwell.com/community/default.aspx?f=35&m=3300024