Krumlov, welcome to the forum, sorry about
Generally speaking, I think there are no hard and fast rules, but many men, upon knowing that the cancer has escaped the prostate (thus staged T3) and that they'll have to have RT anyway, would opt to not have surgery. The side effects of surgery are avoided by many (not all), but if surgery is followed by RT, it reduces the chances of avoiding such side effects.
On the other hand, some believe it's better to have the surgery before RT to "debulk" the tumor.
Unfortunately, there are few hard and fast rules when it comes to PC treatment, and it's often left to patients to make the final decisions
Others will be here shortly , more knowledgeable than I am, and may have more concrete info. Good luck
Dx Age 64 Nov 2014, 4.3
BX 3 of 12 cores positive original pathologyG6, G6, G8 (3+5)
downgraded to 3+3=6 by Dr Epstein, JH
RALP with Dr Ash Tewari Jan 6, 2015
Post surgical pathology – G7 (3+4), ECE, Margins, LN, SV all negative
PSA @ 6 weeks 2/15, .<02, 4/15 <.02 7/15 <.02, 10/15 0.00 (new lab)
My Story: tinyurl.com/oo9x4aq