A prostate problem is not necessarily prostate cancer. Laser treatment is often used in Britain for a TURP which in turn is a procedure which can be used to shrink the prostate down to the maximum size greater than which brachytherapy becomes problematic. A TURP can also be scheduled if the prostate were so large as to induce retention and, in Britain again, the necessity for self catheterization.
Brachytherapy is on offer at Addenbrookes Hospital, Cambridge. They perform a limited number each year and therein lies one of the main problems with brachytherapy in Britain, finding the one urologist and the one nuclear radiologist who have done enough of the procedures so as to be able to eliminate most of the unpleasant after effects.
As to the original question and speaking off the cuff, I would imagine that, having notified the CAA medical section of your problems, they will send you a protocol schedule for completion by your specialist for submission to your AME when you go to see him to have your temporary medical suspension lifted.
I would imagine that six weeks recovery would be a sensible ball park figure.