A man in my support group has a pacemaker and was treated with SBRT for high risk PC, similar to Lupron Jim. The only thing that was different because of his pacemaker was that he could not have an MRI for planning, but had a CT instead. Patients in that protocol usually have both and the images are fused. He also needed a note from his cardiologist saying it would be OK.
Have you looked into combo treatment with ADT+IMRT+brachy boost? The outcomes have proven
to be much better than without the brachy boost for high risk cases. You can read about
a very recent comparative study on this:EBRT + LDRBT boost provides superior cancer control compared to EBRT alone
As you can see. it is better than IMRT alone when combined with either kind of brachy (LDR or HDR). It also reduces the treatment time to less than 5 weeks.