...The optimal dose of radiation without the extra-glandular side effects is Interstitial Radiotherapy (a/k/a permanent seeds/ 'Low' Dose Radiotherapy,/LDR brachytherapy, Low dose is a misnomer. It is low dose over weeks or months which makes it higher than the others. Time is the relevant dose factor. All external beam radiotherapy [EBRT] must be suboptimal because the various beams converge inside after passing through healthy tissue at various angles. Fiducials, spacers are attempts to minimize the unavoidable risk of side effects by the converging sub-optimal rays. When I asked the surgeon about 'Seeds' he laughed and said "Find someone to do it." I did. All of the factors in your case can be discussed with clinicians that have done 6-10 thousand procedures. Go to the Prostate Cancer Research Institute (PCRI.org) and look up videos on brachytherapy, etc. The outpatient procedure is about 30 minutes.