Proton vs. HDR Brachytherapy

Hello. I am about ready to choose my course of radiation therapy. I'm 82, in good health, Gleason score of 8-10, current PSA 0.87 down from 24. Been on hormone therapy for 8 months including Lupron (sp.) shot and daily dose of Chemo pills (Abiraterone Acetate). I am not experiencing any side effect in this regimen. To date I am favoring protron therapy; however, I just discovered "High Dose brachytherapy. HDR brachytherapy involves surgically implanting very tiny plastic catheters into the prostate gland and then giving a series of radiation treatments through these catheters. A computer-controlled machine pushes a highly radioactive seed into these catheters, one by one, carefully controlling the dose of radiation by monitoring how long each seed remains inside at a certain position. This enables delivery of a higher dose to the tumor while ensuring the surrounding tissue like the rectum receives lower doses. The catheters are then easily pulled out, leaving no radioactive materials inside the prostate gland."

"HDR brachytherapy is usually combined with a shorted course of IMRT (external radiation). HDR brachytherapy along with IMRT allows a higher dose to be delivered to the prostate as compared with IMRT alone. This is because the radiation dose is delivered internally and concentrated to the prostate. Numerous studies have shown improved prostate cancer survival with the combination of HDR brachytherapy and IMRT."
"Not my words - they are taken from a report"

I have two questions:
Does HDT therapy results match or supersede protron therapy and does HDT have a significantly lower impact on adjacent tissue/organs? Particularly the colon?

Does Mayo Clinic offer HDR brachytherapy?

I have also learned HDR brachytherapy can be completed within a two week period. I expect the number of sessions to complete the IMRT (external radiation) varies by case and is likely to require 25 or more days to complete.

I appreciate your comments and look forward to success.
Hook4fishes