Posted 3/12/2016 1:10 PM (GMT -5)
The DNA damage affects all the cells in your prostate. The healthy ones self-repair or die trying, while the cancerous ones, if not destroyed immediately, will die when they try to replicate - which can take several years. That's why radiation works - it kills cancer cells more effectively than healthy cells. The radiation (it doesn't matter if it's external or internal) will shrink your prostate eventually, but before that happens it will be inflamed for a while. With seeds, the inflammation lasts somewhat longer because the radiation lasts longer. You might find that a daily NSAID (like ibuprofen or naproxen) helps prevent inflammation, but check with your cardiologist, of course.
Maybe you got an infection from the fiducial placement (I did!).
If there will be erectile dysfunction, it will not be this soon - it can take up to 9 months to show up. It takes a while for the scar tissue that causes it to build up. The best you can do is work it every day and take daily Viagra to protect those tissues.
Vigorous daily exercise is very important during radiotherapy.