@ecurb
My post of information always come from urologists, R/O, etc. You can look up the treatment plans about radiation and what they actually do. Both Mayo Jacksonville and UFHPTI are my source of information.

UFHPTI gives out a free handbook including two books. Some new specific type radiation is done to kill specific tumors or areas of cancer cells but most are to treat entire prostate so don't miss and cancer cells not caught on MRIs or biopsies.

The cells inside the prostate will be damaged by radiation it does not kill the prostate gland. The normal cells can heal and reproduce. Prostate cancer cells are unique and the radiation damages the cells and they do not reproduce or heal and thus eventually die.

It is just like the hormone treatments. Hormone treatments do not kill the cancer cells. It starves them from testostorone which feeds the cancer. So stopping the feeding keeps the cancer from growing and thus what ever treatment you get is helped. It does not kill the cancer so if you miss some cancer cells with surgery or radiation they will begin growing after treatment ends.