It sounds like you had a biopsy and the test came back positive for cancer on both sides of the prostate. It also sounds like you had a CT scan for placement of the prostate prior to getting ready for external beam radiation. They will sometimes put fiducial markers in the prostate (they act like a global positioning system of the prostate) so that during the radiation they can tell exactly where the prostate is and if it gets out of alignment the radiation equipment stops.
There is no one right way to treat prostate cancer and doctors will have different opinions as to what to do. Often the Urologist will say surgery is the best way to go and the Radiation oncologist will say radiation is the best way to go.
You need to call the doctor office and find out your Gleason score from the pathology report. Also you have the right to get copies of all of your medical records.
Have a thorough, and I mean thorough, discussion of the side effects of any treatment you are considering with your doctor, as these can be considerable and many doctors give short shift to side effect counseling with patients prior to treatment.
Depending on your Gleeson score, you may be able to control the cancer with diet, supplements, and exercise.
Other treatments for prostate cancer include active surveillance, radiation, cryosurgery, HIFU, surgery, and androgen depravation therapy. Not all of these will be indicated for you based on your medical records/history.
Prostate cancer is usually very slow growing (depending on Gleason score) and if you do nothing with a low Gleason score cancer you are likely to be alive in 10 years.
Do not be scared, but educate yourself about the disease. It is usually reasonable to take 2-3 months to investigate your options and use that time to choose what you want to do.
Best wishes to you.
Gene