In comparison, 37% of men who had received external radiotherapy as their primary therapy reported the ability to attain functional erections suitable for intercourse, along with 43% of men who had received brachytherapy as primary treatment. Pretreatment sexual health-related quality of life score, age, serum prostate-specific antigen (PSA) level, race or ethnicity, body mass index, and intended treatment details were associated with functional erections 2 years after treatment. 
Choosing the treatment that is best for you comes down to preference and efficacy. Montague cites a study that surveyed three groups of men, all of whom were successfully using an ED treatment. One group was on oral medications, one was using injections and a third had surgically implanted pumps. The most satisfied users were those with the implanted prostheses.
This penile tumescence monitor is placed at the base and near the corona of the penis. It is connected to a monitor that records a continuous graph depicting the force and duration of erections that occur during sleep. The monitor is strapped to the leg. The nocturnal penile tumescence test is conducted on several nights to obtain an accurate indication of erections that normally occur during the alpha phase of sleep.
There are two kinds of surgery for ED: one involves implantation of a penile prosthesis; the other attempts vascular reconstruction. Expert opinion about surgical implants has changed during recent years; today, surgery is no longer so widely recommended. There are many less-invasive and less-expensive options, and surgery should be considered only as a last resort.
A vacuum erection device is a plastic tube that slips over the penis, making a seal with the skin of the body. A pump at the other end of the tube makes a low-pressure vacuum around the erectile tissue, which results in an erection. An elastic ring is then slipped onto the base of the penis. This holds the blood in the penis (and keeps it hard) for up to 30 minutes. With proper training, 75 out of 100 men can get a working erection using a vacuum erection device.