Patients often ask, "What are the side effects of treatment for each of the individual treatment
options?"
Well, with surgery has two major side effects beyond the risks of surgery—infection, bleeding,
etc. The two major side effects of the procedure are impotence and incontinence. Now for incontinence,
that's leakage of urine, any sort of leakage, any sort of leakage is about a third of patients.
And what I mean by that is people leaking when they lift something heavy or playing
tennis or when they laugh. So when you ask large groups of patients in health services
research studies, "Do you leak?" about a third of them will say yes to that question. 2%
or maybe a little bit less of patients will have severe leakage requiring additional surgical
intervention by the urologist or use of diaper or clamps to prevent the leakage. Some of
that is just the nature of the surgery. The surgery is done in such a way where the prostate
is taken out and then when it's sewn back together, when the edge of the urethra are
sewn back together, it's near where the sphincter, the muscle that controls continence that stops
the leakage, it's just right near there, so mechanically sometimes some patients will
just leak which it just kind of comes part and parcel with the surgery. Now, impotence
also goes along with radical prostatectomy and the number that tends to be reported is
about a 50% rate of impotence. Now the impotence from surgery is a nerve based impotence, in
other words, there are nerves in the periphery of the prostate which are associated with
potency. Now, these nerves are not big nerves that the surgeon can see. They're small bundles
of nerves that are anatomically in an area where the surgeon, where the urologist, knows
where they are and they attempt to spare those nerves in the so-called nerve-sparing prostatectomy,
but they're not always able to do that. One reason might be that the tumor is nearby.
Another reason is that these areas are hard to locate. So about 50% of patients may end
up being impotent. So this nerve based impotence is cutting the telephone wires, cutting the
communication to allow for erections and potency.
Now, with radiation, side effects are a little different. Incontinence is not a primary complication
or side effect of standard radiation treatments—certainly not without a surgical intervention precipitating
incontinence. However, rectal problems and rectal damage are. Going back 15 years, rectal
damage were 15 to 20% of patients. With the advent of IMRT and that ability to shape dose
and bring dose off the rectum and bring dose off the bladder the risk of asymptomatic rectal
bleeding (what we call a grade 2 complication) runs between 2 and 4% depending on the study
you read and symptomatic rectal bleeding requiring the GI doctor to go in and zap a little bleeding
blood vessel in the rectum—that risk is about a half of a percent. So these are fairly
low risk. the bladder problems that used to be associated with external beam radiation
15 years ago, 15-20% risk in those days, have fallen to less than 1% with these new IMRT
techniques and some of the other techniques that I've described to you.
Now, we're seeing the same risk of complications with stereotactic body radiation, the SBRT.
As I mentioned before in the permanent seed implant the risk profile is a little different.
They have a unique risk of causing urethritis, irritation of the urethra or burning on urination,
and they have an asymptomatic rectal bleed rate of about 5 or 6%. More than the IMRT.
The high dose rate interstitial implant has a risk profile of complication very similar
to the IMRT and the SBRT with very low rectal and bladder complications.
The mechanism by which radiation causes impotence is a vascular based impotence. It turns out
that the nerves are basically radiation resistant, but the vasculature is not and what radiation
does is it accelerates the aging process. If, for example, you look at a group of 70-year-olds
who are potent who receive radiation and then look at them seven years after the radiation
about half of them are impotent. It's the same 50% that is often reported with the radical
prostatectomy except in that situation what you got is 70-year-olds becoming 77-year-olds,
and over that period of time some of those folks will become impotent and in fact, that's
exactly what's happening. The radiation is accelerating the aging process. That being
said, nowadays, there are vascular based treatments for vascular based impotence, the kind of
impotence that radiation causes. Drugs like Levitra, Cialis, and Viagra. In randomized
trials, the reversal of radiation-induced impotence is about 80% with these medications.
Other medical conditions can affect complications such at as potency. Patients with diabetes
or cardiovascular disease such as a history of heart attacks or strokes or peripheral
vascular disease have a much higher incidence of impotence in general, and certainly a higher
incidence of radiation impotence as well. Smoking is also a predisposing factor towards
impotence in general, certainly vascular disease, and smokers have a much higher likelihood
of becoming impotent after radiation therapy.