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External-Beam Radiation for Prostate Cancer: Practical Tips
University of Michigan radiation oncologist and PCF-funded investigator Daniel Spratt, M.D. provides advice to help you be at your best for daily treatments.

If you are about to undergo external-beam radiation for prostate cancer, you may find that the treatments themselves are easy.  Preparing for the daily treatments, however, may take some getting used to – but you can do it!

Here with some tips is University of Michigan radiation oncologist and Prostate Cancer Foundation (PCF)-funded investigator, Daniel Spratt, M.D.  The most important thing you can do, Spratt advises, is to familiarize yourself with the anatomy of the pelvis; your doctor may have literature with an illustration that will help.  If not, here’s one  (see Figure 3) that will give you a better understanding of where the prostate is, and the important anatomy nearby.

Seeing the big picture – literally – will help make it clear why your doctor “is asking you to come to your treatments with a comfortably full bladder and an empty rectum,” Spratt says.  “Having a full bladder is going to move the intestines upward and away from the radiation, and having a rectum about the same size every time – the way we planned it before your treatment – helps us be very precise, to make sure we’re giving all that dose to the prostate and not hitting the rectum, or that we’re avoiding the rectum but also missing some of the prostate.  It allows us to use very tight margins,” treating every bit of the cancer but not harming the normal tissue.  “Every program has a slightly different protocol, but the main thing is to keep things generally about the same every time.”

So:  how do you know your bladder is full enough, but not too full?  You measure what you drink.  “We give patients a water bottle during the planning simulation scan (before treatment starts),” says Spratt.  “How their anatomy looks that day is what we’re trying to replicate each day of treatment.”  When Spratt’s patients come in for their simulation, “We say, ‘Go urinate.’  Then we give them about 20 ounces of water in the water bottle.  Some patients can drink more, some can’t.  We usually wait about 45 minutes to an hour to let that water get to their bladder, and we see how it looks.”  Then they draw a line on the water bottle, so patients know exactly how much water to put in.

What about the rectum?  Ideally, Spratt says, “we recommend that most patients try to have a bowel movement four to six hours before a treatment.  We don’t want a lot of stool and gas, because the rectum can grow to over five times its normal diameter.”  However, he adds, don’t despair:  “Patients should also know that they shouldn’t be extremely concerned.  There are things the doctor can do to help.”  Changing the diet can reduce this problem, as well.  “This is one of the few times I tell patients, ‘Maybe during treatment, don’t eat excessive vegetables and fiber, because that can make you gassy.  Or, if you’re constipated, maybe you need to have more fiber.”  But this can be figured out!  It will be okay.

“Usually, just understanding the process and what we’re trying to do helps patients do so much better,” says Spratt.  “If they’ve got an empty bladder, we show them the scan on the machine:  ‘This is where your intestines are now,’” compared to where they need to be.

Keep up the good work on the weekends, even though you aren’t getting treatment.  Don’t go hog-wild with a radically different diet on the weekend; some remnants might still be in there on Monday morning.  Also:  “Guys tend not to drink a lot of water during the day,” notes Spratt, “and especially on the weekends.  What can happen is that your body gets dehydrated – and even though you drink water before your treatments, it doesn’t go to your bladder.”  Instead, it gets shortstopped by parched tissue throughout your body that needs rehydrating.  “For the treatment, at least, try to drink four to six glasses of water a day just to stay hydrated – so when you drink your water before your treatment, it’s actually going to go to your bladder.  Some men have to drink 48 ounces just to get it to their bladder, because they never drink water!”  If you keep the fluids going throughout the day, “you don’t have to drink that much before the treatment to get the bladder comfortably full.”

What if it’s hard for you to hold it?  Again, don’t despair!  You’re certainly not alone, particularly if you had a prostatectomy.  Also, some men just have incontinence issues, “and sometimes holding a full bladder is challenging for them,” says Spratt.  “Some men need to have not quite as full of a bladder.”  One man’s “comfortably full” is another man’s white-knuckler.  “For some men, if it’s too full, they start to leak.  Some men leak quite a bit, even with minimal pressure on the bladder.”  Talk to your doctor:  you may find that a penile clamp helps keep the bladder full for those critical few minutes of radiation treatment a day.  “Some men use it anyway for incontinence issues, but some men use it just for the treatment to prevent any leakage, and when they’re done, they go urinate.”

Janet Worthington
Janet Farrar Worthington is an award-winning science writer and has written and edited numerous health publications and contributed to several other medical books. In addition to writing on medicine, Janet also writes about her family, her former life on a farm in Virginia, her desire to own more chickens, and whichever dog is eyeing the dinner dish.