Radiation Treatment for Prostate Cancer
The initial consultation allows the radiation oncologist to get to know you and perform a physical exam. In addition, you may ask any questions that have not already been answered. Your written consent will be required to begin the treatment-planning process. A simulation (treatment planning session) will be scheduled once you decide if radiation is the right option for you.
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Treatment planning is a three-step process that usually takes about two weeks to complete.
1. Prostate Simulation
The simulation process provides your treatment team with the data to allow the construction of a highly individualized plan to treat your prostate cancer while minimizing the dose to normal adjacent structures. The process relies on a spiral computed tomography (CT) scanner to obtain a detailed digital data set of as many as 130 cross sections of the relevant pelvic anatomy. This dataset is then used by your physicians to create a three-dimensional model of the area to be treated.
The simulation is done for treatment-planning purposes only, and usually lasts for 45 minutes to an hour. It is extremely important to lie as still as possible on the table, because movement can alter measurements and increase simulation time.
A urethrogram is performed to help localize the prostate. Contrast solution is inserted into the penis and a temporary restriction device is placed at the base of the penis to prevent the liquid from escaping during the CT. Patients may feel some pressure, but there usually is no associated pain. A small-caliber tube is also placed in the rectum to more clearly define it. Very rarely, patients will have some blood in their urine for a few days following the urethrogram. This will go away on its own.
The CT scan is then performed. Finally, three or four small black dots will be tattooed, one on each hip area and one or two in the pubic region. These permanent tattoos serve as landmarks for your upcoming radiation therapy. Some photographs will be taken for documentation purposes.
You should be able to drive to and from the simulation process. For the next two days, drink four to six glasses of water a day.
2. New-Patient Confirmation Films
You will be scheduled for a "new patient" time on the linear accelerator. It takes approximately 30 minutes to take some X-rays confirming your treatment plan. Your actual radiation treatments will be started either the following day or the beginning of the next week.
* Additional Films During Treatment
Additional X-ray films are often taken during treatment as part of planning procedures and for quality assurance.
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Radiation treatment for prostate cancer typically takes seven to eight weeks depending on the stage of disease. (Irradiation given for consolidation following a brachytherapy implant takes four to five weeks depending on the type of implant and original stage of disease.) Treatment is given Monday through Friday, except on holidays. The treatment takes about 15 minutes a day, and the radiation beam produced by the linear accelerator is only on for a few minutes. You will need to stay still while the radiation is being administered. We request that you be treated with a full bladder, which will move some of the bladder out of the treatment field, potentially decreasing urinary side effects.
In addition, avoid herbal supplements and high-dose anti-oxidants such as vitamin C, E, beta-carotene and selenium during radiation since these could theoretically interfere with the radiation's desired effect. However, a multi-vitamin (with no more than 100% of the RDA) and vitamins found in foods are okay. Spicy foods should also be avoided during radiation since these may cause rectal irritation.
Each Tuesday or Wednesday, you will be asked to see one of our doctors after your treatment. This is an opportunity for the radiation oncologist to see how you are doing and for you to express any concerns or questions you may have. Friends, family or caregivers are welcome on this day if that is your preference. Although Tuesdays or Wednesdays are the main days to see the doctor, we are happy to see you any day of the week.
In general, side effects do not become apparent until about the second or third week into treatment. Most people can continue their daily activities, such as going to work and exercising, without any problems. The side effects of prostate radiation can be explained by the anatomy of the prostate in relation to other structures in close proximity. The prostate lies directly below the bladder and surrounds the urethra, which allows urine to pass from the bladder. The rectum is behind the prostate and the nerves that control erections surround the prostate. Below are some of the possible side effects of radiation.
Loose stools may occur in less than five percent of patients and almost always resolve after completing radiation. In general, we do not recommend significant change in your diet unless you notice a change in your bowel habits, although we do suggest you limit spicy foods. If the loose stools or diarrhea become a problem for you, we recommend decreasing dairy products and avoiding high-fiber foods such as fruits, vegetables and grains. If dehydration is an issue, increase fluid intake. For mild diarrhea that is bothering you and not responding to dietary changes, you may take over-the-counter Imodium as needed. We also can prescribe a stronger anti-diarrhea medicine if needed.
Peri-anal skin irritation occurs in about 30 percent of patients but is mild and self-limiting. A sample of a petroleum-based product called Aquaphor is usually supplied. Aquaphor may be applied after treatment and at night; however, do not apply up to three to four hours prior to treatment. It is prudent not to rub the area. We recommend that you avoid chlorinated swimming pools and hot tubs. The skin irritation usually heals completely after the treatment course is finished.
Proctitis is an inflammation of the rectum that causes some blood in the stools in approximately five to 10 percent of patients during and/or after treatment. It is usually mild, often related to pre-existing hemorrhoids and self-limiting. If this problem persists after radiation therapy, a consultation with a specialist may be scheduled to investigate the cause. About one to two percent of patients may require intervention if the symptoms persist.
Incontinence of urine and/or stool that is significant rarely occurs during or after radiation therapy.
Urinary changes that may occur acutely during radiation include increased urgency and frequency of urination, burning and trouble starting the stream. Rarely, there may be blood in the urine that usually becomes apparent after treatment. If it persists, an evaluation is indicated to be sure there is no other problem. If it does occur, it is usually self-limiting.
Erectile dysfunction can either become apparent right away from hormonal treatment or appear several months later. The risk of erectile dysfunction is variable -- it depends on your age, general medical condition, medications and your pre-treatment level of sexual functioning. In general, the risk of erectile dysfunction is approximately 20 to 35 percent. Options, including the drug Viagra, are available from PAMF's Department of Urology and might help restore erectile function.
Semen volume will decrease or become absent because the prostate provides some of the fluid that comprises the ejaculate. If you are considering having children in the future, sperm banking is recommended prior to undergoing treatment.
Fatigue may occur during the latter part of radiation, but it is usually not a significant problem for most patients. Usually, the tiredness will go away several weeks after treatment.
Uncommon complications of urinary blockage requiring a catheter or urethral stricture (urinary scar tissue) needing removal occur rarely.
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After your radiation treatment, a follow-up appointment may be scheduled for you to be seen in four to six weeks. You may have a PSA test every year. If possible, have your PSA test done one to two weeks prior to your follow-up appointments so the results are available ahead of time.
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