The Most Common Questions Patients Ask About Radiation Treatment for Prostate Cancer – For Men who Have Already had their Prostate Removed
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What is radiation and how does it work?
Radiation therapy is a type of x-ray treatment. X-rays require very high voltages to generate them, and these rays are invisible and can pass through the body. Radiation therapy x-rays beams are much more powerful then you would find in a normal chest x-ray, and they are focused on the cancerous area. These rays damage cells in their path, especially the DNA molecules inside cells. Normal healthy cells can repair this damage, but cancer cells cannot repair the damage as well, so some of the cancer cells will die off after each radiation treatment. That is also why radiation treatment takes many days to give — each day we give a small dose of radiation that your normal tissues can tolerate and repair, but the cancer cells cannot heal themselves and will gradually die off.
What happens to the cancer cells when they die?
Billions of normal cells die every day inside your own body, and new cells are regenerated to take their place. The body has built in ways to recycle dead cells into their basic amino acids, fatty acids, and other building blocks. When a cancer cell dies it is recycled by the body just like any other dead cell. A cancer cell is only dangerous if it is alive and capable of dividing to form other cancer cells. When it’s dead it is not contagious, it has no way to turn other cells into cancer, it is not poisonous. A dead cancer cell is just a bunch of nutrients for your body to reuse.
If I don’t have a prostate, why do I have PSA?
PSA is an enzyme (a protein) that is manufactured by the prostate gland. Prostate cancer cells also make PSA. Since your prostate gland has been removed, if your PSA is rising the only source for this is from prostate cancer cells that are still in the body. These cancer cells may be anywhere in the body: in the tissues around where the prostate used to be, in the lymph glands, or in the bones. Generally, there is no way to know for sure which situation is occurring, but statistically, the most likely place for the cancer to be coming back is in the tissues where the prostate gland used to be. When we give post-prostatectomy radiation we are playing the odds that the PSA is coming from cancer cells that are located in the tissues around where the prostate used to be.
Do I need any scans?
If you have never had scans, or if it has been many months since you had them, a bone scan and a CT scan may be recommended. The bone scan looks for cancer in the bones, and the CT scan looks at the lymph glands in the pelvis and abdomen. However, if your PSA is less than 1.0, the amount of cancer is probably so small that scans will be unable to detect the cancer. For this reason, scans are often not done when patients are sent for radiation after prostatectomy.
If there’s no prostate, how do we know where to aim the radiation?
We aim at the tissues where the prostate used to be, under the bladder and in front of the rectum. This is known as the “prostate surgical bed”. The bladder and the rectum and the other surrounding tissues get pulled towards the empty area where the prostate previously was. When we radiate, we end up treating a little more bladder and rectum than we typically do with normal prostate radiation.
Will I be cured? What’s the goal of treatment? Are there other options?
Being sent for radiation after surgery can be a little bewildering. After all, the surgery was supposed to get it all and take care of the cancer. Now, you’ve been told that the surgery may not have gotten all the cancer. The goal of treatment now becomes a second attempt to cure the cancer, to make sure it never comes back in your lifetime. However, just like surgery, the radiation does not have a 100% guarantee of curing it. After prostatectomy there is about a 90% chance that the radiation will reduce the PSA, but only about a 50% chance of having long term (more than 10 years) of controlling / curing the cancer. There are not many other options available, just watchful waiting (active surveillance) or hormone therapy. You can hold off treatment and simply monitor the PSA. However, the longer you delay treatment, the harder it may be for radiation to cure the cancer. The other option is to go on hormone therapy, which will slow the cancer down but will not cure it.
How long until I start treatment?
When you consult with your radiation oncologist for the first time you will not be starting treatment that day. Typically it takes about 1 week until you start. There are a few steps to be done first. You will need to undergo a simulation / mapping procedure where we take a scan of the pelvis, then have computer planning, then a mock treatment to make sure everything lines up properly, then you’re finally ready to start treatment. In addition, if your prostate cancer is very aggressive than you may possibly need to go on hormone therapy for 2 – 3 months first before radiation even starts! Don’t worry about the delay in starting radiation because prostate cancer is very slow growing. And if you will be on hormone therapy then that will already be killing the cancer before the radiation starts.
Is there a certain dose you use? Is it individualized?
Radiation is prescribed as a daily dosage to the prostate gland given for a certain number of days = the total dosage. A typical treatment course I give after prostatectomy is 180 centiGray each day, given for 39 treatments, = 7020 centiGrays in total (180 cGy x 39 = 7020 cGy). Treatments are given once a day, 5 days a week, and therefore 39 treatments will take 8 weeks. A centiGray is a unit of energy, basically how much radiation energy you are putting into a unit of tissue. We do individualize the dose. If it has been less than 6 months since the surgery we will give a little less treatment. We don’t have any tests to tell us exactly how much dose your cancer needs, so we tend to use the highest dose that will likely cure your cancer and that can be safely given.
What is a typical treatment like?
Each day you will come in at your appointment time. You should have already drunk 16 ounces of fluid and have a comfortably full bladder. The therapists will bring you into the radiation treatment room. You will lie down on the treatment table, with your pants and underwear pulled down to your knees and a towel covering you. Your legs will be in an “immobilization device” so that you cannot wiggle around much. The therapists will then adjust the treatment table so that the tattoo marks on your skin line up with laser lights in the room. The therapists will then leave the room and the machine will do a scan of your prostate area. Your bladder, rectum, bones, and other tissues show up on this scan. The table is then finely adjusted to make the bladder and rectum line up perfectly so that the prostate surgical area will be centered in the middle of the treatment beams. Next, the treatment is run. The treatment machine will slowly rotate around the treatment table, and it may pause at different angles for the radiation beam to be delivered. The radiation beam will be on for a few minutes in total. When the beam is on, you may here clicking noises from the aperture shaping the radiation beam and adjusting its intensity. You cannot feel or see the radiation beam. Once the radiation has fished, the therapists will come in the room, lower the treatment table, and you are on your way!
Are there any restrictions while on treatment?
There are almost no restrictions. You can drive yourself to and from treatment, and do your normal activities and your work. You will not feel sick. You can eat before treatment. You are not radioactive or contagious. You can have normal sexual relations. You can eat your usual diet, but this may be modified if you develop bowel irregularity. You can exercise and if fact should exercise regularly to help prevent fatigue. Some activities may irritate the tissues while you are undergoing radiation such as riding a bicycle, motorcycle, lawn tractor, or a horse — approach these activities cautiously as they may cause some discomfort. Almost all medicines can be continued while on radiation, some exceptions would be certain chemotherapy and immune suppressant drugs. Cold, allergy, and cough medicines can make it harder to urinate.
What happens if I miss a treatment?
Sometimes you end up missing a day or two — maybe it’s a holiday, the weather is bad, you’re feeling sick, you had a long weekend planned, etc. Sometimes the radiation machine is being serviced by engineers and there are no treatments that day. What we do in these cases is that we just tack that missed treatment onto the end. You’ll still end up with the same number of treatments, but you will finish 1 day later. Missing a few days here or there will not affect the success of the treatment. Missing a few weeks may possibly lower the success. If you have to miss a lot of treatments we may do some twice-daily treatments to catch up some.
How do you know you’re hitting the right spot?
Since the radiation beams cannot be seen or felt, and the prostate gland is gone, many people wonder how we know we are aiming those invisible beams properly. It all starts with the mapping simulation CT scan. Your body is positioned on the scanner the exact same way it will be positioned for each of your radiation treatments, and a coordinate system kind of like GPS is created. Just like a guided missile can be aimed for a certain coordinate on earth (like the Kremlin at 55.7517° N, 37.6178° E ), radiation can be targeted at a certain coordinate in your body, relative to the the little tattoo marks that were placed on your skin. Secondly, the treatment machine will do its own CT scan immediate before each radiation session. The therapist will look at the bladder and rectum on the daily CT scan, and do some fine-tuning to ensure the prostate surgical area will be in the center of the radiation.
How do you know the right amount of radiation is being released?
Each person has his own treatment plan, which is like a computer program that directs the treatment machine. The treatment plan controls how many radiation beams enter the body, what shape they are, how strong they are, how long they’re on for, etc. Before you have any treatments, the physicist will run your treatment plan on a plastic dummy that has radiation sensors built inside. He verifies that the dummy receives gets the identical dose that was prescribed for you. Secondly, the radiation machine has built in monitors to ensure that the radiation beam is being generated at the correct strength.
Will the treatment make me sick?
No, it will not make you sick. There is no nausea and no hair loss. You will be able to do all of your usual activities and work. Some men may get a little fatigued.
What side effects can I expect?
Radiation therapy will cause some short term inflammation in the bladder, and rectum. Urinary symptoms can include more frequent urination during the day and night, having to rush to the bathroom (urgency), a slower urine stream, some burning, and possibly a little leakage. We may prescribe medications like oxybutynin to reduce bladder irritability. Some good news is that urinary side effects tend to be less in men who already have their prostate removed. Rectal side effects can include mild diarrhea or constipation, hemorrhoid irritation, mucous in the stools, and bowel urgency. You may get a few small suntanned patches on your skin in your hips and pelvic area. These short term side effects will begin a few weeks after you begin radiation, and they usually go away within 1 – 2 months after completing radiation. Sometimes some scarring will occur when the inflammation heals which can cause long term side effect of additional weakening of the erections, and a small chance of urinary leakage or rectal bleeding.
Do you monitor the cancer during treatment?
No. The treatment machine takes daily CT scans to make sure that everything lines up properly, but the scans do not show the cancer in the body. In addition, we don’t check the PSA during treatment because it may rise due to inflammation. Your radiation oncologist does monitor your side effects and he also monitors to make sure that the treatment is lining up properly each day. He visits with you once a week to make sure you are tolerating treatment OK.
When do I get my first test to see if the cancer is gone?
The main way we monitor the cancer after treatment is completed is with the PSA blood test. We usually wait 3 months after treatment before checking the PSA, to give the inflammation a chance to settle down. By the 3 month mark the PSA is hopefully dropping down towards 0.00. There are no routine scans done after treatment unless the PSA starts to climb.
How do you know the cancer has been cured?
Unfortunately there is no test you can do to prove the cancer is cured. After treatment the PSA blood test should drop down to a low value, and stay there. The more months and years that have passed since treatment is completed and the PSA remains low, the higher the chance that it is in fact cured. If at 3 – 5 years after treatment your PSA is less than 0.10 then you have a very good chance of being cured.
What happens if the cancer comes back?
If the PSA goes up several times in a row after treatment, this could be the first sign that the prostate cancer is coming back. At that point scans may be done. If it looks like the cancer has spread to the bones or lymph nodes then the treatment will be hormone therapy injections to slow it down. Unfortunately there is no further treatment that can be done to attempt to cure the cancer if both surgery and radiation have failed — it is only a matter of trying to control it.
Are there any other questions I should have asked?
Always make sure you know your treatment options, the side effects, and the goal of treatment. However what you really want to ask your doctor but may be afraid to ask is, “Will I be cured? If i’m not cured will I die from my cancer and when? Will I be able to keep having a normal sex life? Will I avoid urine leakage? Is this the best treatment for me?” These answers are tough because they boil down to statistical odds rather than a Yes or No answer, and what you really want is certainty.