Radiation Therapy to the Pelvis

This information will help you prepare for radiation therapy to the pelvis, including what to expect before, during, and after your treatment.

You will be getting a type of radiation therapy called external beam radiation. A beam of radiation will be directed to the tumor site from a treatment machine. The beam passes through your body and destroys cancer cells in its path.

Before you start your treatment, you will have treatment planning appointments. These include a simulation and a set-up procedure.


Before you begin treatment, you will have a treatment planning procedure called a simulation. This is done to make sure that:

  • Your treatment site is mapped out.
  • You get the right dose of radiation.
  • The dose to nearby tissue is as small as possible.

During your simulation, you will have x-rays and your skin will be marked. These marks identify the area that will be treated.

Your simulation will take 2 to 4 hours.

Preparing for your simulation

If you think you will be uncomfortable while lying still for a long time, bring acetaminophen (Tylenol®) or your usual pain medication to your simulation. Take it 1 hour before your procedure. If you think you may get anxious during your procedure, speak with your doctor about whether medication may be helpful.

The day of your simulation

  • You can eat and drink before your simulation. However, for 4 hours before your simulation, do not eat a heavy meal.
  • You can take your usual medications on the day of your simulation.
  • Wear comfortable clothes.

During your simulation

When you arrive for your simulation, your radiation therapist will greet you. He or she will take a photograph of your face. This picture will be used to identify you throughout your treatment.

Your therapist will then explain the procedure to you. If you have not already signed a consent form, your doctor will review it with you and ask for your signature. Your therapists will not begin the simulation without your permission.

You will get undressed from the waist down and change into a gown. You can keep your shoes on.

Your therapist will walk you to the machine and help you lie on the table. Although the table will have a sheet on it, it is hard and has no cushion. If you haven’t taken pain medication and think you may need it, tell your therapists before your simulation begins. Also, the room is usually cool. If you feel uncomfortable at any time, let your therapists know.

You may be given a liquid substance called contrast before your procedure. Contrast helps us see your small intestine on the scan that will be taken and can be used to locate the bladder, rectum, and vagina (if you are a female). Contrast can be given in one or more of the following ways:

  • By drinking it (about 1 cup).
  • Intravenously (through a vein), if you are not allergic.
  • By inserting a soft rubber catheter into the rectum or the bladder. About 1 cup of contrast is inserted into this catheter. This can be a little messy, but there will be a cloth underneath you that will absorb the liquid.
  • If you are a female, a small tampon can be soaked in contrast and inserted into your vagina.

The rectal catheter can also be used to deliver air. Air may be pumped in or removed through the catheter to help us see your rectum on the scan. A thin wire may also be placed near your anus. These will be removed at the end of your simulation and will not be used again until your treatment begins. This will take about 30 minutes.

Throughout your simulation, you will feel the table move to different positions. The lights in the room will turn on and off and you will see red laser lights on each wall. Your therapists use these laser lights as a guide when they position you on the table. Do not look directly into the red beam because it may hurt your eyes.

Although your therapists will walk in and out of the room during your simulation, there will always be someone who can see and hear you. You will hear your therapists speaking to each other as they work. They will explain what they are doing, but please do not speak once they begin because it may change your position. However, if you are uncomfortable or need assistance, tell your therapists. To help pass the time, your therapists can play a CD for you. You can bring one of your own from home, if you wish.

Positioning and mold

You will be lying on your stomach or back during your simulation and each treatment. To help you stay in the correct position, a mold may be made of your lower body. Your therapists will make this for you.

To make the mold, your therapist will place a warm, wet sheet of plastic over you while you are lying on the simulation table. He or she will shape it to fit around your body. As the mold cools, it will harden. You will feel some pressure as your therapist fits the mold to your body.

During your simulation and every day of your treatment, this mold will be placed over you. It will be attached to the table on which you are lying. This helps ensure that you are in the correct position during each treatment. This part of your procedure takes about 30 minutes.

X-ray images

While you are lying on the table, a computed tomography (CT) scan will be taken of the area to be treated. These scans are used only to plan your treatment. They are not used for diagnosis or to find tumors.

During the scan, you will hear the machines as they turn on and off. Even if the noise seems loud, your therapists will be able to hear you if you need to speak with them. It will take 45 minutes to have the scans.

Skin markings (tattoos)

Your therapists will draw on your skin with a felt marker. Then, they will make permanent skin markings, called tattoos, with a sterile needle and a drop of ink. The sensation of getting a tattoo feels like a pinprick. The tattoo marks are no bigger than the head of a pin.

You will receive 5 to 7 tattoos across your lower body. You can wash the felt markings off after your simulation. The tattoos are permanent and will not wash off. If you’re concerned about receiving tattoos as part of your radiation treatment, talk with your doctor.

After the tattoos are made, the therapists will take several photographs of you in your simulation position. The photographs and tattoo marks will be used to position you correctly on the table each day of your treatment.

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After Your Simulation

If you drank contrast during your procedure, take 3 tablespoons of Milk of Magnesia® when you return home. This will help get the contrast out of your body.

Treatment planning

At the end of your simulation, we will make an appointment for your set-up procedure. This is the final appointment before your treatment begins. You will also be assigned to a machine for your daily treatment.

During the time between your simulation and your set-up procedure, your radiation oncologist will work with a team to plan your treatment. They will use your simulation x-rays to plan the angles and shapes of your radiation beams. They will also determine the dose of radiation that you will receive. These details are carefully planned and checked. This process takes 5 to 7 business days.

Treatment scheduling

At the end of your simulation, your therapist will ask you what time  of day you would like to have your treatments. We will try to give you the time you like. However, we need a 2-hour window because the time you prefer may not be open. We will move you to that time slot once it becomes open. Please know that we will do our best to give you the appointment time you want as soon as we can. The appointment for the following week is usually given on Friday. The hours of operation vary at each MSK facility. Check with your nurse about the hours of operation at the facility at which you are being treated.

Radiation treatment is given daily, Monday through Friday, for about _____ weeks. If additional time is needed due to unforeseen circumstances, your radiation oncologist will tell you. Make sure you come to every appointment because treatment may not be as effective if you skip or miss appointments. If you need to change your schedule for any reason, please speak with your therapists.

Some patients get chemotherapy and radiation treatment on the same day. It can be given before or after your radiation therapy. The timing does not matter.

Set-up procedure

Before your first treatment, you will be scheduled for a set-up procedure. This procedure usually takes about 90 minutes. If pain medication was helpful during your simulation, you may want to take it before this procedure.

When you come for your procedure, you will be shown to the dressing room and will change into a gown. Your therapists will bring you to the room where you will receive your treatment each day. They will position you on the table. You will lie exactly as you did the day of your simulation. Beam films (x-rays of each of the radiation beams) will be taken to make sure that your position and the area being treated are correct. The beam films will be repeated throughout your treatment. They are not used to see how your tumor responds to treatment.

You will most likely start your treatment the day after your set-up procedure.

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During Your Treatment

After you check in at the reception desk, have a seat in the waiting room. When they are almost ready for you, your therapists will tell you to change into a gown. They will bring you into the treatment room and help you lie into your mold on the table. Once you are positioned correctly, they will leave the room, close the door, and begin your treatment.

You will not see or feel the radiation, but you may hear the machine as it moves around you and is turned on and off. You will be in the treatment room for 10 to 30 minutes, depending on your treatment plan. Most of this time will be spent putting you into the correct position. The actual treatment only takes a few minutes.

Although you are alone during your treatment, your therapists can see you on a monitor and hear you through an intercom at all times.

Breathe normally during your treatment, but do not move. If you are very uncomfortable and need help, speak to your therapists. They can turn off the machine and come in to see you at any time, if necessary.

Weekly visits during your treatment

Your radiation oncologist and radiation nurse will see you each week to evaluate your response to treatment. This visit will be before or after your treatments each ________________. You should plan on being in the department about 1 extra hour on those days.

During these visits, you should ask questions and discuss any concerns you have. If you need to speak with your radiation oncologist or radiation nurse any time in between these weekly visits, ask your therapists to contact them when you come in for treatment.

Vitamins and dietary supplements

Many patients ask about taking vitamins during treatment. You can take a daily multivitamin, if you wish. It should not have more than the recommended daily amounts of any vitamin. Do not take any other vitamins or supplements without talking with your doctor. This includes both nutritional and herbal supplements.

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Side Effects

Some patients develop side effects from radiation therapy. The type and how severe they are depend on many factors. These include the dose of radiation, the number of treatments, and your overall health.

Side effects may be worse if you are also getting chemotherapy. Below are the most common side effects of radiation therapy to the pelvis. You may have all, some, or none of these.

Diarrhea and rectal discomfort

Many people develop diarrhea (increased watery bowel movements) within the first few weeks after treatment begins. It is also common to have cramping, pressure, and discomfort in your rectal area. You may also strain to have a bowel movement with no results.

Here are some ways to help you manage these issues. Start following these guidelines if and when you begin to have symptoms. Continue them until your bowel movements return to your usual pattern. This may take 2 to four 4 weeks after your treatment is completed.

  • Follow a diet that is low in fiber, fat, and lactose (a sugar found in milk). Your nurse will give you a resource that describes this diet in detail. Continue the diet until your bowel movements return to your usual pattern. You can then slowly reintroduce foods from your usual diet.
  • Drink more liquids to replace some of the water and salts you lose from having diarrhea. Try to drink 2 to 3 quarts of liquids throughout the day. Choose liquids such as Gatorade®, juices and nectars, non-fat soup broth, and Pedialyte®. Limit liquids with caffeine (e.g., coffee, tea, colas), as they can dehydrate you.
  • Eat bananas and potatoes without the skin. They can help replace important nutrients you may lose from having diarrhea.
  • Avoid any food or liquid that makes your symptoms worse.
  • Take Imodium®. Please follow the directions below and not what is printed on the package.
    • Take 4 mg by mouth followed by 2 mg after each loose stool. You can take up to 16 mg in a 24-hour period.
    • Use with caution if you have a history of liver or kidney disease.
    • Call your doctor or nurse if you have:
      • A temperature of 100.4° F (38° C) or higher
      • Black or bloody stool
      • Dizziness
      • Symptoms that last more than 2 days
  • Take pain medication if you have cramping or discomfort in your rectum. Your doctor will tell you what to take and how to take it.

Urinary changes

The lining of your bladder may become irritated during your treatment. About 2 weeks after starting treatment, you may need to urinate frequently and may have a burning sensation when you urinate. You may also feel an urgent need to urinate. Below are guidelines to help you manage these problems.

  • Drink 2 to 3 quarts of liquids throughout the day. If you do not have diabetes, you can drink cranberry juice to help relieve the symptoms.
  • Avoid caffeine, alcohol, pepper, and spicy foods. These may irritate your bladder.
  • Let your doctor or nurse know if you have any urinary changes. Medication can be prescribed.

Sexual health

There is nothing radioactive inside your body. You cannot pass radiation to anyone else, so there is no need to avoid close contact with other people.

You may have concerns about the effects of cancer on your sexuality. The American Cancer Society publishes an excellent resource called Sexuality and Cancer. There is a version available for men and a version available for women. Call 1-800-227-2345 and tell them which version you want.

MSK has a Sexual Health Program to help patients address the impact of their disease and treatment on sexual health. You can meet with a specialist before, during, or after your treatment.

  • Female Sexual Medicine and Women’s Health Program: call 646-888-5076 for an appointment
  • Male Sexual and Reproductive Medicine Program: call 646-888-6024 for an appointment

Information for men

If a woman becomes pregnant with sperm damaged by exposure to radiation, there is a risk of miscarriage or birth defects. If your partner is a female who could become pregnant, use contraception (birth control) throughout your treatment.

It is recommended that you not conceive a child for 2 years after your treatment is completed. If you plan to have children after treatment, you will need to arrange for sperm banking. Please discuss this with your doctor before you begin your treatment.

Sexual changes

During treatment, some men have a burning sensation during ejaculation. In most men, it goes away 1 or 2 months after treatment is finished. Some men develop sexual changes after treatment is finished, including:

  • A decrease in the firmness of the erection.
  • An inability to achieve an erection.
  • A change in the sensation of orgasm.
  • A change in the amount or consistency of the ejaculation.

These changes may occur many months or even years after treatment. They may be permanent, but you will have options to treat them. Your doctor or nurse can give you a referral to a doctor who treats these issues.

If you need more help or support, contact the Male Sexual and Reproductive Medicine Program at 646-888-6024.

Information for women

Vaginal changes

Your vagina may become irritated during your treatment. About 2 weeks after starting treatment, you may notice a vaginal discharge. This may last 2 to 4 weeks after your treatment is completed. Below are suggestions to manage any discomfort.

  • Take sitz baths or tub baths in warm water. Do not stay in the  water longer than 15 minutes at a time. You can take these baths as often as you like for comfort.
  • Use panty liners for increased discharge; do not use tampons.
  • If your labia are itchy and/or irritated, apply the moisturizer your nurse gave you.
  • Check with your doctor or nurse before douching because it may increase the irritation.
  • Check with your doctor or nurse about having vaginal intercourse. You may need to wait for the vaginal tissues to heal. If you are having vaginal intercourse, use a vaginallubricant (such as Astroglide® or K-Y® Jelly) to increase your comfort. Use a condom to help prevent a vaginal infection.

If you need more help or support, contact the Female Sexual Medicine and Women’s Health Program at 646-888-5076.

Hormonal changes

If your ovaries are in the area being treated, your ovarian function may be affected. If you are premenopausal, your periods may stop and you may begin menopause. You may develop symptoms such as hot flashes, insomnia, and mood swings.

Let your doctor or nurse know if these symptoms bother you. They can refer you to a gynecologist to discuss options to decrease these symptoms.


If you are sexually active with a male partner during your treatment, you must use contraception to prevent pregnancy during your treatment. Do not conceive a child until 2 years after your treatment is finished. If you plan to conceive a child after your treatment, please discuss this with your doctor before you begin your treatment.

Skin reactions

During radiation therapy, your skin in the area being treated will change. This is expected, although each person reacts differently.

After 2 or 3 weeks, your skin will become pink or tanned. As treatment goes on, it may become bright red or very dark. It may also feel dry and itchy and look flaky. The skin reactions sometimes become more severe during the week after treatment is completed. If this happens, call your doctor or nurse. These symptoms will gradually decrease about 3 or 4 weeks after your treatment is finished.

Sometimes, the skin in sensitive areas, such as the vagina, groin, testicles, penis, or scrotum, may blister, open, and peel. If this happens, tell your doctor or nurse. If you develop a severe reaction, your nurse will apply special dressings or creams and teach you how to care for your skin. This will gradually heal, but it may take 3 or 4 weeks after your treatment is finished.

Below are guidelines to help you care for your skin during treatment. Follow these guidelines until your skin gets better. These guidelines refer only to the skin in the area being treated.

Keep your skin clean

  • Bathe or shower daily using warm water and a mild, unscented soap. Examples of soaps you can use include Neutrogena®, Dove®, baby soap, Basis®, and Cetaphil®. Rinse your skin well and pat it dry with a soft towel.
  • When washing, be gentle with your skin in the area being treated. Do not use a washcloth or a scrubbing cloth or brush.
  • Do not use alcohol or alcohol pads on the skin in the area being treated.

Moisturize your skin often

  • If you are likely to get a skin reaction, your nurse will recommend that you start using a moisturizer. You should start using it the first day of your treatment to minimize the reaction. If you are not likely to develop a skin reaction, you will not need a moisturizer unless your skin becomes dry or itchy. Your nurse will give you instructions. If you are not sure whether you should use a moisturizer, ask your nurse.
  • You can use over-the-counter moisturizers. When choosing a moisturizer pick one that does not have any fragrances or lanolin. There are a number of products that are good to use, and your nurse may suggest one of these to you. Use only one at a time unless your nurse tells you to use more.
  • If you don’t like the feel of the moisturizer your doctor or nurse recommends, let them know. He or she can select another product for you to try.
  • Apply the moisturizer at least 2 times a day.
    • If your radiation treatment is in the morning, apply it:
      • After your treatment.
      • Before you go to bed.
    • If your radiation treatment is in the afternoon, apply it:
      • In the morning before your treatment.
      • Before you go to bed.

Avoid irritating your skin in the treatment area

  • Wear loose-fitting, cotton clothing over the treated area.
  • Use only the moisturizers, creams, or lotions that are recommended by your doctor or nurse.
  • Do not shave the treated skin, if you can avoid it. If you must shave, use only an electric razor.
  • Do not put any tape on the treated skin.
  • Do not let your treated skin come into contact with extreme hot or cold temperatures. This includes hot tubs, water bottles, heating pads, and ice packs.
  • Do not apply any patches to the treated area, including pain patches.
  • If your skin is itchy, do not scratch it. Ask your nurse for recommendations on how to relieve the itching.
  • If you have no skin reactions, you can swim in a chlorinated pool. However, be sure to rinse off the chlorine right after getting out of the pool.
  • Avoid tanning or burning your skin during and after you are finished with treatment. If you are going to be in the sun, use a PABA-free sunblock with an SPF of 30 or higher. Also, wear loose-fitting clothing that covers you as much as possible.

Hair loss

You may lose some or all of the hair on your pubic area. The hair will usually grow back 2 to 4 months after treatment is finished.


Most patients develop fatigue (i.e., lack of energy, sleepiness, weakness, and not being able to concentrate) after 2 or 3 weeks of treatment. This will gradually go away after your treatment is finished, but can last for several months. There are a lot of reasons patients develop fatigue during treatment, including:

  • The effects of radiation on your body.
  • Traveling to and from treatment.
  • Not having enough restful sleep at night.
  • Not eating enough protein and calories.
  • Having pain or other symptoms.
  • Feeling anxious or depressed.

Some patients find that their fatigue is worse at certain times of the day. Below are suggestions to help you manage your fatigue.

  • If you are working and are feeling well, continue to do so. However, working less may help increase your energy.
  • Plan your daily activities. Pick those things that are necessary and most important to you and do them when you have the most energy.
  • Plan time to rest or take short naps during the day, especially when you feel more tired. You may also find it helpful to go to sleep earlier at night and get up later in the morning.
  • Ask family and friends to help you with shopping, cooking, and cleaning.
  • Some patients have more energy when they exercise. If your doctor approves, try light exercise such as walking.
  • Eat foods that are high in protein and calories.
  • Some patients have symptoms such as pain, nausea, diarrhea, difficulty sleeping, or feeling depressed or anxious. These can all increase your fatigue. Ask your doctor or nurse for help with any other symptoms you may have.

Changes to your blood cell counts

Bone marrow is the substance inside your bones that makes blood cells. You have 3 kinds of blood cells. White blood cells fight off infection. Platelets help your blood to clot when you injure yourself. Red blood cells carry the oxygen you need for energy.

You may have lowered blood cell counts when large areas of bone marrow are in the area being treated. If you are also getting chemotherapy, it can also impact your blood cell count.

We will monitor you throughout your treatment with a blood test called a complete blood count (CBC). If your counts drop, we may stop your treatment until the level increases. We will discuss precautions with you.

If you develop any of the following symptoms, tell your doctor or nurse immediately:

  • A temperature of 100.5° F (38° C) or higher
  • Shaking chills
  • Flu-like symptoms
  • Bleeding

Loss of appetite

Some people find that their appetite decreases during treatment. Your body needs protein and calories to repair the normal cells injured from radiation therapy. Try not to lose weight during your treatment. Below are suggestions to help you maintain your weight.

  • Increase your calories and intake of protein. Your nurse will give you the resource Eating Well During and After Your Cancer Treatment. It has many suggestions for you to try.
  • Try to eat small meals often throughout the day. If you never seem to feel hungry, make a schedule to make sure you eat regularly, for example every 2 hours.
  • Eat your meals in a calm place and take your time. Eat with family or friends whenever possible.
  • Vary the color and texture of your foods to make them more appealing.
  • Bring snacks and drinks with you when you come for treatment. You can have these while you are waiting or while you are coming to and from the department each day.
  • You can drink liquid nutritional supplements if you are not eating enough food. There are many products available and they come in many flavors. Ask your doctor or nurse which product is best for you.

Emotional health

The diagnosis and treatment of cancer can be a very stressful and overwhelming event. You may feel depressed, anxious, confused, afraid, or angry. You may have strong feelings about any permanent changes. These changes can have an impact on your emotional well-being. Help is available for you at any time. If you would like counseling, your nurse can give you a referral to see a social worker, psychiatrist, or counselor.

Also, you may find it comforting to speak with a cancer survivor or caregiver who has been through a similar treatment. Through our Patient-to-Patient Support Program, you have the chance to speak with former patients and caregivers. To learn more about this program, please call 212-639-5007.

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After You Complete Treatment

Please be sure to keep your follow-up appointments with your radiation oncologist. He or she will evaluate your response to treatment. You may have blood tests, x-rays, and scans during these visits. Before coming, write down your questions and concerns. Bring this and a list of all your medications. If you are running low on any medication you need, let your doctor know before you run out. If you have any questions or concerns after your treatment is completed, or in between follow-up visits, call your doctor or nurse at any time.

The MSK Resources for Life After Cancer (RLAC) Program provides support services after your treatment is finished. To learn more about these services, call 646-888-8106 or go to: www.mskcc.org/cancer-care/survivorship/services-survivors.

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