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Managing side effects

Radiation therapy can treat many cancers, but it can also injure healthy cells at or near the treatment area. This can lead to side effects. Before recommending radiation therapy, the radiation oncologist will consider whether the likely benefits outweigh the possible side effects. To minimise side effects, a range of new techniques have made radiation therapy highly precise.

This section provides information and tips to help you manage some common side effects of radiation therapy. These include fatigue, skin problems, hair loss, appetite loss, nausea, mouth and throat problems, bowel and bladder problems, and infertility.

Preparing for side effects

Some people experience many side effects, while others have very few or none. Side effects can vary even among people having the same type of radiation therapy to the same part of the body. Many factors can affect the type and severity of side effects, including:

  • the part of the body treated
  • the type of radiation therapy
  • the dose of radiation needed
  • any other treatments you might be having
  • your general health.

Most side effects that occur during treatment are manageable. Before treatment begins, your radiation therapy team will discuss how to look after the treatment area, the side effects to watch out for or report, ways to manage them, and who to contact after hours if you need help.

If you have severe side effects, the radiation oncologist may change the treatment or arrange a break. They may not recommend these options if it would affect how well the treatment works.

If the side effects are severe, the radiation oncologist may change the treatment schedule or arrange a break. They may not recommend these options if it would affect how well the treatment works.

It is important to maintain your general health during treatment. People who have diabetes need to manage their blood sugar levels to keep them healthy during treatment and recovery – see your GP before treatment starts.

Trying complementary therapies

Complementary therapies are designed to be used along with conventional medical treatments. Therapies such as relaxation and mindful meditation can reduce anxiety and improve your mood.

Let your radiation oncologist know about any complementary therapies you are using or thinking about trying, as some may not be safe. This includes over-the-counter medicines, vitamins and creams, which may affect the way radiation therapy works or make side effects worse. You may also need to avoid massaging the treatment area.

Download our booklet ‘Understanding Complementary Therapies’

How long side effects may last

Radiation therapy can cause side effects during and just after treatment. These are called short term or acute effects. Most side effects go away after treatment. But sometimes radiation therapy can cause long term or late effects months or years down the track.

During treatment, tell your radiation therapy team about any side effects, as side effects can usually be controlled with the right care and medicine.

Short-term side effects

Side effects often build up slowly during treatment and it could be a few days or weeks before you notice anything. Often the side effects are worse at the end of treatment, or even a week or two afterwards, because it takes time for the healthy cells to recover from radiation. Most side effects are temporary and go away in time, usually within a few weeks of treatment finishing.

Long-term or late effects

Radiation therapy can also cause side effects that last for months or years after treatment. These long-term effects are usually mild, they may come and go, and they may not have any major impact on your daily life. However, sometimes they may be more serious. Late side effects may go away or improve on their own, but some may be permanent and need to be treated or managed.

Very rarely, years after successful treatment, patients can develop a new unrelated cancer in or near the area treated. The risk of this late effect is very low, but other factors, such as continuing to smoke or very rare genetic conditions, can increase this risk.

Radiation therapy to the chest, particularly when combined with chemotherapy, may lead to an increased risk of heart problems. Newer radiation therapy techniques have reduced the risk, however, talk to your doctor about your heart health. If you develop heart problems later in life, make sure you let your doctors know you had radiation therapy.

Feeling very tired and lacking energy (fatigue) for day-to-day activities is the most common side effect of radiation therapy to any area of the body. During treatment, your body uses a lot of energy dealing with the effects of radiation on normal cells. Fatigue can also be caused by travelling to daily treatment sessions and other appointments.

Fatigue usually builds up slowly during the course of treatment, particularly towards the end, and may last for some weeks or months after treatment finishes. Many people find that they cannot do as much as they normally would, but others are able to continue their usual activities.

How to manage fatigue

  • Take regular breaks.
  • Plan activities for the time of day when you tend to feel more energetic.
  • Ask family and friends for help (e.g. with shopping, housework and driving).
  • Take a few weeks off work during or after treatment, reduce your hours, or work from home. Discuss your situation with your employer.
  • Do some regular exercise, such as walking. This can boost your energy levels and make you feel less tired. Ask your treatment team about what type of exercise is suitable for you.
  • Limit caffeinated drinks, such as cola, coffee and tea. While caffeine may give a burst of energy, it can make you feel jittery and irritable, and cause insomnia and dehydration.
  • Avoid drinking alcohol. If you smoke, try to quit.
  • Eat a healthy, well-balanced diet, and don’t skip meals.

Download our fact sheet ‘Fatigue and Cancer’

Depending on the part of the body treated, EBRT may make skin in the treatment area dry, itchy and flaky. Your skin may change in colour (look red, sunburnt or tanned) and may feel painful. Skin changes often start 10–14 days after the first treatment. They often get worse during treatment, before improving in the weeks after treatment.

You may need dressings and creams to help the area heal, avoid infection and make you more comfortable. Pain medicine can help if the skin is very sore. Let your radiation therapy team know about skin changes, such as cracks or blisters, moist areas, rashes, infections, swelling or peeling.

Taking care of your skin

  • Clean your skin with warm water and a mild unscented soap. Gently pat skin dry with a soft towel rather than rubbing it.
  • Ask your doctor or nurse what type of cream to use to moisturise the skin.
  • Start moisturising your skin from the first day treatment starts, even before you notice any skin changes.
  • Let temporary skin markings wear off by themselves. Don’t scrub your skin to remove them.
  • Avoid using razors, hair dryers, hot water bottles, heat packs, wheat bags or icepacks on the area that has been treated.
  • Apply sunscreen and wear a broad-brimmed hat when outside. Stay out of the sun where possible.
  • Wear loose, soft cotton clothing. Avoid tight-fitting items, belts, underwire bras, jewellery or collars over the treatment area.
  • Avoid chlorinated swimming pools, and spas and saunas. Check with your doctor about swimming in the sea.

If you have hair in the area being treated, you may lose some or all of it during or just after radiation therapy. The hair will usually grow back a few months after treatment has finished, but it may be thinner or have a different texture. Hair loss may be permanent with higher doses of radiation therapy.

When cancers on one part of the face or head are treated, hair on the other side of the head may be lost temporarily due to radiation passing from one side to the other.

Ways to manage hair loss

  • If you are having radiation therapy to your head or scalp area, think about cutting your hair short before treatment starts. Some people say this gives them a sense of control.
  • Wear a wig, hairpiece or leave your head bare. Do whatever feels comfortable and makes you feel confident.
  • Protect your scalp against sunburn and the cold with a hat, beanie, turban or scarf.
  • If you plan to wear a wig, choose it before treatment starts so you can match it to your own hair colour and style. For more information about wig services, call Cancer Council 13 11 20.
  • Ask your hairdresser or barber how to style your hair. It may be thinner, or curly when it was once straight, and the new growth may be patchy for a while.
  • Contact the Look Good Feel Better program. It helps people manage the appearance-related side effects caused by cancer treatment. Workshops are run for adults and teenagers. Visit lgfb.org.au.

Download our fact sheet ‘Hair Loss’

Some people may lose interest in food or find it difficult to eat well during radiation therapy. This can depend on the part of the body being treated. It is important to try to keep eating well so you get the nutrition you need to maintain your weight. Good nutrition will give you more strength, help manage side effects, and improve how you respond to treatment.

Radiation therapy near the abdomen, pelvic region or head – You may feel sick (nauseated), with or without vomiting, for several hours after each treatment. Your radiation oncologist may prescribe medicine (antiemetic) to take at home before and after each session to prevent nausea. If you are finding nausea difficult to manage, talk to the radiation oncologist or nurse, or call Cancer Council 13 11 20.

Radiation therapy to the head and neck area – Chewing or swallowing may be difficult or painful. Your sense of taste may also change if radiation therapy has affected the salivary glands or tastebuds. In some cases, taste changes may be permanent.

If you are finding it difficult to eat well and get the nutrition you need, a dietitian can suggest changes to your diet, liquid supplements or a feeding tube. Dietitians work in all public and most private hospitals. You can ask your cancer care team if they can arrange an appointment with a dietitian. To find an accredited practising dietitian in your area, visit dietitiansaustralia.org.au.

How to manage appetite changes

Appetite loss

  • Eat 5–6 small meals each day rather than a few large meals.
  • Try to eat extra on days when you have an appetite.
  • Ask for a referral to a dietitian to get advice on what to eat during treatment and recovery.
  • If you don’t feel like eating solid foods, enrich your drinks with powdered milk, yoghurt, eggs or honey.
  • Do not use nutritional supplements or medicines without your doctor’s advice, as some could affect treatment.
  • Cooking smells may put you off eating. It might help if someone else prepares your food, or you could reheat precooked meals.
  • Try to do some light physical activity, such as walking. This may improve your appetite.
  • Let your treatment team know if you are having trouble eating or if your weight has changed

Nausea

  • Have a bland snack (e.g. toast and apple juice) before each session.
  • Try food and drinks with ginger or peppermint to help reduce nausea.
  • Sip on water and other fluids throughout the day to prevent dehydration.
  • Eat dry biscuits, crackers or toast. If nausea is a problem in the morning, have a dry cracker before getting out of bed.
  • Ask your doctor if you can try anti-nausea medicine. Take this as prescribed and tell your doctor if the medicine doesn’t help – it may take some time to find one that works for you.
  • Contact your treatment team if the symptoms of nausea don’t improve after a few days, or if you have been vomiting for more than 24 hours.

Download our booklet ‘Nutrition and Cancer’

Radiation therapy is often used to treat cancers in the mouth, throat, neck or upper chest region. Depending on the area treated, radiation therapy may affect your mouth and teeth. This can make eating and swallowing difficult, and change your sense of taste.

Taste and swallowing changes – You may have thick phlegm in your throat, or a lump-like feeling that makes it hard to swallow. Food may also taste different. Normal taste usually returns in time. Sometimes, swallowing may be affected for months after treatment, but it is rare for problems to be permanent.

Dry mouth and other issues – After treatment, your mouth or throat may become dry and sore, and your voice may become hoarse. Radiation therapy can cause your salivary glands to make less saliva, which can contribute to a dry mouth. These effects will gradually get better after treatment finishes, but it may take several weeks or even months. In some cases, the effects may improve but not completely disappear. Dry mouth (xerostomia) can make chewing, swallowing and talking difficult. A dry mouth can also make it harder to keep your teeth and mouth clean, which can increase the risk of tooth decay.

Teeth problems – Radiation therapy to the mouth may increase the chance of tooth decay or other problems in the future. You will need to have a thorough dental check-up and may need to have any decaying teeth removed before treatment starts. Your dentist can provide an oral health care plan with instructions on caring for your teeth and dealing with side effects such as mouth sores. You will need regular dental check-ups after treatment ends to prevent any problems in the future.

How to relieve mouth and throat problems

  • Have a dental check-up before you start treatment. Ask for a referral to a dentist who specialises in the effect of radiation therapy on teeth.
  • Keep your mouth moist by sucking on ice chips, mints and sipping cool drinks. Carry a water bottle with you.
  • Ask your doctor, nurse or pharmacist for information about artificial saliva to moisten your mouth.
  • Chew sugar-free gum to help the flow of saliva.
  • If you have a dry mouth, you may need to avoid rough, crunchy or dry foods (e.g. chips, nuts, toast, dry biscuits); salty or spicy foods that sting your mouth; or very hot or cold food.
  • Avoid smoking, drinking alcohol or caffeinated drinks, and having citrus or tangy tomato-based food and juice. These things will irritate your mouth and make dryness worse.
  • Ask your doctor for a referral to a speech pathologist. They can suggest ways to modify the texture of foods so they are easier to swallow.
  • If chewing and swallowing are painful, drink liquids using a straw or eat soft or minced textured foods.
  • Ask a dietitian for suggestions on meals and snacks to try.
  • To manage taste changes, add more flavour to food (e.g. add lemon juice to meat and vegetables, marinate foods, use herbs and spices).
  • Talk to your doctor if eating is uncomfortable or difficult. If you are in pain, ask them about pain medicine to help with swallowing.
  • Rinse your mouth often – when you wake up, after you eat or drink, and at bedtime. Ask your doctor or nurse what type of alcohol-free mouthwash to use and how often to use it. They may give you an easy recipe for a homemade mouthwash.

Download our fact sheet ‘Mouth Health and Cancer Treatment’

Download our fact sheet ‘Understanding Taste and Smell Changes’

If you’re having radiation to the pelvic area, the radiation therapists may advise you to drink fluids before each radiation treatment so you have a full bladder. This will expand your bladder and push the bowel higher up into the abdomen, away from the radiation.

Even with precautions, radiation therapy can irritate the lining of the bowel or stomach and affect the way the bowel works. These changes are usually temporary, but for some people they are permanent and can have a major impact on quality of life. It is important to talk to your treatment team if you are finding bowel issues difficult to manage.

Diarrhoea – This is when you have frequent loose, watery bowel motions. Diarrhoea can also cause abdominal cramping, wind and pain. After radiation therapy, you will need to go to the toilet more urgently and more often. Having diarrhoea can be tiring, so rest as much as possible and ask others for help. Diarrhoea can take some weeks to settle down after treatment has finished.

Radiation proctitis – Radiation therapy to the pelvic area can damage the lining of the rectum, causing inflammation and swelling known as radiation proctitis. Symptoms may include blood and mucus in bowel motions; discomfort opening the bowels; or the need to empty the bowels often, perhaps with little result. Ask your treatment team about your risk of developing radiation proctitis. Radiation proctitis is usually short term but may be ongoing in a small number of people. If you have any ongoing problems, they may refer you to a gastroenterologist.

How to manage bowel changes

  • Ask your doctor about suitable medicines for diarrhoea. Take as directed.
  • Check with your treatment team before taking any over-the-counter or home remedies, as taking them with anti-diarrhoea medicines may cause unwanted effects.
  • Drink peppermint or chamomile tea to reduce abdominal or wind pain.
  • Eat or drink as well as you can to give your body the nutrients it needs.
  • Do some gentle exercise, such as walking, to encourage healthy bowel movements. Check with your doctor about the amount and type of exercise that is right for you.
  • Avoid alcohol and cut down on coffee, cola and other drinks that contain caffeine.
  • Drink plenty of clear liquids when you first notice symptoms of diarrhoea. This helps to avoid dehydration and replaces fluids lost through diarrhoea. Try apple juice, weak tea, clear broth, sports drinks and electrolyte-replacing fluids. It may also be worth trying a lactose-free milk.
  • Choose plain foods that are low in insoluble fibre (e.g. bananas, mashed potato, apple sauce, white rice or pasta, white bread, steamed white fish or chicken). Talk to your dietitian about what else you can eat.
  • If you have diarrhoea, avoid high-fibre, fatty or fried foods; pulses; garlic and onion; and rich sauces and gravies, as these can make diarrhoea worse.
  • Contact your treatment team immediately if there is blood in your bowel motions or if you have more than 5–6 bowel movements in 24 hours.

Radiation therapy to the abdomen or pelvic area can irritate the bladder or, more often, the urethra (the tube that carries urine from the bladder to the outside of the body).

Cystitis – You may feel you want to pass urine more often or you might have some stinging when you pass urine. This is called cystitis. The symptoms usually ease within 3 months of finishing radiation therapy.

Urinary incontinence – Incontinence is when urine leaks from your bladder without your control. After radiation therapy, you may need to pass urine more often, particularly at night, or feel as if you need to go in a hurry. You may leak a few drops of urine when you cough, sneeze, laugh or strain.

Ways to manage bladder changes

Strengthening the pelvic floor muscles can help with bladder control. Ask your doctor for a referral to a continence nurse or physiotherapist, or contact the National Continence Helpline on 1800 33 00 66 or at continence.org.au.

Let your treatment team know if you have bladder or urinary problems, as they will be able to suggest strategies and may recommend medicines. To help manage these side effects, drink plenty of fluids, limit strong coffee and tea, and avoid drinking alcohol.

The blood vessels in the bladder and bowel can become more fragile after radiation therapy. This may mean you see blood in your urine or bowel motions, even months or years after treatment. Always let your doctor know if you notice new or unusual bleeding.

Lymphoedema is swelling that occurs in soft tissue. If lymph nodes or lymph vessels have been damaged during radiation therapy, lymph fluid may not drain properly. If lymph fluid builds up, it can cause swelling in the area being treated. Lymphoedema usually occurs in an arm or leg, but can also affect other parts of the body. The main signs of lymphoedema include swelling, redness and skin warmth, which may come and go.

People who have had surgery followed by radiation therapy are more at risk. Lymphoedema or swelling is sometimes just a temporary effect of radiation therapy, but it can be ongoing. It can also be a late effect, appearing months or even years after treatment.

Ways to manage lymphoedema

Lymphoedema is easier to manage if the condition is treated early. Treatment will aim to improve the flow of lymph fluid. It is important to avoid pressure, injury or infection to the affected part of your body, and to see your doctor if you have any signs of lymphoedema.

Some hospitals have specialist physiotherapists who can teach you simple exercises to reduce your risk of developing lymphoedema or show you ways to manage it if you have developed it. There are also outpatient and private lymphoedema practitioners.

Lymphoedema practitioners can develop a personalised treatment program. This may include exercises, skin care, lymphatic drainage massage and compression garments, if needed. To find a lymphoedema practitioner, visit the Australasian Lymphology Association.

Download our fact sheet ‘Understanding Lymphoedema’

Radiation therapy can affect your sexuality and fertility in emotional and physical ways. These changes are common. Some changes may be temporary, while others may be permanent.

Changes in sexuality

You may notice a lack of interest in sex or a loss of desire (libido), or you may feel too tired or unwell to want to be intimate. You may feel less sexually attractive to your partner because of changes to your body. All of these feelings are quite common. Radiation therapy can also make sexual intercourse uncomfortable, depending on where the radiation therapy is given. Talk to your doctor about ways to manage side effects that change your sex life.

Using contraception

A woman’s eggs (ova) and a man’s sperm can be affected by very small amounts of radiation when having radiation therapy to any part of the body. Depending on the type of radiation therapy you have, your doctor may talk to you about using a barrier method of contraception (such as a condom or female condom). If pregnancy is possible, your doctor will advise you to avoid pregnancy by using contraception during radiation therapy and for at least six months after you have finished treatment. Talk to your doctor as soon as possible if pregnancy occurs.

Changes in fertility

The risk of infertility (difficulty getting pregnant or conceiving a child) will depend on the area treated, the dose of radiation therapy and the number of treatment sessions. If you are treated with both radiation therapy and chemotherapy (chemoradiation), the risk of infertility is higher.

Radiation therapy to the pelvic area, abdomen and sexual organs can affect your fertility, which can be temporary or permanent. Radiation therapy to the brain can damage the pituitary gland, which controls the hormones the body needs to produce eggs or sperm.

If infertility is a potential side effect, your radiation oncologist will discuss it with you before treatment starts. Let them know if you think you may want to have children in the future. Ask what can be done to reduce the chance of problems and whether you should see a fertility specialist beforehand. Sometimes, however, it is not possible to properly treat the cancer and maintain fertility.

Many people feel a sense of loss when they learn they may no longer be able to have children. If you have a partner, talk to them about your feelings. Talking to a counsellor may also help.

Effects on fertility and sexual function

Radiation therapy to the abdomen, pelvis and reproductive organs can affect your sexual function and ability to have children.

Changes to the vagina

  • Radiation therapy to the vulva or vagina may cause inflammation, making intercourse painful. This usually improves in the weeks after treatment  ends. Your treatment team will recommend creams and pain relief to use until the skin heals.
  • Talk to your doctor about using vaginal moisturisers, which may help with discomfort. In some cases, oestrogen creams are prescribed.
  • The vagina may become shorter and narrower (vaginal stenosis), making intercourse difficult or painful. Having regular intercourse or using vaginal dilators after treatment ends can help keep the vagina open. Wait until any soreness or inflammation has settled before you start using a dilator or having sexual intercourse. This is usually 2–6 weeks after your last session of radiation therapy. Using a dilator can be challenging. Your doctor, nurse or a physiotherapist can provide instructions.
  • If sexual penetration is painful or difficult, explore other ways to orgasm or climax.

Menopause

  • Radiation therapy to the pelvic area or abdomen usually stops the ovaries producing female hormones, which leads to early menopause.
  • Your periods will stop and you may have menopausal symptoms. These may include hot flushes, dry skin, vaginal dryness, mood swings, trouble sleeping (insomnia) and tiredness.
  • If vaginal dryness is a problem, take more time before and during sex to become aroused. Using lubrication may also make intercourse more comfortable.
  • Discuss changes to your libido with your partner so they understand how you’re feeling.
  • Ask your GP to arrange a bone density test to check for osteoporosis or osteopaenia, which can develop after menopause.
  • Talk to your doctor about ways to manage the symptoms of menopause. If you need support resuming sexual activity, ask your doctor for a referral to a sexual therapist or psychologist.

Sperm production and erection problems

  • Radiation therapy to the pelvic area or near the testicles may temporarily affect how much sperm you make. This is called a dry orgasm. You may feel the sensations of orgasm, but ejaculate little or no semen. Semen production often returns to normal after a few months.
  • Depending on the dose and the area of the pelvis treated, you may have trouble getting and keeping an erection firm enough for intercourse. This is called erectile dysfunction or impotence. Ejaculation may be painful for a few weeks after treatment. Sometimes impotence may be permanent.
  • Talk to your treatment team if erection problems are ongoing and causing you distress. They can suggest ways to keep your penis erect, such as prescription medicines, penile implants or vacuum erection devices.

Infertility

  • Sometimes, changes to sperm production and ability to have erections are permanent. This may cause infertility. If you want to have a child, you may wish to store sperm before treatment starts so your partner can conceive through artificial insemination or in-vitro fertilisation in the future.
  • If radiation therapy causes menopause, you will no longer be able to become pregnant. If you wish to have children in the future, talk to your radiation oncologist before treatment starts about ways to preserve your fertility, such as storing eggs or embryos or freezing ovarian tissue.
  • If your ovaries don’t need to be treated, one or both of the ovaries may be surgically moved higher in the abdomen and away from the field of radiation. This is called ovarian transposition or relocation (oophoropexy). It may lower the amount of radiation you receive and it may help the ovaries keep working properly.

Download our booklet ‘Sexuality, Intimacy and Cancer’

Download our booklet ‘Fertility and Cancer’

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This information is reviewed by

This information was last reviewed December 2021 by the following expert content reviewers: Prof June Corry, Radiation Oncologist, GenesisCare, St Vincent’s Hospital, VIC; Prof Bryan Burmeister, Senior Radiation Oncologist, GenesisCare Fraser Coast, Hervey Bay Hospital, and The University of Queensland, QLD; Sandra Donaldson, 13 11 20 Consultant, Cancer Council WA; Jane Freeman, Accredited Practising Dietitian (Cancer specialist), Canutrition, NSW; Sinead Hanley, Consumer; David Jolly, Senior Medical Physicist, Icon Cancer Centre Richmond, VIC; Christine Kitto, Consumer; A/Prof Grace Kong, Nuclear Medicine Physician, Peter MacCallum Cancer Centre, VIC; A/Prof Sasha Senthi, Radiation Oncologist, The Alfred Hospital and Monash University, VIC; John Spurr, Consumer; Chris Twyford, Clinical Nurse Consultant, Radiation Oncology, Cancer Rapid Assessment Unit and Outpatients, Canberra Hospital, ACT; Gabrielle Vigar, Nurse Unit Manager, Radiation Oncology/Cancer Outpatients, Cancer Program, Royal Adelaide Hospital, SA.