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External radiotherapy treats cancer by using doses of high-energy x-rays to destroy the cancer cells while doing as little harm as possible to normal cells.
The treatment is usually given every weekday in the hospital radiotherapy department, with a rest at the weekend. You may sometimes have treatment more than once a day, and occasionally you may also have treatment at the weekend.
It's important to follow the scheduled treatment plan and avoid any unnecessary gaps in your course of treatment. The treatment will usually last 3–7 weeks, depending on the type and size of the cancer. Your radiotherapy doctor (clinical oncologist) will discuss the treatment with you.
Conformal radiotherapy (CRT) is the most common type of external radiotherapy used for the treatment of head and neck cancers. A special attachment to the radiotherapy machine carefully arranges the radiation beams to match the shape of the cancer. Shaping the radiotherapy beams reduces the radiation received by surrounding healthy cells. This can reduce the side effects of the radiotherapy treatment (such as a dry mouth|) and may allow higher doses to be given, which could be more effective. Another type of radiotherapy known as intensity-modulated radiotherapy (IMRT), which is similar to conformal radiotherapy, may be used in some hospitals.
To ensure that the radiotherapy is as effective as possible, it has to be carefully planned by a clinical oncologist. It’s a very precise treatment and it’s important that you are able to lie still, in exactly the same position, for each treatment.
To help you do this, you may need to wear a see-through Perspex® or plastic device called a 'mould', ‘shell' or ‘mask' that helps to keep your head and shoulders as still as possible. The mould allows you to see and breathe normally, but it may make some people feel claustrophobic. It’s important to let the doctor or nurse know if you suffer from claustrophobia. You will only have the mould in place for a few minutes at a time, and most people soon get used to wearing it.
You may need to wear a clear, plastic mask for a few minutes at a time, to hold your head still during treatment.
Your mould will be made on one of your first visits to the radiotherapy department. The radiographer (the person who gives the treatment) will explain the whole process to you before starting.
We have more information about radiotherapy masks|.
Treatment planning is a very important part of radiotherapy and several visits may be needed.
You will have a CT (computerised tomography) scan taken of the area to be treated. A CT scan takes lots of images from different angles to build up a three-dimensional picture of the area. At the same time radiographers will take measurements from you which are needed for treatment planning. This session will usually take about 45–60 minutes and you will need to wear your radiotherapy mould.
Sometimes you may also need to go to the hospital’s scanning department to have an MRI scan. This uses powerful magnetic fields to give a detailed picture of part of your body, which can give additional useful information.
The radiographer’s measurements and the information from the scans are fed into the radiotherapy planning computer to help your doctors plan your treatment more precisely.
Marks are drawn on the mould (or sometimes on your skin) to help the radiographer position you accurately, and show where the rays are to be directed. If the marks are on your skin they must stay there throughout your treatment, but they can be washed off once your course of treatment is finished. Sometimes a few small, permanent marks (tattoos) may be made on your skin. The marks are tiny and will only be done with your permission.
At the beginning of your treatment you’ll be given instructions on how to look after the skin in the area being treated. You will be told whether you can wash the marked areas of skin.
Very occasionally, radiotherapy to the mouth or throat can cause swelling to the surrounding tissue which may make it difficult for you to breathe during the treatment.
If this is likely to happen, your doctors will arrange for you to have a tracheostomy| before your radiotherapy treatment starts. The tracheostomy is usually temporary.
Before each session of radiotherapy, the radiographers will position you carefully on the couch, with the mould fitted, and make sure you are comfortable. During your treatment, which only takes a few minutes, you will be left alone in the room, but you’ll be able to signal to the radiographers who will be watching you from the next room.
You will have to lie still while the treatment is given, but you will not feel the radiotherapy; it’s similar to having an x-ray.
External radiotherapy does not make you radioactive, and it’s perfectly safe for you to be with other people, including children, throughout your treatment.
Radiotherapy can cause some temporary side effects. Although these may be worse if you have your treatment combined with chemotherapy|, they will usually gradually disappear after the treatment has finished.
If you continue to smoke during your treatment these side effects are likely to be worse, so if you can stop smoking this will help your recovery.
You may have some of the side effects listed below:
The skin over your face and neck is very likely to gradually redden or darken and become sore (like sunburn). This starts after about two weeks of treatment and may last for 2–4 weeks after the treatment has finished. Sometimes the skin will peel or break. The radiotherapy team will tell you how to look after your skin as some chemicals can make the skin more sensitive to radiation. It’s very important to use only soaps, creams and lotions that are recommended by the radiotherapy staff.
Rarely, the skin in the treated area may break down and become moist. The radiotherapy team can give you advice if this happens.
Your mouth and throat will probably become sore and inflamed after a couple of weeks of treatment and you may develop some mouth ulcers. Your voice may also become hoarse. You may become sensitive to very strong flavours and possibly to extreme heat and cold. Eating food may become difficult and swallowing painful.
You will be given advice on how to look after your mouth during your treatment. It’s important to follow this advice. Your doctor can prescribe mouthwashes and protective gels that coat the lining of the mouth, and painkillers to help ease any discomfort.
Your specialist nurse or dietitian will advise you on how to change your diet to make eating more comfortable|. For example, you’ll be encouraged to eat soft food and to avoid smoking, drinking spirits and eating hot or spicy foods. Drinking plenty of bland, cool fluids like milk and water, or sucking ice cubes, will help to keep your mouth moist. You’ll be able to discuss any problems with eating and drinking with a specialist nurse or dietitian.
Once the course of radiotherapy has finished, your mouth will gradually heal and most people get back to eating normally a few weeks after the treatment has finished. However, the effects of the radiotherapy occasionally make the throat too uncomfortable for a person to eat or drink and they may need to be fed by a nasogastric or a gastrostomy tube| during the treatment and for a period of time after treatment has finished.
If part, or all, of your mouth is treated, your sense of taste will quickly change during the radiotherapy. Some people either lose their sense of taste completely or find that everything tastes the same (usually rather metallic or salty, or like cardboard). Although your sense of taste should recover, it may take many months for it to return to normal after the treatment.
Some people lose their appetite as a general effect of radiotherapy. A sore, dry mouth can also make eating difficult. If you are eating less, it’s a good idea to supplement meals with nutritious high-calorie drinks such as Complan® and Build-up® (these are available on prescription or can be bought from a pharmacy or some larger supermarkets). You could also try baby foods, which are soft but also high in protein and calories.
If you’re unable to eat solids your doctor or nurse may prescribe supplement drinks, such as Ensure® or Fortisip®, which are complete meals in liquid form.
You will be able to discuss any problems with your diet with the dietitian or specialist nurse at the hospital.
We can provide you with more information and helpful tips on how to eat well when you have lost your appetite|.
You may notice that you can’t produce as much saliva as before the treatment. The lining of your mouth and throat may become dry and this can make eating and speech difficult. You may also notice a feeling of sticky mucus in the throat, as sometimes radiotherapy makes the saliva thick and stringy, which can be very distressing. To reduce the dry feeling, you may find it helpful to drink fluids regularly and to use an artificial saliva spray. Wiping small amounts of vegetable or olive oil on the inside of your cheeks may also help.
Although you may start to produce some saliva again within a few months of treatment, it’s important to be aware that the problem might continue for some time. If your mouth, throat or the upper part of your neck is being treated, your mouth may become permanently dry.
We have more information about coping with a dry mouth|.
During your treatment you will need to see your dentist regularly, because your mouth may become drier, more sensitive and easily irritated. You may also be more prone to tooth decay. You should follow the dental hygiene advice that you are given, such as brushing regularly with a soft toothbrush or gauze. You will usually be asked to apply fluoride gel to your teeth every day, either as a mouthwash or in special gum shields, to help protect your teeth from decay.
If your dentist recommends that one of your teeth needs to be removed, you should be referred to a specialist oral and maxillofacial surgeon for advice and treatment.
For most people, radiotherapy for cancers of the head and neck will not make their hair fall out, or the amount of hair loss| will be very slight. It’s unusual to lose any hair from the scalp during radiotherapy for head and neck cancers, as hair only falls out where the x-ray beam enters and leaves your body. For most people this will be limited to parts of the face and neck. Only the hair very close to the tumour is likely to be permanently lost, so men will lose their beard permanently in those areas of skin that become red or dark and sore during treatment. Hair loss can occur when tumours around the eyes and ears are treated.
Your doctor will advise you if permanent hair loss is likely in your case, and can tell you where it is likely to occur.
You may find that the treatment makes you feel very tired|. During your treatment it’s important to get as much rest as you can, especially if you have to travel a long way each day for your treatment.
Sickness| is more likely to affect people who have combined chemotherapy and radiotherapy treatment. If it’s a problem your doctor can prescribe anti-sickness medicines (anti-emetics).
If you have radiotherapy to the back of your throat (nasopharynx), the muscles used to open and close your mouth can become stiff.
You will be shown mouth-opening exercises that you should do at least twice a day. There are also specialist aids available to help you exercise your jaw. Your doctor, specialist dentist, or speech and language therapist can give you advice about exercises and where to buy an exercise aid. Information is also available from the organisation Saving Faces|.
This is usually caused by changes to your saliva and it can be reduced by regular mouth care and mouthwashes. It may also be caused by an infection in your mouth, which is common during radiotherapy treatment. If you have bad breath let your doctor or specialist nurse know. They can look inside your mouth to see if you have an infection, which can then be treated with antibiotic or antifungal medicine.
All these side effects can be upsetting and difficult at times. However, it’s helpful to remember that many are temporary and will gradually disappear.
Most side effects occur towards the middle and end of the course of treatment and continue during the first couple of weeks after your treatment has finished. The effects can be mild or more troublesome, depending on the dose of radiotherapy and the length of your treatment. Your doctor or specialist nurse will be able to advise you on what to expect, and can offer treatment and support to help relieve any side effects.
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If you have any questions about cancer, need support or just want someone to talk to, ask Macmillan.