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Radiotherapy - General Information

This booklet will help you understand what will happen when you come to Velindre hospital to have radiotherapy treatment. 

The booklet will explain how your treatment is planned and given. It will discuss side effects you may have and will tell you how to get more information and support. 

A glossary is provided at the front of this booklet to help you understand any words that you may find unfamiliar. 

Contact telephone numbers are given at the end of the booklet.

We hope this answers your questions. Please ask us if you have other questions that we have not covered.

Please bring a list of all the medication you are taking every time you come to Velindre.

Patient information is available on the Velindre website
Please go to: 

Smoking is not allowed within the grounds and inside Velindre hospital. If you need help giving up please ask us.

This information is evidence based and is reviewed annually

Glossary of terms

CT (computerized tomography) scanner - a machine that uses x-rays to take detailed scans of your body

Linear Accelerator (LA) - a machine that uses high energy radiation to give radiotherapy treatment

Physicist - a person who does the technical planning of
radiotherapy treatment

Dietitian - a person who helps patients to choose the best food to keep them healthy and strong 

What is radiotherapy?

Your doctor has decided you would benefit from a course of radiotherapy treatment.

Radiotherapy is a treatment for cancer using high energy radiation, usually x-rays. The type and amount of radiation that you receive is carefully calculated to damage the cancer cells. This stops them from dividing properly so they are destroyed. Your treatment is planned to avoid as much healthy tissue as possible. However some healthy tissue is affected which causes side effects. 

Radiotherapy treatment can be given alone, after or instead of surgery. It can also be given before, with or after chemotherapy or hormone treatment.

Radiotherapy team looking after you

The doctor responsible for your care is called a Clinical Oncologist. They will prescribe your radiotherapy treatment. This will be planned by a team of physicists and planning radiographers. The therapeutic radiographers will give you your treatment.

Velindre is a teaching hospital so your team may include a student radiographer, student nurse or a medical student. Please tell us if you don't want a student present during your clinic or treatment appointment.

We will ask your name, address and date of birth every time you come to the radiotherapy department. This is to avoid any confusion. 

During your treatment you may be seen by the information, support and review team. The team includes specialist radiographers with extra training to advise you on how best to deal with any side effects. They can also prescribe medication to help. They will provide information and advice on any practical, financial or emotional concerns you may have. You can speak to them at any point during treatment; their number is at the end of this leaflet.

How many treatments will I need?

Radiotherapy is normally given Monday to Friday as an outpatient. The number of treatments you will need depends on many facts about you and your particular type of cancer.  Your doctor will decide how many treatments are best for you.

Having chemotherapy with radiotherapy

We will explain your chemotherapy and give you separate leaflets if you are having this treatment. 

Transport to and from Velindre

Hospital transport is available but most people use their own transport. If you would like to use hospital transport, please give us as much notice as possible to arrange this for you. There is a high demand for transport so you will need to be prepared to wait for some time to be picked up and taken home. Spaces are limited so please consider travelling alone. Some local support groups can also arrange transport. Also, patients on particular benefits can claim travelling expenses, please ask when you come for your treatment.

Planning your radiotherapy treatment

Radiotherapy treatment is planned for each patient individually. We will give you an appointment in the planning department. This is at the front of Velindre hospital. 

You may see your doctor to discuss the benefits and risks of radiotherapy. They will ask you to sign a consent form if you haven’t already. It is your decision to go ahead with this treatment, so please discuss any concerns with your doctor before you sign the consent form.  

If you have already signed your consent form for treatment you may only see the planning radiographers who will explain everything that is going to happen to you.

Mould room

If you are having treatment to your head or neck we may need you to wear a special mask to keep your head still. You will wear your mask for your planning CT scan and your treatment. You may be asked to go to mould room to have your mask made or it may take place at your CT scan. We will give you more information about the mould room if you need to go there.

CT planning scan

Most people will need to have a CT scan. This scan helps your doctor have a detailed picture of the area that needs treatment. The scan usually takes about 20 minutes. 

typical CT scanning machine
Picture of the CT scanner

We may ask you to take off some of your clothing depending on which part of the body we are treating. You will be given a gown to wear to keep you covered up. We will ask you to lie on the couch. Please tell us if you are not comfortable because you will need lay in this position, breathing normally, during your scan and for each day of your treatment. 

If you find it uncomfortable or painful to lie flat we advise you to take some pain relief before your scan as the couch is very hard. Please bring your painkillers with you for your planning appointment and your treatment appointments just in case you need them.

You will not see or feel anything during the scan. The radiographers will leave the room to turn the scanner on, but they will watch you very closely through a large window.

We may need to draw some marks on your skin as reference points for your treatment. We will ask your permission to permanently mark these points. We will make a tiny dot by using the tip of a sterile needle to place black ink just under your skin. It is a permanent mark but is as tiny as a freckle.  This will mean we have accurate marks to position you for your treatment every day, so you are able to wash during treatment.

Radiotherapy ink dot mark
A picture of a permanent skin mark

Starting your radiotherapy treatment

You may start your treatment the same day or there can be a few days or weeks between your planning scan and the start of your treatment. This can depend how urgent the doctor feels your treatment is. Time is needed to plan your treatment and this will be booked when the next available slot is available on your treatment machine.

Please let us know if there is any time that you would not be able to come for treatment. We will take this in to account when we book your treatment. Please tell us if you have any special needs that may affect your appointments, such as: 

  • needing transport
  • having any other treatment (chemotherapy for example)

We will send you a letter or call you with your first appointment. We will give you the rest of your appointments when you come for your first treatment.

If you have a problem with the appointment, please phone the radiotherapy booking clerk as soon as possible. If the answer machine comes on, please leave your name and phone number slowly and clearly. We will ring you back as soon as possible.

Your first radiotherapy treatment

If you are an outpatient when you come for your treatment, please come to the radiotherapy entrance which is around the back of Velindre hospital. Give your name and hand your letter to the receptionist in the radiotherapy waiting room. They will tell you where to sit and wait or direct you straight to your treatment machine. 

If you are an in-patient, one of the hospital porters will normally collect you and take you to the treatment machine.  You may be treated at any time in the day, depending upon when there is a free slot on the treatment machine.

Your radiographers will chat to you before you go in for your first treatment. We will explain what will happen during your treatment and tell you about the possible side effects you may experience. We will give you advice about skin care during your treatment.  Please ask any questions you have about your treatment. We may need you to re-sign your consent form before you have your first treatment.

Occasionally unforeseen machine breakdowns can happen during your treatment. This may cause delays or cancellation of your appointment on that day. We will explain this to you in more detail on your first day.

During your radiotherapy treatment

You may have your radiotherapy treatment on either the DXR (deep x-ray) or a linear accelerator (LA for short). The linear accelerators each have a number, so for example, you may have your treatment on LA 4 or LA 5. The LA machines may look and sound different but they give the same treatment.

In the treatment room, we will ask you to lie or sit in the same position you were in for your planning scan. We will position you carefully using the reference marks we made at planning. When you are in the correct position, we will ask you to lie or sit still and breathe normally. We will leave the room to switch the machine on but are watching you all the time.

If you are having your treatment on the DXR machine, the end of the machine will gently touch your skin. The DXR machine does not make a noise.

Radiotherapy DXR machine
Patient having treatment on DXR machine

If you are having treatment on a linear accelerator, the machine can be controlled and moved to the different treatment angles outside the room. When the machine is moving, it may come close to you but it will not touch you. When the machine is switched on you won’t feel anything, but you may hear it buzzing. 

LA treatment machine at angle
Patient having treatment on the Lin Acc 

The radiographers will watch you carefully on television monitors. If you feel uncomfortable while the machine is on please wave your hand. We can switch the machine off and restart the treatment when you are comfortable again.
You will need to lie or sit still on the treatment couch for about 10 - 15 minutes. When your treatment is finished, please stay still until the radiographers say you can move. 

Side effects of radiotherapy

The side effects you may experience will depend on which part of the body we are treating and how much treatment you have. Everyone’s reaction is different. Side effects only affect the part of the body that we are treating. Your doctor will tell you the specific side effects that you may expect. 

If you receive just one treatment, side effects can develop within 48 hours. If you are having 5 or more treatments, they normally develop near the end of treatment. 

Radiotherapy continues to work inside your body for about 2 weeks after you have finished your treatment so any side effects you experience will continue for this time also. After about 2 weeks you will start to feel better, everybody’s recovery time is different.


Radiotherapy can make you feel more tired than usual. You should listen to your body and rest if you need to but continue your normal activities if you feel able. Some people find a little exercise; such as walking can help their tiredness.  

Skin reaction

Your skin within the treatment area may turn pink, feel warm and tender; also can be dry and itchy. We encourage you to continue your normal skin care routine during treatment; we will discuss skincare with you on your first treatment.

Side effects of radiotherapy to your neck

If you are having treatment to your neck, your throat will become sore and you may have trouble swallowing some foods. We can give you medication to help soothe your throat and suggest a soft food diet. Please ask your radiographers for advice.

Side effects of radiotherapy to your mouth

Side effects of having treatment to your mouth include:  

  • Your mouth may become dry and sore 
  • You may develop ulcers 
  • Your saliva may become thick and stringy
  • You may have difficulty chewing 
  • You may notice your taste changes  

We will give you a mouthwash to keep your mouth clean during treatment. We will advise you how to care for your mouth and teeth or dentures. 

If you smoke, we recommend you stop. If you drink alcohol, you should try to reduce the amount you drink. This will help you manage the side effects.

If you are struggling with eating, please tell your radiographers, so we can refer you to see a dietitian.

Side effects of radiotherapy to your chest

You may develop a cough, or start to cough more than usual and you may become more breathless.

You may notice some difficulty or soreness swallowing. We can give you medication to help. If it occurs during your treatment please tell your radiographer. If it occurs after your treatment please tell your specialist nurse or ring the review team for advice (their number is at the back of this booklet).

If you have just one or two treatments to your chest, you may notice pain or increased pain in your chest. You may develop flu like symptoms such as a temperature or a fever, which causes sweating. This will settle during the first 2 days after treatment. Pain relief can help so please speak to the review radiographers for further advice.

Side effects of radiotherapy to your brain

Radiotherapy to your brain may cause headaches and you may feel sick. Please tell your radiographers if this happens. There is medication that can help reduce these side effects.

Radiotherapy will cause hair loss on your head. This may happen during or after you have finished your treatment. Your hair may grow back 2 – 3 months after you finish your treatment. We have a leaflet that tells you more on coping with hair loss. Please ask your radiographer if you would like a copy. During your treatment you should wash and brush your hair gently. Use a mild shampoo such as a baby shampoo. 

Side effects of radiotherapy to your abdomen and pelvis

Treatment to your abdomen or pelvis may cause diarrhoea and increased wind. Please ask your radiographer for advice on how to manage this. 

The treatment may irritate your bladder and cause symptoms such as pain or burning when you pass water. You may find you need to pass water more often. We advise you to drink lots of water to help. Please tell your radiographers if you are having any of these symptoms.

You may also feel sick. Drinking lots of fluids may help. We can give you anti-sickness medicine if you need it.

Side effects of radiotherapy to your bones

You may experience an increase in pain (‘a pain flare’) in the area we have treated. It is important to have good pain relief during this time. Please speak to your radiographers, doctor or specialist nurse to prescribe any more medication you may need. It can take a few weeks for the pain to improve.

Long term side effects

There can be some long term side effects which can become permanent. Your doctor will discuss these with you before you start treatment.

Finishing your treatment

Towards the end of your treatment we will give you an appointment for a follow up at a clinic with your doctor. This may be a few weeks to months after you finish your treatment. We will advise you of this time frame when you finish your treatment. We will give you the names and telephone numbers of your review radiographers. Please ring the review radiographers if you are worried about any side effects after you have finished. Their number is also at the end of this leaflet.

Community support

Your doctor may have discussed having extra support at home. If you would like this support and it hasn’t been organised yet, please contact the information, support and review team. 

Other support services and information can be accessed through Tenvous or Macmillan. Their details are at the end of this leaflet.

Contact telephone numbers

Velindre Hospital                         029 2061 5888

Radiotherapy booking clerks        029 2019 6836

Information, support + review team 029 2061 5888 ext 6421

Transport from Aberdare: The Rowan Tree 01443 479369

Transport from Bridgend: Sandville    01656 743344 

Transport from Merthyr: Cancer Aid     01685 379633

Helplines and websites

Helpline:     0808 808 1010 

Macmillan cancer support                    
Helpline:           0808 800 0000 

Stop Smoking Wales                
Helpline:        0808 250 6053

F.PI 1                         Issue 16                July 2