3D bolus is a type of plastic material used to shape the radiation beam during each treatment session. This enables your care team to maximum dose to the treatment area while minimising dose to underlying healthy tissue, improving the accuracy and safety of treatment.

Before your treatment, you’ll be fitted with a personalised 3D bolus that fits exactly over the area being treated. For this complex process, we use the latest 3D printing and a special material which will evenly distribute the radiation across the target skin field.

First appointment

The appointment will take between 30 and 60 minutes and will involve a computed tomography (CT) scan. This is used to develop your personalised 3D bolus that’s needed during each treatment session.

1. Your radiographer will position you for your CT scan using equipment to keep your treatment site still. For treatment to your head and neck, this will be a plastic (“thermoplastic”) mask (made at a second CT appointment) and for other treatment sites you’ll be positioned using vacuum formed bags
2. Your area(s) to be treated will be marked on the skin with pen and any ‘boost areas’ – where there is a cancer within the field – will also be marked
3. Next, your radiographer will take photographs of the area(s) to be treated
4. Your radiographer will then put wire over your markings, so the area can be seen on the CT scan
5. Once you’re comfortable, the CT scan can begin. You may need more than one scan if you’re having multiple sites treated
6. Once the scanning is complete, you can go home

Second appointment

You’ll come back for your second planning appointment one or two weeks later, once your 3D bolus is ready.

1. You’ll be positioned as you were for your first CT appointment, but this time with the 3D bolus in place over the area(s) to be treated. If you’re having an area on your head treated, the radiographers will also make a thermoplastic mask at this point, in order to keep your head still during your treatment sessions
2. Once you’re comfortable, the CT scan can begin. You may need more than one scan if you’re having multiple sites treated
3. Once the scanning is complete, you can go home

Your consultant will use your CT scans and advanced computer technology to create a treatment plan. They will outline the treatment site(s), the boost areas, and any organs that are in close proximity to these sites on the plan so they know where to target the dose.

Once your treatment course has finished, you’ll attend a number of follow-ups at GenesisCare until any skin side effects have settled. You’ll also have a consultation four to six weeks after the completion your treatment or as needed, and then three, six and 12 months after.

Common short-term side effects that occur in the treatment area include:

• Skin soreness
• Skin breakdown (oozing and scabbing)
• Hair loss
• Swelling
• Pain

You may also experience mucosal soreness if you’re being treated near your eyes, nose or mouth. This might include dry eyes, an inflamed and sore nose, or dry lips and mouth and mouth ulcers.

You may notice that the appearance of your skin will get worse before it gets better, but this is part of the normal healing process.

Common long-term side effects occurring in the treatment area include:

• Permanent skin changes (texture and colour - including redness if you have white skin, darkening or discolouration of the skin if you have brown or black skin)
• Telangiectasia (formation of small but prominent blood vessels)
• Subcutaneous fibrosis (thickening of tissue)
• Hair loss

Rarely, complications can occur which may include:

• Lymphoedema – the swelling of bodily tissues, although the risk of this happening is lower than for other cancer types and the VMAT technique reduces this risk further
• Second cancer – while there is a theoretical risk of developing a cancer in the skin around the treated area, the risk is very small. Your consultant will be available to answer any of your concerns
• Non-healing ulcer
• Permanent bone or cartilage damage
• Cataracts

External beam radiotherapy doesn’t make you radioactive. It’s perfectly safe for you to be with other people, including children and pregnant women, throughout your treatment.

We advise that you eat a normal, healthy, balanced diet during your treatment and drink more fluids than normal to keep you hydrated.

Wherever possible, wear loose fitting clothing made of natural fibres such as cotton or silk over the treatment area. This will help to reduce irritation.

You’ll be able to swim during the early stages of your treatment but you should wash your skin well after swimming. If your skin starts to have a reaction, you should talk to your radiotherapy team. We advise you not to swim for extensive periods and avoid taking long baths to help protect your skin which may become red, darker or discoloured if you have brown or black skin, or sore during treatment.

Over the course of your treatment, you may find that your skin becomes red if you have white skin, darker or discoloured if you have brown or black skin, sore and itchy. It may even break in some areas.

Your treatment team will be checking your skin each day and you’ll have a more in-depth assessment with your care team once or more a week if required. By following the care advice provided, you can help prevent skin reactions from worsening.

Depending on your treatment site, you may have a gap during your treatment to allow your skin to recover.

After your treatment course, it should take around two to four weeks for the redness, discolouration and soreness to heal.

Although more uncommon, long-term side effects can occur as a side effect of radiotherapy to the skin. These include:

• Permanent skin changes (texture and colour - including redness if you have white skin, darkening or discolouration of the skin if you have brown or black skin)
• Telangiectasia (formation of small but prominent blood vessels)
• Subcutaneous fibrosis (thickening of tissue)
• Hair loss

Avoid exposing the area receiving radiotherapy to the sun during treatment and until all skin reactions have gone. Please don’t use any sun protection cream during your radiotherapy treatment. Instead, it’s better to protect your skin by staying in the shade and covering up with appropriate clothing and headwear. Your skin in and around the area that has been treated will always be more sensitive to the sun.

Once your treatment has finished and the side effects have settled, you should always protect the treated area by using at least SPF 50 sun cream.