What’s involved in high dose treatment?

Before a transplant, high-dose treatment is given to try to destroy any remaining cancer cells. This is called conditioning treatment. You usually stay in hospital to have the treatment. You will be given advice about what to bring to make your stay more comfortable.

A combination of chemotherapy drugs will be given to you through your PICC or central line. Some people also receive radiotherapy to the whole body (total body irradiation). One or two days after you finish high-dose treatment, a nurse will give you your collected stem cells through your central or PICC line. The stem cells travel through your blood to your bone marrow, where they’ll engraft and start to make blood cells.

You will stay in hospital until your blood count increases. This can take 2-3 weeks. Until then, you will be at high risk of infection and side effects. But you’ll be closely monitored with a daily routine of care and checks.

Once your blood count begins to rise, your healthcare team will plan for you to return home.

High-dose treatment

High-dose treatment, also called conditioning treatment, is given to destroy as many cancer cells as possible that remain in your body.

The treatment involves high doses of chemotherapy. Some people also have radiotherapy to the whole body. This is called total body irradiation, or TBI.

Going into hospital

You usually stay in hospital to have the treatment. Although it may only last one or a few days, from this point you will probably be in hospital for a few weeks. This is because after the treatment you need to wait for your blood count to recover. This can take 2–3 weeks.

In some hospitals, you have high-dose treatment as a day patient and stay in accommodation nearby, which the hospital arranges for you. When your blood counts become low, you will be admitted to the hospital.


Chemotherapy is the use of anti-cancer drugs to destroy cancer cells. You’ll probably already have had some chemotherapy as part of your original treatment, so you may have some idea of what to expect.

The chemotherapy is given through your central line, PICC line or implantable port , along with plenty of fluids. The treatment is usually given over several days and often involves a combination of chemotherapy drugs.

We have more information on the side effects of chemotherapy.


Radiotherapy uses high-energy rays to destroy cancer cells. You may be given total body irradiation (TBI) as conditioning treatment before your transplant.

TBI may be given twice a day for 6–8 sessions over 3–4 days.

If you’re having radiotherapy, you will go to the radiotherapy department for a planning session a few days before the treatment begins. The doctor will explain what will happen during your radiotherapy, and you can ask any questions you may have.

Before each session, the radiographer will position you carefully and will make sure you’re comfortable. You’ll have to change position a few times during the session. The radiographer will explain this to you.

During the treatment, you’ll be left alone in the room, but you’ll be able to talk to the radiographer, who will be watching you from the next room. Each session lasts about 40 minutes, but the radiotherapy only takes about 10–20 minutes. You can bring some CDs to listen to during your treatment.

Radiotherapy isn’t painful, but you do have to keep still while your treatment is being given.

Many people find that they don’t have many side effects from total body irradiation. This is because the treatment gives a relatively low dose of radiation to all parts of the body. Possible side effects include tiredness, feeling sick (nausea), diarrhoea and a sore mouth.

Having the stem cells

Your stem cells will be given back to you by infusion (drip) through your central line, PICC line or implantable port. This will be 1–2 days after the high-dose treatment has finished. This is similar to having a blood transfusion.

You’ll be closely monitored during the infusion. Some people have mild side effects during the infusion, such as breathlessness or feeling sick (nausea). Rarely, a severe allergic reaction can happen. You will be given medicine before the infusion to help prevent or reduce any reaction.

You and your visitors might notice a strong smell similar to sweetcorn for a few days after the infusion. This is from the preservative that’s used to protect the stem cells during storage.

Waiting for your blood count to recover (Engraftment)

Once you’ve had the infusion, the stem cells travel to your bone marrow, where they begin to make blood cells – this is called engraftment. It can take two or more weeks before some of the new blood cells are released into the bloodstream. During this time you have a high risk of infection and other problems such as bleeding and anaemia. You may also begin to feel some other side effects.

You will have low numbers of red blood cells, white blood cells and platelets in your blood for some time. This can cause side effects. You’ll have blood samples taken every day to check your blood count.

You may be given growth factors by injection to stimulate your bone marrow to produce new white blood cells more quickly. Using growth factors can reduce the length of time you’re at risk from some of side effects.

You will usually stay in a single room to help protect you from the risk of infection. You may think that you’ll have a lot of time on your hands, but a daily routine of care and checks will occupy much of your time.

This will include having:

  • blood taken from your central line
  • medicines given into your central line
  • your ‘drip’ (intravenous infusion) changed when needed
  • your temperature, pulse and blood pressure taken
  • your tummy and mouth examined
  • your central line checked.

Once the number of blood cells (blood count) begins to rise, your medical team will start to plan for you to go home.

Back to Being treated with high-dose treatment with stem cell support

Collecting stem cells

Your stems cells will be collected and stored before you have high-dose treatment.