Further tests for non-Hodgkin lymphoma

Sometimes further tests are needed to find out whether the cancer has spread. This is called staging.

Below we describe tests that are commonly used to help stage non-Hodgkin lymphoma. You may not need to have all these tests – most people will have blood tests and some imaging tests. Some tests may be repeated during or after treatment to check your health and how well the treatment is working.

Learn more about:

• Blood tests
• Imaging tests
• Bone marrow biopsy
• Lumbar puncture (spinal tap)

Blood tests

Your doctor will take a blood sample to see how well your kidneys and liver are working, and to check the number of blood cells (blood count).

Low blood counts before treatment may suggest that the cancer has spread to the bone marrow. You will also have regular blood tests to check the effects of treatment on your total number of red blood cells, white blood cells and platelets.

Imaging tests

You will usually have at least one of the tests described below:

Chest x-ray

Before an excision biopsy, you may have an x-ray of the chest area to see if the lymphoma has spread to the lymph nodes in your chest or lungs. An x-ray is painless and takes only a few minutes.

PET-CT scan

This specialised test combines a positron emission tomography (PET) scan with a non-contrast CT scan (see opposite page) to produce a three-dimensional colour image.

For the PET scan, you will be injected with a glucose (sugar) solution containing a small amount of radioactive material. Many cancer cells show up brighter on the scan because they take up more glucose solution than normal cells do.

You will be asked to sit quietly for 30–90 minutes while the glucose moves around your body, then the PET scan itself will take about 30 minutes. Clinic staff will tell you how to prepare for the scan, particularly if you have diabetes. You will be encouraged to drink plenty of water to help the glucose solution leave your body.

The CT scan (see below) is used to help work out the precise location of any areas of concern shown on the PET scan.

CT scan

A CT (computerised tomography) scan uses x-ray beams to create a detailed three-dimensional picture of an area inside the body. Your chest, abdomen and pelvis will be scanned to check whether the cancer has spread.

Before the scan, you may be asked to drink a liquid or have a special dye called contrast injected into a vein. This helps ensure that anything unusual can be seen more clearly. The dye may make you feel hot all over and leave a strange taste in your mouth for a few minutes.

The CT scanner is large and round like a doughnut. You will lie on a table that moves in and out of the scanner. The scan is painless. While it can take 30–45 minutes to prepare for the scan, the scan itself takes only a few minutes. Most people can go home as soon as the scan is over.

Ultrasound

An ultrasound uses soundwaves to create a picture of the internal organs. This test is most commonly used to guide the needle to the correct lymph node during a core biopsy.

An ultrasound is painless and takes only a few minutes.

MRI scan

MRI (magnetic resonance imaging) scans are not commonly used for people with non-Hodgkin lymphoma, but may be used to check the brain and spinal cord.

The MRI scan uses a combination of a powerful magnet and radio waves to create detailed pictures of areas inside the body. You will lie on a treatment table that slides into a metal cylinder. The test is painless, but some people find lying in the cylinder noisy and confined. An MRI scan takes 30–60 minutes.

Bone marrow biopsy

You may need to have a bone marrow biopsy to check whether lymphoma cells have spread to the bone marrow.

A bone marrow biopsy is done in two steps:

Bone marrow aspiration – The doctor inserts a needle into the bone at the back of your hip (pelvic bone) to remove a small sample of fluid (aspirate) from the bone marrow.

Bone marrow trephine – A second needle is used to take a matchstick-wide sample of both bone and bone marrow tissue.

A bone marrow biopsy takes about 30 minutes. It is usually done as an outpatient procedure and you do not need to stay in hospital overnight. You will lie still while a local anaesthetic is injected into your pelvis (hip) to numb the area. To help you feel relaxed, you may be offered light sedation or medicine that you breathe in through an inhaler.

You may feel some pressure or discomfort during the biopsy. If you feel uncomfortable afterwards, ask a member of your health care team about pain medicine. You will need to lie flat in bed for another 30 minutes after the biopsy to make sure there is no bleeding.

The bone marrow sample is examined under a microscope to see if it contains any lymphoma cells. Results are usually available within a couple of days to a week.

Lumbar puncture (spinal tap)

A lumbar puncture is a procedure used to collect a sample of fluid that surrounds the brain and spinal cord (cerebrospinal fluid). The sample is then tested for lymphoma cells. Doctors usually diagnose non-Hodgkin lymphoma with other tests, so most people will not need to have a lumbar puncture. Sometimes a lumbar puncture may be used to deliver chemotherapy.

If you do have a lumbar puncture, you will be placed in a curled or sitting position and given a local anaesthetic. A thin needle will be inserted to remove some fluid from the space between the bones in your lower back. You may feel some discomfort. Tell your doctor if you feel any pain, as they may be able to give you some more anaesthetic.

After the procedure, you may have to lie on your back for a short time to help prevent a headache starting. If you do get a headache, it will usually get better on its own. Check with your doctor whether you can take pain medicine. A lumbar puncture can also cause nausea, but this will usually ease within a few hours.

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