Keypoints
Staging tests Once a diagnosis of non-Hodgkin's lymphoma has been made, it is important that the lymphoma is staged, usually into one of four stages (I-IV) (See Principles of staging). Staging provides a way of describing:
It is vital to know the stage of the lymphoma before starting treatment. It might seem that treatment is being delayed unnecessarily while staging tests are being done. However, correct treatment depends on having the correct diagnosis, and any slight delay will be more than made up for by being able to give the best treatment from the start. Because the doctors who interpret or 'read' the test results are specialists in this field and not necessarily the same doctors that see the patients and make the treatment decisions, it is usual to have to wait at least a few days before results are known. Many tests are used to stage non-Hodgkin's lymphomas, but not every patient needs to have every test. Some of the tests include:
Bone marrow is the soft tissue found in the middle of bones. It is where the blood cells of the body are made and where the majority of blood cells mature before they circulate in the bloodstream. A bone marrow biopsy involves taking a sample of bone marrow for testing, which can be performed with a local anaesthetic. The sample is usually taken from the upper part of the hip bones in the lower back or, rarely, from the breast bone. The biopsy itself is a simple procedure in which two samples of tissue are taken using separate needles. In the first, a fine needle aspiration of the fluid and cells surrounding the bone marrow is taken, usually from the hip, but occasionally from the breast bone. In the second, another needle is used to remove a small part of the bone marrow itself, almost always from the hip. This can be painful, and patients may be advised by their doctor or nurse to take painkillers before the local anaesthetic starts to wear off. Sometimes, there is some pain or discomfort for a day or two after the biopsy, and painkillers may be needed during this time as well. The bone marrow that has been sampled during the biopsy is examined under a microscope. In this way, it is possible to tell whether there are lymphoma cells in the bone marrow. 
Most X-rays involve no preparation at all and are very quick, taking only a few minutes. Radiation is passed through the body and an image is obtained. This image shows the bones, but it also gives information about the soft tissues of the body. For example, a chest X-ray can show if lymphoma has spread to the lungs or to the lymph nodes in the chest. A CT scan uses X-rays and produces X-ray-like pictures. However, it produces a number of images taken at different 'layers' of the body, so building up, in effect, a three-dimensional picture. Like an X-ray, it can show whether the lymphoma is involving lymph nodes and other organs of the body. The scan is not painful or difficult, but it takes longer than an X-ray (up to half an hour or so). For some scans, it is necessary to avoid eating or drinking for a few hours before the scan. Some scans involve an injection of a dye-like substance that shows up on the scans. The person being scanned must pass through a scanner and lie still inside the scanner for the duration of the scan.
An MRI scan, like a CT scan, produces images taken at different 'layers' of the body, but uses magnetic fields to produce the images. The scan can take up to an hour or so, and the person being scanned must lie still for the duration of the scan. The scan is painless, but the scanning machine is noisy, so earplugs are supplied. Because the scanner is a very powerful magnet, all metal (such as jewellery and watches) must be removed. MRI scans are not suitable for people who have had metal implants (such as a heart monitor, a joint replacement, a joint pin or plate, or surgical clips). Some people find being inside the scanner claustrophobic. It is often helpful to mention this before the scan starts, since extra support can be provided. An ultrasound scan produces images by using sound waves, which bounce off the various tissues and organs inside the body to produce echoes. The echoes are converted into images by a computer. Before the scan is done, gel is spread on the part of the body to be scanned. Then, a small handheld device that emits sound waves is passed over the relevant area while the person being scanned lies still. The test is painless and takes only a few minutes. A PET, or positron emission tomography, scan is a highly sensitive technique that uses X-rays to detect particles given out by substances that have been injected into the body. This allows doctors to tell apart 'active' lymphoma cells, which are capable of causing disease, and inactive lumps of cells. Therefore, the technique is useful after treatment for non-Hodgkin's lymphoma to see how successful it has been. As it involves expensive equipment, PET scanning is currently not available everywhere. A lumbar puncture is a way of telling whether the non-Hodgkin's lymphoma is involving the central nervous system. It is simple procedure that takes only a few minutes. It involves a needle being inserted through the skin of the lower back and into the fluid that surrounds the spinal cord. A small amount of this fluid is drawn out so that it can be examined under a microscope for lymphoma cells. A local anaesthetic is sometimes given, and the patient has to lie on his or her side during the procedure. Afterwards, the patient has to lie flat for an hour or two. This reduces the chances of getting a headache, which is common after a lumbar puncture. If a headache does occur, painkillers may be needed for a day or two after the procedure. |
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Diagnostic visits and check-ups
