Читать книгу Cancer is a Word, Not a Sentence - Miriam Stoppard - Страница 16

There are so many types of tests that it would be impossible to cover all of them here. But there follows a brief guide to some of the main tests, what they involve, and how they help. Blood tests are done for so many different reasons that they are covered in a separate table on page 226.

X-rays. Chest x-rays show the lungs, size of the heart, ribs, and (to some extent) the spine. They are usually taken with you standing up straight on and then sideways. They can show many different abnormalities of the lung or of fluid outside the lung (pleural effusion), enlargement of the heart or fluid around the heart, abnormalities in the ribs and sometimes in the spine.

Bone x-rays, of course, show fractures. They can also show areas of cancer if the cancer is either dissolving the bone (lytic) or making excess bone (sclerotic). They are important in trying to decide if there is a risk of fracture. Bone x-rays can be uncomfortable but usually only last a short while.

Mammograms are x-rays of the breast tissue and are uncomfortable as the breast tissue is compressed between glass plates. Mammograms may be abnormal in many benign conditions, and occasionally some cancers are not visible to x-rays.

A barium enema consists of x-rays done after the colon has been filled with a liquid that shows up on x-rays.

Scans. A bone scan (see page 35 for a description) is a reliable indicator of metastases in some cancers, such as breast, but not all.

An ultrasound uses very high frequency sound waves to examine internal organs. This is useful in detecting abnormalities inside the liver, the lymph nodes in the abdomen, the uterus and ovaries and many other structures in the abdomen or pelvis.

A CT scan uses sophisticated computer analysis of ‘slices’ of x-rays taken up and down the body. It is a standard way of assessing many parts of the body.

An MRI scan detects changes in the magnetic fields in your body after short surges of magnetic fields are applied. This technique is good at detecting water-containing tissues and is particularly effective in the brain and spinal cord, areas where CT scans are not always so useful.

A gallium scan is similar to a bone scan but injects gallium, an isotope which is taken up by certain cells in the lymphoid group. This makes it helpful in assessing Hodgkin’s disease and some lymphomas.

A PET scan is not routine, but can be useful in conjunction with CT scan results to image tumours.

Tests used to look directly at a tumour or organ. These involve a small tube being passed into a specific area of the body to examine it in detail. A strong sedative or a general anaesthetic is often used to minimise any discomfort.

A colonoscopy is used in screening and in diagnosis for tumours (cancers and polyps) of the colon and rectum. A bronchoscopy is one method of assessing cancers of the lung and airways. A laryngoscopy is used to assess cancers of the throat, larynx, mouth or nasal passages, as well as to monitor effects of treatment.

A gastroscopy or endoscopy is used to assess abnormalities in the oesophagus and stomach. A cytoscopy assesses tumours of the bladder, and can be a method of treating many of them. A laparoscopy is used to view the abdomen and pelvis and often to take biopsies. It is used to assess many cancers, including canver of the ovary. A mediastinoscopy looks at the middle of the chest (between the lungs) and is important in staging lung cancer and some other tumours.

Other routine tests. An ECG is a routine recording of the electrical activity of the heart. It is often done as a baseline assessment before treatment starts (particularly if treatment might affect the heart). An EEG records the electrical activity of the brain and is sometimes used if there are episodes of loss of consciousness that might be seizures. A MUGA measures the percentage of blood in the heart that is ejected with each heartbeat (which roughly equals the strength of the heartbeat). A few chemotherapy drugs can weaken the strength of the heartbeat and this test can detect that early; a baseline MUGA is often done to measure the strength of the heartbeat before treatment starts.

This brings us round to the question, ‘Do I really have to have these tests?’ The answer is that having any tests is not compulsory. Nobody’s giving you an order. But in each type of cancer there is a group of tests that have a fair chance of detecting any unexpected problems. If your particular cancer has a moderate or higher chance of spreading, the fact that your doctor is suggesting you have a series of tests of, say, your bones and liver and lungs, does not mean that she expects to find problems there. It means that she wishes to prove conclusively that there are no problems there. So, those irritating tests are a sign that your treatment plan is based on sound factual knowledge.

STEP THREE

‘Why do I need more than one type of treatment?’

Treatment types and what they do

This is going to be a very brief introduction to the principles of the four main types of cancer treatment—surgery, radiotherapy (radiation oncology), chemotherapy, and biological therapy (including hormone therapy).

In this bird’s-eye view I’m going to explain in a couple of paragraphs how each of the four types of treatment works. You may find that you know this already but quite often it’s easy to be confused about, say, radiotherapy, so Step Three will just set the scene for you.

In Part Two I set out in greater detail what’s actually involved in the different types of treatment, plus some of the specific actions and side effects.