And occasionally other medical conditions give rise to similar results, making it difficult to decide what is and is not cancer. Doctors are trained to piece together information from different tests and examinations along with symptoms and medical history, and put all this information in context. For this reason, it is often best for the doctor to discuss test results with you personally. Your doctor will also advise you about which tests are necessary and how often you should have them. Usually only those tests are used which give the most helpful information about your condition.
Unnecessary tests can waste time and delay treatment.
However, if you are worried about whether you are having the right tests, talk this over with your doctor. A sample of your blood is taken to check the number of cells in your blood and to see how well your kidneys and liver are functioning. This is taken to check that your lungs and heart are healthy. CT scans use a small amount of radiation, which will be very unlikely to harm you and cannot harm anyone you come into contact with. Before the scan you will be asked to drink a special liquid which shows up on x-ray.