HOW DO YOU FIND BONE CANCER?
Bone tumors are found through physical examination and through taking pictures (films) of the anatomic area in question. These pictures are taken and interpreted by radiologists: x-rays, CT Scan ("Cat" Scan - Computerized Tomography); MRI (Magnetic Resonance Imaging); Bone Scan (nuclear medicine) and sometimes a PET Scan (Positron Emission Tomography)
X-rays use a low dose of radiation to take pictures of the body. The bones show up well on X-rays and this is the first test you are likely to have. Sometimes X-rays can give a very characteristic picture, which can help the specialist to diagnose particular types of bone cancer. A primary bone tumor will usually show up as one of the following: destruction of bone; new bone growth; swelling over the bone and swelling in the soft tissues surrounding the bone.
This is a computerized scan using X-rays. If you have been diagnosed with a bone cancer, you will be asked to have a CT scan of your chest. This is to see if there are any signs of enlarged lymph nodes or other cancer spread. Bone cancer does sometimes spread to the lungs. You may be given an injection or a liquid to drink that is a dye called ‘contrast' before the scan. This helps to make the scan clearer to read.
Bone scans are very sensitive and can show up a number of problems with the bones. You are given a small injection of a mildly radioactive material. This collects in areas of damaged bone. These are called hot spots. Hot spots can mean bone cancer. But they can also show if you have arthritis or other bone diseases.
MRI scans are now routinely done as an investigation for bone tumors. MRI stands for magnetic resonance imaging. This is a scan using magnetism to build up a picture of the inside of the body. They are very useful for showing up how far a bone tumor has grown inside a bone. MRI scans are completely painless, but rather noisy. You cannot have an MRI if you have any metal parts in your body, for instance a pacemaker or a joint replacement.
PET stands for Positron Emission Tomography. A PET scan uses a small dosage of a chemical called radionuclide combined with a sugar. This combination is injected into patient. The radionuclide emits positrons. A PET scanner will rotate around a patient's body to detect the positron emissions given off by the radionuclide. Because malignant tumors can grow at a fast rate compared to healthy tissue, the tumor cells will use up more of the sugar which has the radionuclide attached to it. The computer then uses the measurements of glucose used to produce a picture which is color coded.Unlike anatomical imaging modalities, such as CT and MRI, PET permits assessment of chemical and physiological changes related to metabolism. This is important because functional change often predates structural changes in tissues. PET images may therefore demonstrate pathological changes long before they would be revealed by modalities like CT and MRI. However, PET is not a replacement for CT or MRI scans, but complimentary as a diagnostic tool that is used.