PET can help physicians effectively pinpoint the source of cancer. This is possible because many cancer cells are highly metabolic and therefore synthesize the radioactive glucose (sugar) that is injected in the patient prior to the exam. The areas of high glucose uptake are dramatically displayed in the scan imagery, as opposed to the anatomical imagery of CT or MRI, which cannot detect active, viable tumors.
If cancer is found early, it can often be cured. A PET scan can be used in early diagnosis, assisting physicians in determining the best method for treatment. A whole body PET scan may detect whether cancer is isolated to one specific area or has spread to other organs before a treatment path is determined.
In the United States in 2009 alone, society epidemiologists predict that there will be 1,479,350 new cancer cases (766,130 in men and 713,220 in women). They estimate that this will result in 562,340 cancer deaths (292,540 in men and 269,800 in women).
What is Cancer?
Cancer comes in a variety of forms. Basically, cancer occurs when cells in the body begin to grow chaotically. Normally, cells grow, divide, and produce more cells to keep the body healthy and functioning properly. Sometimes, however, the process goes astray; cells keep dividing when new cells are not needed. Some types of cells are more prone to abnormal growth than others. The mass of extra cells forms a growth or tumor, which can be benign or malignant.
Benign tumors are not cancer. They often can be removed and, in most cases, they do not come back. Cells in benign tumors do not spread to other parts of the body. More importantly, benign tumors are rarely life threatening.
Malignant tumors are cancer. Cells in malignant tumors are abnormal and divide without control or order. These cancer cells can invade and destroy the tissue around them. In a process called metastasis, cancerous cells break away from the organs on which they are growing and travel to other parts of the body, where they continue to grow. Cells from cancerous ovaries, for example, commonly spread to the abdomen and nearby internal organs. Eventually, they can invade the bloodstream and lymph system (the two systems of vessels that bathe and feed all of the body’s organs) and travel to organs throughout the body. Metastasis is how cancer “colonizes” to produce new tumors within the body.