Lung Cancer - PET and CT
Lung cancer is one of the leading causes of cancer deaths in the US, accounting for nearly 36% of all lethal cancers. Approximately 178,000 new cases are diagnosed each year with approximately 169,400 deaths.
Lung cancer is such a deadly disease because it can grow for a long time before any signs of it may appear. Often times it spreads before it is found, metastasizing to other parts of the body.
Lung masses have traditionally been evaluated through the use of planar chest x-rays, CT and MRI scanning. These tests can provide information regarding the size and location of the lung mass but they often cannot tell if the abnormality is benign or malignant. For this, the patient may need to undergo a biopsy. Not all patients are good candidates for biopsy due to the state of their health or the location of the mass.
Most patients are between 55 to 65 years old when they are diagnosed. Unfortunately, the overall 5 year survival rate in patients with the different types of lung cancer is less than 10%. However, That five-year survival rate can increase to 35-40% when lung cancer is found early enough for surgery to remove it before it has the opportunity to metastasize.
Lung cancer may take many years to develop - it is a silent killer because it can grow for a long time before it is found. Once the lung cancer occurs, cancer cells can break away and spread to other parts of the body (metastasis). Lung cancer is such a deadly disease because it often spreads before it is found.
There are many types of lung cancer, but most belong to one of two types:
Small-cell lung cancer (SCLC): Although the cancer cells are small, they spread quickly to form large tumors that then can progress to other parts of the body, including lymph nodes, brain, liver, and bones. PET is not used for this disease because imaging the location of the cancer does not change the treatment.
Non-small cell lung cancer (NSCLC): NSCLC, which is the most common type of lung cancer, includes several different sub-types: Squamous cell, adenocarcinoma, and large cell. These types too may spread quickly to other parts of the body. PET is very useful for this type of lung cancer.
Although most lung cancers do not cause symptoms until they have spread, some of the most common early symptoms include the following:
A cough that does not go away
Bloody or reddish colored mucous that is coughed up
Shortness of breath or wheezing
Rapid loss of weight or unexpected loss of appetite
Since most people with early lung cancer do not have any symptoms, only about 15 percent of lung cancers are found in the early stages. When lung cancer is found early, it is often because a chest x-ray, CT scan, or other test was being done for another reason.
How Does PET Make a Difference?
Solitary pulmonary nodules can be screened with high accuracy using PET. Conversely, CT and MRI cannot tell the difference between benign and malignant tumors. Moreover, PET is non-invasive and thus not associated with any morbidity as compared to lung biopsy.
PET can determine the extent of the disease at initial diagnosis. PET is more accurate than CT in determining tumor stage and provides a cost-effective tool for differentiating operable from inoperable disease.
PET is effective in ascertaining lung tumor response to therapy and in detecting recurrence in successfully treated lesions. PET results are the most reliable indicators of patient survival.
Following are some useful resources if you wish to find out more about lung cancer:
For more information about the PET/CT scanner or to make an appointment, please call the Division of Nuclear Medicine at (410) 328-6891.