Lung Cancer and PET/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.
Diagnosis
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
- Chest pain
- Hoarseness
- 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:
Academy of Molecular Imaging's World of PET
American Cancer Society
Alliance for Lung Cancer Advocacy, Support, and Education (ALCASE)
American Lung Association
Cancer Links USA
International Association for the Study of Lung Cancer
Medline Plus: Lung Cancer
National Cancer Institute
|
