How Doctors Detect Lung Cancer
Doctors use a variety of tests to detect and diagnose lung cancer. The specific test used for each patient depends on the location of a potential tumor or mass. The doctor may test cells, use imaging technology or analyze lung fluids.
During a lung biopsy, the doctor removes a sample of tissue from the lungs and tests it for cancer cells. In some cases, the doctor inserts a hollow needle into the lungs and pulls out a tissue sample without an incision. For patients with potentially cancerous tumors in the biggest parts of the lungs, the doctor may slide a bronchoscope down the throat and remove samples with a brush or surgical instruments. During a mediastinoscopy, the doctor makes a small cut in the neck to secure the samples from the lungs.
Fluid and Mucus Analysis
Mucus and the fluids around the lungs may contain cancerous cells. With a sputum cytology test, the doctor uses a microscope to analyze the mucus that a patient coughs up. In most cases, mucus analysis is useful for detecting small-cell and squamous-cell cancers. If a patient has fluid around the lungs, the doctor uses thoracentesis to remove the fluid with a hollow needle. The doctor analyzes the fluid with a microscope or chemical test to check for cancer cells.
Lung cancer can be detected with computing tomography or magnetic resonance imaging. A CT scanner moves around the body and uses X-rays to create a cross section, so the doctor can locate the tumor. During an MRI scan, the patient is scanned with radio waves. Doctors often use MRI scans to look for the places where a cancer has spread.
Positron Emission Tomography
If a doctor suspects that a patient is at the beginning stages of lung cancer, he may use positron emission tomography to scan the body. A PET scan often happens after a primary scan has located a suspicious tumor or mass. The patient takes fluorodeoxyglucose, a radioactive form of sugar, before the procedure. The PET scan maps the radioactive areas to give the doctor a picture of the lungs and the other areas where the cancer may have spread.
After the initial lung cancer diagnosis, the doctor may use a bone scan to determine the spread of the cancer. The doctor injects the patient with radionuclide, which spreads throughout the blood. The scanning equipment photographs the bones, and the doctor examines the images to find areas that have absorbed more of the radioactive fluid; those areas can indicate places that the cancer has metastasized.
In many cases, a doctor uses more than one test to detect and diagnose lung cancer. Depending on the patient, additional tests are necessary to determine the spread and severity of the disease.