Scanner tracks cervical cancer
ST. LOUIS — A machine invented at Washington University to reveal the inner workings of brains and hearts is emerging as a premier tool for tracking cervical cancer.
The device, called a positron emission tomography scanner, is similar to MRI scanners but uses radioactivity instead of X-rays to create images of blood flowing through organs, brain activity and other processes.
New research from the Siteman Cancer Center at Barnes-Jewish Hospital and Washington University show that PET scans are more accurate than any other method at predicting the aggressiveness of a cervical cancer tumor. The device also effectively shows whether treatments destroyed the cancer.
Previously, doctors had no way to determine if therapies were working until a patient experienced symptoms or another tumor was found.
"The look on (patients') faces, the happiness and the joy when you tell them, 'It looks like you're going to do really well.' That's really powerful," said Dr. Julie K. Schwarz, a Barnes-Jewish Hospital resident in the Department of Radiation Oncology.
Schwarz was the lead author on one of the PET studies that was published in the Journal of the American Medical Association. Her research team studied women who had PET scans three months after completing radiation and chemotherapy between 2003 and 2006. The scans provided a more reliable measure of whether the cancer would recur, and, just as importantly, revealed whether the cancer was already beginning to return.
Each year, more than 10,000 women develop cervical cancer in the United States, and about 3,900 die of the disease.
A key to turning PET scans into cancer-fighting tools was figuring out how to turn one property of cancer cells — their need for sugar to fuel growth — against them.
The radiologists use the cancer's sugar-craving by tagging sugar molecules with radioactivity. Once the radioactive material is injected into the body, cancer cells gobble up the sugar molecules. The sugar gets trapped inside the tumor cells, which appear as bright spots on the scans.
Now, researchers are trying to find out if the scans can do more than identify cancer cells quickly.
PET scans aren't used yet for every cancer patient, but they are proving to be effective at helping doctors decide whether to continue treatment.
In some studies, researchers treated cancer patients with chemotherapy drugs, and within days, they were able to use PET scans to see whether the drug is working or a different type of treatment was needed.
