PET Scans Can Spot Cervical Cancer's Return

TUESDAY, Nov. 20 (HealthDay News) -- Whole-body positron emission tomography (PET) scans three months after cervical cancer patients have completed therapy can help determine whether they're cancer-free or require further treatment, U.S. researchers say.

It can be difficult to determine if treatment has eliminated cervical tumors, noted study author Dr. Julie K. Schwarz, a Barnes-Jewish Hospital resident in the department of radiation oncology at Washington University School of Medicine, St. Louis. Small tumors are difficult to detect with pelvic exams and obvious symptoms such as leg swelling don't occur until tumors are quite large.

CT and MRI scans aren't able to differentiate between tumor tissue and surrounding tissue, the expert added. There's also no blood test to indicate the presence of cervical cancer, and Pap tests can be inaccurate because of tissue changes caused by radiation therapy.

However, Schwarz and her colleagues found that cervical tumors glow brightly in FDG-PET scans, which detect emissions from radioactively tagged blood sugar (glucose). Tumor tissue traps more of this glucose than normal tissue.

"This is the first time we can say that we have a reliable test to follow cervical cancer patients after therapy," Schwarz said in a prepared statement. "We ask them to come back for a follow-up visit about three months after treatment is finished, and we perform a PET scan. If the scan shows a complete response to treatment, we can say with confidence that they are doing to do extremely well."

If the PET scan reveals cervical tumors that haven't responded to treatment, patients can discuss further treatment options with their doctor.

The study was published in the Nov. 21 issue of the Journal of the American Medical Association.

More information

The U.S. National Women's Health Information Center has more about cervical cancer.

SOURCE: Washington University, St. Louis, news release, Nov. 20, 2007