Combined positron emission tomography (PET) and computed tomography (CT) imaging of lymphoma patients is a more effective method to evaluate response to radiation therapy, and may help patients avoid unnecessary follow-up treatments, a study by researchers at the University of Southern California (USC) suggests.
The findings of the study will be published in the March issue of the journal Radiology, and is now available online.
The clinical study is the first to show the advantage of combined PET-CT imaging in evaluating radioimmunotherapy for patients with non-Hodgkin lymphoma, says Gary Ulaner, M.D., Ph.D., radiology resident and nuclear medicine fellow at the Keck School of Medicine of USC and the principal investigator of the study.
"Combined PET-CT imaging is more accurate in defining a complete response to radio-immunotherapy treatment," Ulaner says. "Specifically, PET-CT is able to correctly label inactive scar masses, which are sometimes mistaken for active cancer when CT is used alone."
Radioimmunotherapy is a type of radiation treatment that targets cancer cells through antibodies. The therapy causes less harm to healthy cells and usually results in fewer side effects than other cancer treatments, Ulaner notes. Typically, the treatment has been evaluated by use of CT imaging alone, which uses special x-ray equipment to produce multiple images of the inside of the body.
PET is a type of nuclear medicine imaging that uses very small amounts of radioactive material to diagnose or treat disease and other abnormalities. When PET and CT scans are combined they can produce a more complete image of the cancer metabolism, he says.