PET/CT systems provide images of functional processes and anatomy in a single evaluation, which could make the procedure especially beneficial to children — for whom having fewer tests helps avoid added emotional strain.

Because there is little research on how PET/CT compares with conventional imaging examinations in pediatric patients, Dr. Richard L. Wahl, Dr. Mitsuaki Tatsumi and Dr. John H. Miller, all from the department of radiology at Johns Hopkins Medical Institutions in Baltimore, evaluated the diagnostic performance of the procedure in children between 3 and 19 years old with noncentral nervous system malignancies.

Fifty-five patients received 151 examinations with a combined PET/CT scanner from GE Healthcare. Of these examinations, 108 also were accompanied by a conventional imaging procedure, such as contrast CT or MRI, within one month of the PET/CT test. Two radiologists reviewed and compared the images from all of the examinations and recorded any abnormalities that could relate to malignant lesions.

As detailed in the December issue of The Journal of Nuclear Medicine, they found that 56 cases were positive (malignant) in both the PET/CT scans and the conventional imaging exams. Fifty-four of these were confirmed as true-positive, according to a reference standard. They also found that PET/CT detected 26 malignancies that the conventional imaging procedures did not, 20 of which were confirmed as true-positive. And the conventional method detected 54 lesions that PET/CT did not; however, 52 of these were falsely detected.

Overall, the researchers discovered that PET/CT performed better than the conventional imaging methods and accurately detected 90 percent of the lesions. They believe their results indicate that PET/CT is a promising diagnostic test for evaluating pediatric malignancies.