Standard Whole Body PET/CT Misses Distant Lesions
6/29/2005 Toronto, Ontario, Canada Pippa Wysong Medscape (/www.medscape.com) The routinely used whole body (WB) positron emission tomography (PET)/computed tomography (CT) scans, also known as limited whole body (LWB), can miss more than 5% of metastatic cancer lesions, according to researchers from Saint Louis University (SLU) who presented their findings here at the Society of Nuclear Medicine 52nd Annual Meeting. Researchers suggest true whole body (TWB) scans would provide better staging and restaging. That is, scans from head to toe, as opposed to from the base of the skull to about midthigh. The term "whole body" is somewhat misleading, according to the poster, coauthored by Medhat Osman, MD, from SLU. These scans are done with the patients' arms up, and the most commonly used field of view does not cover the entire body. WB scans do not include the brain or the skull, plus it leaves out portions of the upper and lower extremities. A study was done to see whether performing TWB scans revealed additional lesions above and beyond the traditional approach. A total of 500 consecutive cancer patients underwent F-18 fluorodeoxyglucose-PET (FDG-PET)/CT scans that extended from the top of the skull to the bottom of their feet. Scans were done 60 minutes after patients received an injection of 0.14 mCi per kg of FDG. Patients in whom it was already known that malignancies were present outside of the normal LWB area were excluded from the study. The images were evaluated and newly suspected metastases outside the normal LWB areas [...]