Changes in the distributions of fluorine-18-labelled fluoro-2-deoxy-d-glucose accumulation into tongue-related muscles after dissection in patients with tongue cancer.

Objectives: To elucidate the changes in the distributions of fluorine-18-labelled fluoro-2-deoxy-D-glucose (F-18-FDG) accumulation in the tongue muscles of patients following four kinds of surgical operations for tongue cancers. Methods: The changes in the distributions of F-18-FDG accumulations in the tongue muscles on positron emission tomography (PET)-CT, in association with imaging findings on CT and MRI, were retrospectively analyzed before and after four kinds of surgical operations for 50 patients with tongue cancers. Results: F-18-FDG-PET-positive areas appeared at the back of the intrinsic muscles of the tongue after invasive surgery for tongue cancers despite the absence of abnormal findings on CT and MRI. A correlation between the standardized uptake value maximum of F-18-FDG in the intrinsic muscles and the degree of invasiveness of the surgical procedures for tongue cancers (r = 0.539, p < 0.01) was found. Conclusions: It is important to pay attention to the changes in F-18-FDG distributions in the intrinsic muscles of the tongue before and after invasive surgery despite the absence of abnormal findings on CT and MRI when evaluating the tongue on F-18-FDG-PET.