2011 Volume 62 Issue 1 Pages 11-16
FDG-PET is employed to decide the treatment strategy for malignant tumors clinically. Meanwhile, glucose metabolism is enhanced in the exercise of muscles. Because vocal folds always conduct glucose metabolism by phonation and swallowing, physiological accumulation of FDG may be found in the normal larynx. In this study we examined FDG accumulation in the larynx of patients with unilateral vocal fold paralysis established by endoscope. FDG-PET/CT was taken one hour after the FDG administration (early image) and again two hours later (delayed image). All patients had no chance to utter after the FDG administration. In 25 of the 28 patients with unilateral vocal fold paralysis, SUVmax was higher, by visual inspection, in the normal side of the larynx than in the paralyzed side. None of the 3 patients in whom no accumulation was seen on the non-paralyzed side had malignant disease. In both images, SUVmax of the normal side was significantly higher than paralyzed side (p<0.01). In the delayed images, accumulation of FDG was significantly higher than that in the early images (p<0.01). We believe that strong FDG accumulation in the normal side of the larynx of patients with unilateral vocal fold paralysis may owe to high glucose metabolism of the vocal muscles from muscle hyperkinesis. We conclude that unilateral accumulation in the larynx suggests not only cancer of that same side of the larynx but also paralysis of the other side.
