Positron-emission tomography enhancement after vocal fold injection medialization.

Abstract

The potential for the misinterpretation of positron-emission tomography (PET) scans in the context of a possible malignancy has been confirmed in a case report showing increased 18F-fluorodeoxyglucose (FDG) uptake after unilateral vocal fold augmentation medialization. We sought to expand these findings by investigating FDG uptake in a larger cohort of patients via a retrospective chart review. We examined the records of 15 adults-8 men and 7 women-who had undergone vocal fold augmentation for unilateral vocal fold paralysis and at least one subsequent PET scan. The differences in PET standard uptake value (SUV) between the injected and noninjected vocal folds were assessed via the Wilcoxon signed-rank test. A Spearman rank correlation coefficient was then used to estimate the relationship between differences in PET uptake and the length of time between the injection and the follow-up PET scan. The mean SUV of the injected vocal folds was 3.70, and the mean in the noninjected folds was 2.97. The difference did not achieve statistical significance (p = 0.34). In addition, the rank correlation coefficient with regard to the association between the difference in PET uptake and the duration between injection and PET was -0.24, suggesting an inverse relationship. However, the correlation coefficient did not differ significantly from zero (p = 0.34). We conclude that PET uptake after vocal fold augmentation medialization is variable and that it can increase substantially. This information should be considered in the context of the diagnostic accuracy of malignancy on PET.