Volume-based 18F-fluorodeoxyglucose positron emission tomography/computed tomography parameters correlate with delayed neck metastasis in clinical early-stage oral squamous cell carcinoma.

OBJECTIVE: There is no known preoperative marker that can effectively predict the risk of delayed neck metastasis (DNM), which is an important factor that determines the prognosis of early-stage oral cancer. In this study, we examined whether 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET)/computed tomography (CT) uptake parameters of primary cancer can predict the risk of DNM in early-stage oral squamous cell carcinoma (OSCC).

METHODS: Data from patients with stage I-II OSCC who underwent surgical resection of the primary tumor without elective neck dissection between January 2009 and December 2016 were retrospectively reviewed. Patient characteristics, histopathological factors, and PET/CT parameters (maximum standardized uptake value [SUVmax], metabolic tumor volume [MTV], and total lesion glycolysis [TLG]) were evaluated for their association with DNM. DNM rates were calculated, and the parameters that were statistically significant in the univariate analysis were used as explanatory variables. Independent factors associated with DNM were identified using multivariate analysis. For all statistical analyses, p-values < 0.05 were considered statistically significant.

RESULTS: Data from 71 patients were analyzed in the study. The overall DNM rate among all patients was 21.8%. The univariate analysis showed that the T classification, depth of invasion, pattern of invasion, lymphovascular invasion, SUVmax, MTV, and TLG were significant predictors of DNM. However, the multivariate analysis revealed that only the depth of invasion, MTV, and TLG were independent predictors of DNM.

CONCLUSION: This study suggests that, in addition to conventional predictors, volume-based PET parameters are useful predictors of DNM in those with early-stage OSCC.