Prognostic role of primary tumor metabolic-volumetric parameters of 18F-fluorodeoxyglucose positron emission tomography in tongue squamous cell carcinoma

Abstract

Aim: It was aimed to evaluate the prognostic role of primary tumor metabolic-volumetric parameters of 18F-Fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in resectable tongue squamous cell carcinoma (TSCC).
 Materials and Methods: The imaging findings of 44 TSCC patients (23 females, 21 males, mean age: 58 ± 12) with resectable tumors who underwent 18F-FDG PET/CT imaging for primary staging before surgery between 2010-2021 were evaluated retrospectively. Maximum standardized uptake value (SUVmax), total lesion glycolysis (TLG), metabolic tumor volume (MTV) of primary tumors were acquired from PET/CT. Histopathological risk factors (pathological tumor and nodal stage, perineural and lymphovascular invasion, depth of invasion, surgical margin positivity) obtained from surgical resection material of primary tumors were also recorded. The prognostic values of imaging and histopathological parameters were assessed by Cox proportional hazards regression models. Survival curves were estimated by using the Kaplan-Meier analysis.
 Results: The median follow-up period after diagnosis was 24 months (range: 2-152 months). The univariate and multivariate regression analyses demonstrated that MTV was the only parameter which was significantly related to prognosis for PFS and OS. The patients with higher MTV (> 3.13 cm3) had lower OS and PFS rates compared to those with lower MTV (≤ 3.13 cm3) (p = 0.002, p < 0.001, respectively). 
 Conclusion: Primary tumor MTV is an independent prognostic factor in resectable TSCC. PET volumetric features can be used as prognostic biomarker to predict patients with poor prognosis.