Prognostic significance of standardized uptake value and metabolic tumour volume on ¹⁸F-FDG PET/CT in oropharyngeal squamous cell carcinoma.

Abstract

Standardized uptake value (SUV) and metabolic tumour volume (MTV) measured by (18)F-FDG PET/CT are emerging prognostic biomarkers in human solid cancers. However, their prognostic significance in oropharyngeal squamous cell carcinoma (OPSCC) has been investigated in only a few studies and with small cohorts. In the present study we evaluated the ability of SUV, MTV, and total lesion glycolysis (TLG) measured on pretreatment (18)F-FDG PET/CT to predict recurrence and survival outcomes in OPSCC. The study included 221 patients with OPSCC who underwent pretreatment (18)F-FDG PET/CT imaging and received definitive treatment at our tertiary referral centre. The PET imaging parameters SUVmax, SUVpeak, MTV and TLG were measured in primary tumours with focal (18)F-FDG uptake. Clinical and imaging variables significantly associated with overall survival (OS) and disease-free survival (DFS) were identified by univariate and multivariate analyses using the Cox proportional hazards model. Overall 5-year OS and DFS rates were 72.0 % and 79.5 %, respectively, during a median follow-up of 61 months (range 18 - 122 months). The cut-off values of tumour SUVmax, SUVpeak, MTV and TLG for prediction of DFS were 7.55, 6.80, 11.06 mL and 78.56 g, respectively. Univariate analyses showed that age >60 years, advanced tumour stage, and high tumour SUVmax, SUVpeak, MTV and TLG were significantly associated with decreased OS and DFS (P < 0.05 each). Age, tumour SUVmax and MTV remained independent variables for OS and DFS (P < 0.05 each) in the multivariate analyses. SUVmax and MTV measured on pretreatment (18)F-FDG PET/CT may be useful in predicting the clinical outcomes in OPSCC patients. This study investigated the clinical prognostic value of imaging parameters from pretreatment (18)F-FDG PET/CT in 221 patients who underwent definitive treatment for oropharyngeal squamous cell carcinoma. High maximum standardized uptake value and metabolic tumour volume were independently associated with decreased disease-free and overall survival outcomes.