Prognostic significance of metabolic tumour volume and maximum standard uptake value of fluor-18-fluorodeoxyglucose positron emission tomography with computed tomography in nasopharyngeal carcinoma

Abstract

Aim of the study: To evaluate the prognostic role of markers of fluor-18-fluorodeoxyglucose positron emission tomography with computed tomography ( 18 F-FDG-PET-CT), such as maximum standard uptake value (SUV max ) and metabolic tumour volume (MTV) measured at primary and nodal disease, and their clinical significance in terms of predicting treatment outcomes and survival. Material and methods: Between January 2017 and January 2020, 20 case records of nasopharyngeal carcinoma patients who underwent 18 F-FDG-PET-CT as part of staging workup before radiotherapy and as a part of response evaluation after radiotherapy were retrospectively reviewed. Results: At a median follow-up of 34.7 months, the 2-year progression-free survival (PFS) was 70% and 2-year overall survival (OS) was 79%. Patients with a lower nodal SUV max (SUV max-N ) had a better 2-year PFS (91% vs. 46%; p = 0.035) and 2-year OS (95% vs. 58%; p = 0.015). A high SUV max-N of > 10.58 was a negative predictor of OS (95% confidence interval [CI]: 0.93-1; p = 0.003) as well as PFS (95% CI: 0.64-1; p = 0.017). Also, a high MTV > 25.8 cm 3 was a negative predictor of PFS (95% CI: 0.58-0.98; p = 0.048). MTV was an independent predictor of PFS and OS on univariate analysis, whereas it was not significant in the Cox regression multivariate analysis. Conclusions: High values of MTV and SUV max-N can be considered as independent prognostic factors of OS and PFS in nasopharyngeal cancer patients treated with concurrent chemoradiation, highlighting the need for more intensified treatment.