18F-FDG PET/CT-Based Prognostic Survival Model After Surgery for Head and Neck Cancer

Abstract

The aims of this multicenter study were to identify clinical and preoperative PET/CT parameters predicting overall survival (OS) and distant metastasis-free survival (DMFS) in a cohort of head and neck squamous cell carcinoma patients treated with surgery, to generate a prognostic model of OS and DMFS, and to validate this prognostic model with an independent cohort. Methods: A total of 382 consecutive patients with head and neck squamous cell carcinoma, divided into training (n = 318) and validation (n = 64) cohorts, were retrospectively included. The following PET/CT parameters were analyzed: clinical parameters, SUV_max, SUV_mean, metabolic tumor volume (MTV), total lesion glycolysis, and distance parameters for the primary tumor and lymph nodes defined by 2 segmentation methods (relative SUV_max threshold and absolute SUV threshold). Cox analyses were performed for OS and DMFS in the training cohort. The concordance index (c-index) was used to identify highly prognostic parameters. These prognostic parameters were externally tested in the validation cohort. Results: In multivariable analysis, the significant parameters for OS were T stage and nodal MTV, with a c-index of 0.64 (P < 0.001). For DMFS, the significant parameters were T stage, nodal MTV, and maximal tumor-node distance, with a c-index of 0.76 (P < 0.001). These combinations of parameters were externally validated, with c-indices of 0.63 (P < 0.001) and 0.71 (P < 0.001) for OS and DMFS, respectively. Conclusion: The nodal MTV associated with the maximal tumor-node distance was significantly correlated with the risk of DMFS. Moreover, this parameter, in addition to clinical parameters, was associated with a higher risk of death. These prognostic factors may be used to tailor individualized treatment.

Keywords: PET/CT; distant metastasis; head and neck cancer; overall survival; prognosis.

Graphical abstract

FIGURE 1.

Flowchart. CUP = carcinoma of unknown primary.

FIGURE 2.

Parameters significantly affecting OS in training cohort in multivariable analysis (number of deaths = 116; c-index = 0.64).

FIGURE 3.

Nomogram for predicting OS at 24 mo. For each PET parameter, corresponding points were obtained by drawing line upward from corresponding values to “Points” line. Total points for each patient were obtained by summing points for each individual factor in nomogram and were plotted on “Total points” line. Line was drawn downward to read corresponding predictions of 24-mo OS.

FIGURE 4.

Parameters significantly affecting DMFS in training cohort in multivariable analysis (number of patients with distant metastasis = 51; c-index = 0.76).

FIGURE 5.

Nomogram for predicting DMFS at 24 mo.