Independent prognostic value of whole-body metabolic tumor burden from FDG-PET in non-small cell lung cancer

Purpose

To determine whether whole-body metabolic tumor burden, measured as either metabolic tumor volume (MTV_WB) or total lesion glycolysis (TLG_WB), using FDG-PET/CT is an independent prognostic marker in non-small cell lung cancer (NSCLC).

Methods

328 patients with histologically proven NSCLC were identified for this retrospective analysis. This study was approved by our Institutional Review Board. All patients underwent baseline ¹⁸F-FDG-PET/CT scan imaging before therapy. The MTV_WB, TLG_WB, maximum standardized uptake value (SUV_maxWB) and mean standardized uptake value (SUV_meanWB) of tumors throughout the whole body were measured from FDG-PET images with semi-automated 3D contouring software.

Results

In univariate analysis, there was a statistically significant association of overall survival (OS) with the MTV_WB (hazard ratio (HR) = 1.62, p < 0.001), TLG_WB (HR = 1.47, p < 0.001). The patients with a MTV_WB ≤ median of 65.7 ml and TLG_WB ≤ median of 205.11 SUV_mean * ml had a median OS of 41.1 and 35.4 months compared with 9.5 and 9.7 months for those with a MTV_WB > 65.7 ml and TLG_WB > 205.11 SUV_mean * ml, respectively. From a series of multivariate Cox regression models, the MTV_WB and TLG_WB were significantly better than SUV_maxWB and SUV_meanWB at prognostication and significantly associated with patients’ OS with HRs of 1.50 (p < 0.001) and 1.42 (p < 0.001), respectively, after adjustment for patient’s age, gender and treatment intent as well as the tumor SUV_maxWB, histology and stage.

Conclusions

MTV_WB and TLG_WB as metabolic tumor burden measurements in ¹⁸F-FDG-PET/CT are independent prognostic markers and are significantly better than SUV_maxWB and SUV_meanWB at prognostication.