Metabolic tumor burden as marker of outcome in advanced EGFR wild-type NSCLC patients treated with erlotinib

TLG-S criteria are superior to both EORTC and PERCIST for predicting outcomes in patients with metastatic lung adenocarcinoma treated with erlotinib

“…Another recent report demonstrated that high TLG-S values were an independent predictor of survival in patients with advanced NSCLC who received erlotinib [19]. In that study, TLG-S was calculated by taking into account all of the measurable lesions in whole-body scans; in addition, TLG-S was dichotomized according to the median value [19]. Together, these findings indicate strong prognostic significance of TLG-S, although neither the extent of target lesions nor the definition of metabolic response have yet been standardized.…”

“…In that study, the authors defined TLG-S as the sum of up to five measurable target lesions; different cutoff values for defining the metabolic response were calculated as well [18]. Another recent report demonstrated that high TLG-S values were an independent predictor of survival in patients with advanced NSCLC who received erlotinib [19]. In that study, TLG-S was calculated by taking into account all of the measurable lesions in whole-body scans; in addition, TLG-S was dichotomized according to the median value [19].…”

“…Because several papers addressing these issues have been published [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19], we also performed a retrospective review of our cohort data. The first goal of the retrospective analysis was to investigate whether early FDG-PET assessment of treatment response using TLG-S would be superior to either local assessment with EORTC criteria or hottest-single-lesion assessment with PERCIST criteria for predicting 2-year survival outcomes.…”

“…Although patients carrying mutations of the EGFR gene generally respond better to tyrosine kinase inhibitors (TKIs) [1], erlotinib may improve survival even in subjects with EGFR wild-type tumors [2]. Several studies have shown that FDG-PET is a useful imaging modality for predicting response to erlotinib in patients with non-small cell lung cancer (NSCLC) [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. However, most of these studies used only the primary tumor as the target lesion for sequential imaging [3][4][5][6][7][8][9][10][11][12], and treatment response was largely assessed using the European Organization for Research and Treatment of Cancer (EORTC) criteria [3][4][5][6][7][8][9]20].…”

“…Other studies have evaluated treatment response using the Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST) [21], based on the measurement of a specific focus on the hottest single lesion, including the metastatic tumor [15,16]. Finally, other studies have used total lesion glycolysis measured using a systemic approach (TLG-S) based either on the sum of up to five measurable target lesions [18] or on all measurable lesions [19].…”