Timing of Metabolic Response Monitoring During Erlotinib Treatment in Non–Small Cell Lung Cancer

Abstract

The purpose of this study was to prospectively evaluate the timing of metabolic response monitoring with 18 F-FDG PET of (neoadjuvant) erlotinib treatment in patients with early-stage non-small cell lung cancer. Methods: This study was designed as an open-label phase II trial performed in 4 hospitals in The Netherlands. Patients received preoperative erlotinib (150 mg) once daily for 3 wk. Response evaluation was performed after 4-7 d and at 3 wk with 18 F-FDG PET/CT scans. Tumor 18 F-FDG uptake and changes were measured as standardized uptake values (SUVs). The metabolic response was classified on the basis of European Organization for Research and Treatment of Cancer criteria (.25% decrease in the maximum SUV) and was compared with histopathologic regression as observed in the resection specimen. Results: From December 2006 to November 2010, 60 patients with non-small cell lung cancer eligible for surgical resection were enrolled in this study. For 43 patients (18 men and 25 women), baseline 18 F-FDG PET/CT scans as well as both monitoring scans and histopathologic response monitoring were available. A partial metabolic response on 18 F-FDG PET/CT scans was observed for 10 patients (23%) after 1 wk and for 14 patients (33%) after 3 wk. Histopathologic examination revealed regression (necrosis of .50%) in 11 patients (26%). In these patients, the maximum SUV decreased by a mean of 17% within 1 wk and a mean of 31% at 3 wk. Seven patients were identified as responders within 1 wk. Conclusion: Response monitoring with 18 F-FDG PET/CT within 1 wk after the start of erlotinib treatment identified approximately 64% of histopathologic responders on the basis of European Organization for Research and Treatment of Cancer criteria.

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

“…Consistent with previous reports [3][4][5][6][7][8][9], the results of our study demonstrate that assessment of early FDG-PET response using the EORTC criteria predicts OS in NSCLC patients treated with erlotinib. In our report, the number and timing of FDG-PET scans (at baseline and on days 14 and 56) were in line with the protocol utilized by Mileshkin et al [3].…”

“…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.…”

“…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].…”

PET Imaging-Based Phenotyping as a Predictive Biomarker of Response to Tyrosine Kinase Inhibitor Therapy in Non-small Cell Lung Cancer: Are We There Yet?

“…There is emerging evidence that the FDG-PET imagingbased phenotype of response might be an effective early predictor of lung cancer response to TKIs such as erlotinib and gefitinib [35][36][37][38][39][40][41][42][43][44][45]. Recent studies showed that a reduction in FDG tumor uptake observed at 2 days [37,38], 1 week [39], 2 weeks [40,41], and 3 weeks [39,41,42] after treatment with erlotinib or gefitinib, predicts early tumor response as confirmed by CT 4 and 6 weeks later. In contrast, SUVmax has been reported to increase significantly in non-responding patients.…”

Tumor heterogeneity on 18F-FDG-PET/CT for response monitoring in non-small cell lung cancer treated with erlotinib

“…Tumor heterogeneity on 18 F-FDG-PET/CT for response monitoring in non-small cell lung cancer treated with erlotinib Early response measured with FDG-PET/CT seems to correlate to histopathological response (11). However, there is on ongoing search for reliable parameters to measure response with FDG-PET/CT (12).…”