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

Response monitoring using fluorodeoxyglucose positron emission tomography acquired together with low dose computed tomography (FDG-PET/CT) textural features has potential in targeted treatment with erlotinib in non-small cell lung cancer (NSCLC) patients. Patients with substantial decrease of metabolic activity during erlotinib treatment will probably benefit from continued treatment. However, various aspects of the method (quantification tools, cut-off values, etc.) need to be standardized before the software becomes widely available in a similar manner as standardized uptake value (SUV) measurements. Heterogeneity on FDG-PET/CT opened an additional window for innovation but simultaneously a new challenge for molecular hybrid imaging.