ilot Study of Volume Measurement as a Method of Tumor

Download pose: Tissue biomarker discovery is potentially limited by conventional tumor measurement techs, which have an uncertain ability to accurately distinguish sensitive and resistant tumors. Semiated volumetric measurement of computed tomography imaging has the potential to more tely capture tumor growth dynamics, allowing for more exact separation of sensitive and resistant s and a more accurate comparison of tissue characteristics. erimental Design: Forty-eight patients with early stage non–small cell lung cancer and clinical teristics of sensitivity to gefitinib were studied. High-resolution computed tomography was done eline and after 3 weeks of gefitinib. Tumors were then resected and molecularly profiled. Unidimenand volumetric measurements were done using a semiautomated algorithm. Measurement changes valuated for their ability to differentiate tumors with and without sensitizing mutations. ults: Forty-four percent of tumors had epidermal growth factor receptor–sensitizing mutations. Reoperating characteristic curve analysis showed that volumetric measurement had a higher area une curve than unidimensional measurement for identifying tumors harboring sensitizing mutations .009). Tumor volume decrease of >24.9% was the imaging criteria best able to classify tumors with ithout sensitizing mutations (sensitivity, 90%; specificity, 89%). clusions: Volumetric tumor measurement was better than unidimensional tumor measurement at guishing tumors based on presence or absence of a sensitizing mutation. Use of volume-based ree assessment for the development of tissue biomarkers could reduce contamination between senspons sitive and resistant tumor populations, improving our ability to identify meaningful predictors of sensitivity. Clin Cancer Res; 16(18); 4647–53. ©2010 AACR.