3-D Textural Analysis of 2-[¹⁸F]FDG PET and Ki67 Expression in Nonsmall Cell Lung Cancer

This is the authors' abstract. We don't add key points for this paper.

The immunohistochemical determination of the Ki67 expression is regarded as a reliable method to monitor nonsmall cell lung cancer (NSCLC) proliferation. However, cancer tissues are not uniform and the use of a small tumor sample in biopsy may not be accurate. Although positron emission tomography (PET) represents an alternative to biopsy, by providing the 3-D functional and morphological distribution of cancer cells across the entire tumor volume, standardized uptake values (SUVs) exhibit poor accuracy. The purpose of this study is to identify quantitative features in 2-[18F]FDG PET images uniquely correlated with proliferating lung cancer cells that may perform better than SUVs in the evaluation of lung cancer proliferation. By using a xenograft NSCLC model implanted in 19 mice, we found that 89 textural parameters extracted from 3-D 2-[18F]FDG uptake can be described by 6 independent principal components accounting for 95% of the total variance. One of these components features a significant and univocal correlation with 3-D-stacked Ki67 staining immunohistochemical images ($|r|>0.6; P< 0.05/6$, including compensation for multiple comparisons). Furthermore, the values of these components extracted from the PET images ofin vivoandex vivoexplanted NSCLC cancers exhibit a strong correlation, verifying the stability of the segmentation method.