Heterogeneity Does Matter for Tumor Characterization

Excerpt

Heterogeneity is welcomed by sociologists because diversity is considered a virtue for an open dynamic society. As for tumor characterization, heterogeneity seems to be a stigma that is highly associated with aggressiveness of the tumor, ultimately leading to poorer outcome of patients. The textural features of radiologic imaging studies, such as computed tomography (CT) or magnetic resonance imaging (MRI), have been studied as imaging biomarkers for tumor characterization [1], and a new discipline has emerged called “radiomics” [2]. The imaging features have evolved to be correlated with gene profiling, yielding the so-called “radiogenomics”, which is reminiscent of a series of –omics in biology: genomics, proteomics, transcriptomics, epitranscriptomics, etc. Those –omics studies are typically characterized by a huge amount of data, and effective data handling is a new challenge for biologists. Oncological positron emission tomography/computed tomography (PET/CT) has also been intensively investigated for tumor characterization using ¹⁸F-FDG (¹⁸F-fluorodeoxyglucose) in most cases. The results of the recent radiomics approach of ¹⁸F-FDG PET/CT are thoroughly reviewed in the current issue by Lee [3]. There are so many technical hurdles like protocol harmonization, target volume determination, and a time-consuming analysis process that implementation of the PET/CT technology does not seem easy. However, a number of papers as introduced in the review paper may render readers to rethink the feasibility of the tumor heterogeneity analysis as an imaging biomarker for prediction of patients’ outcome. …