Comprehensive Imaging Characterization of Colorectal Liver Metastases

Abstract

Colorectal liver metastases (CRLM) have heterogenous histopathological and immunohistochemical phenotypes, which are associated with variable responses to treatment and outcomes. However, this information is usually only available after resection, and therefore of limited value in treatment planning. Improved techniques for in vivo disease assessment, which can characterise the variable tumour biology, would support further personalization of management strategies. Advanced imaging of CRLM including multiparametric MRI and functional imaging techniques have the potential to provide clinically-actionable phenotypic characterisation. This includes assessment of the tumour-liver interface, internal tumour components and treatment response. Advanced analysis techniques, including radiomics and machine learning now have a growing role in assessment of imaging, providing high-dimensional imaging feature extraction which can be linked to clinical relevant tumour phenotypes, such as a the Consensus Molecular Subtypes (CMS). In this review, we outline how imaging techniques could reproducibly characterize the histopathological features of CRLM, with several matched imaging and histology examples to illustrate these features, and discuss the oncological relevance of these features. Finally, we discuss the future challenges and opportunities of CRLM imaging, with a focus on the potential value of advanced analytics including radiomics and artificial intelligence, to help inform future research in this rapidly moving field.

Primäre und sekundäre Lebertumore

“…Lebermetastasen haben eine deutlich höhere Prävalenz und eine größere Heterogenität an histopathologischen und immunhistochemischen Phenotypen als primäre Malignome der Leber [18,19,20]. Dabei kann eine Vielzahl maligner Tumoren, einschließlich des gastrointestinalen Systems, des urogenitalen Systems, des gynäkologischen und des neuroendokrinen Systems, wie aber auch Weichteilsarkome, Melanome und Lymphome in die Leber metastasieren [21].…”

Liver metastasis in soft tissue sarcoma at initial presentation

“…The detection of liver metastasis at initial presentation is also of paramount importance, since this finding critically affects cancer staging and treatment for each patient. Ultrasonography, contrast‐enhanced CT, magnetic resonance imaging with hepatospecific contrast agents, and positron emission tomography‐CT are the most frequently used imaging modalities 14 . In contrast, regarding STS, those patients for whom abdominal screening should be prioritized have not been clarified.…”

“…Ultrasonography, contrast-enhanced CT, magnetic resonance imaging with hepatospecific contrast agents, and positron emission tomography-CT are the most frequently used imaging modalities. 14 In contrast, regarding STS, those patients for whom abdominal screening should be prioritized have not been clarified.…”

A Review of Radiomics in Predicting Therapeutic Response in Colorectal Liver Metastases: From Traditional to Artificial Intelligence Techniques

“…CT texture analysis is useful for diagnosing, staging, and assessing therapy response in several studies [ 12 , 14 , 16 , 35 ]. Moreover, imaging techniques can potentially characterize the histopathological features of CRCLM [ 36 ]. For example, the feature of the interface between the normal liver and tumor influences the chemotherapy selection [ 36 ].…”

“…Moreover, imaging techniques can potentially characterize the histopathological features of CRCLM [ 36 ]. For example, the feature of the interface between the normal liver and tumor influences the chemotherapy selection [ 36 ]. However, there is an absence of studies that provide robust validation of imaging techniques [ 36 ].…”