Is Apparent Diffusion Coefficient Established as an Imaging Biomarker for Stereotactic Body Radiation Therapy Assessment in Hepatocellular Carcinoma?

In this article, as part of this special issue on biomarkers of early response, we review currently available reports regarding magnetic resonance imaging apparent diffusion coefficient (ADC) changes in hepatocellular carcinoma (HCC) in response to stereotactic body radiation therapy. We compare diffusion image acquisition, ADC analysis, methods for HCC response assessment, and statistical methods for prediction of local tumor progression by ADC metrics. We discuss the pros and cons of these studies. Following detailed analyses of existing investigations, we cannot conclude that ADC is established as an imaging biomarker for stereotactic body radiation therapy assessment in HCC.

Automated summary

In this article, the available reports on magnetic resonance imaging apparent diffusion coefficient (ADC) changes in hepatocellular carcinoma (HCC) in response to stereotactic body radiation therapy are reviewed. The comparison of various diffusion image acquisition methods, ADC analysis methods, HCC response assessment methods, and statistical methods for predicting local tumor progression by ADC metrics are discussed, along with the pros and cons of these studies. Based on the detailed analyses of existing investigations, the conclusion that ADC is established as an imaging biomarker for stereotactic body radiation therapy assessment in HCC cannot be drawn.