Dynamic Nuclear Polarization MR Spectroscopic Imaging for Diagnosis and Treatment Response Assessment in Hepatocellular Carcinoma

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Hepatocellular carcinoma (HCC) is the most rapidly rising cause of cancer mortality in the United States. The majority of patients with HCC present with incurable disease at diagnosis and, despite the approval of targeted therapies, life expectancy remains less than 20 months. The diagnosis of HCC as well as its response to treatment rely primarily on imaging biomarkers which have replaced tissue-based methods. Recent studies demonstrate that the dismal prognosis for these patients issues, at least in part, from deficiencies of current clinical imaging paradigms in diagnosing HCC as well as in identifying residual or recurrent HCC after treatment. Clinical imaging paradigms for HCC diagnosis and the assessment of treatment response are based on anatomic imaging features that often fail to identify HCCs or provide functional measures of response to targeted therapies. Indeed, the sensitivity of standard-of-care (SOC) contrast-enhanced (CE) MRI for small HCCs can be as low as 20%. Similarly, SOC imaging provides inadequate assessments of response to therapies. Addressing this deficiency requires the development of new imaging paradigms that provide functional measures of HCC biology to improve accuracy, sensitivity and specificity as well as inform the application of therapeutics. The development of novel functional imaging strategies for HCC has been limited by the absence of methodologies that can tailor imaging probe selection to the relevant HCC biology as well as a dearth of representative animal models. Using genome editing and metabolomics, our laboratory has demonstrated the fundamental dependence of HCC cells on lactate dehydrogenase and NADPH-dependent reductases to be promising imaging targets for Dynamic Nuclear Polarization 13Carbon Magnetic Resonance Spectroscopic Imaging (DNP-13C-MRSI), an emerging imaging technology. The proposed project will build on this prior work to study the ability of DNP-13C-MRSI to: 1) improve the accuracy of diagnosis and treatment response assessment of HCC following SOC therapies as compared to conventional imaging and 2) inform treatment selection. We hypothesize that DNP-13C-MRSI provides a unique technology through which to leverage fundamental enzymatic dependencies of HCC cells and enable functional molecular imaging for diagnosis and treatment response assessment. To test this hypothesis the proposed project will use unique animal models of HCC developed in our lab to pursue three aims: (1) to optimize a DNP-13C-MRSI pulse sequence that enables sensitive, accurate and reproducible measurements of regional pyruvate metabolism in autochthonous HCCs at high spatial resolution; (2) to determine the sensitivity, specificity and accuracy of DNP-13C-MRSI of HP 1-13C- pyruvate uptake and metabolism for identifying HCCs; and (3) to determine the accuracy of DNP-13C-MRSI of HP 1-13C-pyruvate and/or 1-13C-dehydroascorbic acid (DHA) for identifying and characterizing residual disease/local recurrence following TAE as compared to SOC imaging. The achievement of the proposed aims holds the potential to transform the imaging and treatment of patients with HCC, a devastating disease.