Hyperpolarized Metabolic Imaging Detects Latent Hepatocellular Carcinoma Domains Surviving Locoregional Therapy.Hepatology 2019Hep
Advances in cancer treatment have improved survival; however, local recurrence and metastatic disease-the principal causes of cancer mortality-have limited the ability to achieve durable remissions. Local recurrences arise from latent tumor cells that survive therapy and are not detectable by conventional clinical imaging techniques. Local recurrence after transarterial embolization (TAE) of hepatocellular carcinoma (HCC) provides a compelling clinical correlate of this phenomenon. In response to TAE-induced ischemia, HCC cells adapt their growth program to effect a latent phenotype that precedes local recurrence. In this study, we characterize and leverage the metabolic reprogramming demonstrated by latent HCC cells in response to TAE-induced ischemia to enable their detection in vivo using dynamic nuclear polarization magnetic resonance spectroscopic imaging (DNP-MRSI) of 13 Carbon-labeled substrates. Under TAE-induced ischemia, latent HCC cells demonstrate reduced metabolism and develop a dependence on glycolytic flux to lactate. Despite the hypometabolic state of these cells, DNP-MRSI of 1-13 C-pyruvate and its downstream metabolites, 1-13 C-lactate and 1-13 C-alanine, predicted histologic viability. These studies provide a novel paradigm for imaging latent, treatment-refractory cancer cells that are undetectable using existing clinical imaging paradigms suggesting that DNP-MRSI provides a unique technology for this application.