APT imaging of hepatocellular carcinoma signals an effective therapeutic response in advance of tumor shrinkage

Aim: The aim of this study was to assess the utility of weighted amide proton transfer (APT_w) MRI in three different rodent models of hepatocellular carcinoma (HCC). Methods: APT_w MRI was evaluated in models of diethylnitrosamine (DEN) induced HCC, N1S1 syngeneic orthotopic xenograft and human HepG2 ectopic xenograft. Results: All models of HCC showed a higher APT_w signal over the surrounding normal tissues. In the DEN model, the APT_w signal could differentiate HCC lesions from benign nodules. Intra-arterial administration of low-density lipoprotein docosahexaenoic acid (LDL-DHA) nanoparticles to N1S1 xenografts rapidly lowered the tumor APT_w signal within 72 h. Direct injections of LDL-DHA nanoparticles into HepG2 xenografts also showed similar therapeutic responses. Conclusion: We have demonstrated the utility of APT_w imaging in the diagnostic/therapeutic management of HCC.