Hepatic cancers and their response to chemoembolization therapy. Quantitative image-guided 31P magnetic resonance spectroscopy.

Rationale and Objectives: Hepatic embolization combined with intra-arterial administration of cytostatic drugs (chemoembolization) is frequently used to treat primary and metastatic cancers to the liver. Quantitative phosphorus-31 magnetic resonance spectroscopy (31P MRS) was used to assess the metabolic state of hepatic cancers and their metabolic response to chemoembolization.
Methods: Fifteen localized 31P MRS studies were performed on five patients with liver tumors. Thirteen healthy volunteers served as controls. Metabolite ratios and molar metabolite concentrations were calculated.
Results: Untreated hepatic tumors, relative to normal controls, showed elevated phosphomonoester/adenosine triphosphate (PME/ATP) ratios, reduced concentrations of ATP and inorganic phosphate (Pi), and normal phosphodiester (PDE) concentrations. As an acute response to chemoembolization, ATP, PME, and/or PDE concentrations diminished, whereas Pi concentrations increased or stayed relatively constant. Long-term follow-up after chemoembolization showed decreased PME/ATP and increased ATP concentrations in the absence of changes on standard magnetic resonance and computed tomographic images.
Conclusions: These preliminary spectroscopic data suggest that quantitative 31P MRS can be successfully used to monitor directly metabolic response to hepatic chemoembolization.