Imaging of tumor metabolism: MR spectroscopy

Reprogrammed tumor metabolism, which is characterized by alterations in glucose/lactate, glutamate/glutamine, choline, and glycine metabolism, is a hallmark of cancer. Recent findings are starting to unravel the interplay between oncogenic signaling pathways and aberrant tumor metabolism, and this has renewed the interest in imaging tumor metabolism. Changes in tumor metabolism modify the microenvironment and lead to the evolution and progression of primary tumors, as well as the development of tumor metastases. Magnetic resonance spectroscopy (MRS) provides a noninvasive way to examine tumor metabolism in living systems, ranging from cultured cancer cells, to tumor models in experimental animals, to humans in the clinical setting. In addition, the use of stable nonradioactive MR-active isotopes such as 31P, 19F, and 13C allows us to track the metabolism of molecular probes that contain these nuclei in tumors. With its high translational potential, MRS can provide prognostic information and can be used to monitor treatment responses in tumors. This book chapter covers the breadths of multinuclear MRS of tumor metabolism with a focus on preclinical studies.