³¹P MRSI Studies in Patients with Cancer

Many years of research and development culminated in the establishment of phosphorous-31 (³¹P) magnetic resonance spectroscopy (MRS) as a powerful tool in the characterization of cancer microenvironment. ³¹P MRS provides vital information on cancer bioenergetics, phospholipid biosynthesis, and pH, which latter is linked to tumor vasculature and oxygen consumption. Changes in cancer microenvironment during tumor progression or in response to therapy will result in changes in these biomarkers, which manifest itself as alterations in the localized ³¹P MR spectrum. Moreover, as the ³¹P MR spectra represent metabolism rather than morphology, changes in tumor microenvironment can be observed at an early stage. Thus, ³¹P MRS localized or imaged (MRSI) to the tumor is a powerful tool in the assessment of tumor therapy response. The combination of magnetic resonance imaging (MRI) with ³¹P MRSI is expected to improve cancer treatment by personalizing therapy and minimizing adverse effects, enabling better patient care. Here, we review state-of-the-art ³¹P MRSI as a noninvasive tool to assess unique relevant biomarkers from cancer in patients in vivo.