Protocol for producing hyperpolarized 13C-bicarbonate for clinical MRI of extracellular pH in aggressive tumors

Changhua Mu; Xiaoxi Liu; Andrew Riselli; James Slater; Evelyn Escobar; Duy Dang; Scott Drapeau; Romelyn Delos Santos; Stacy Andosca; Hao Nguyen; Peder E Z Larson; Robert Bok; Daniel B Vigneron; John Kurhanewicz; David M Wilson; Robert R Flavell

doi:10.1016/j.xpro.2024.103091

Protocol for producing hyperpolarized ¹³C-bicarbonate for clinical MRI of extracellular pH in aggressive tumors

STAR Protoc. 2024 Sep 20;5(3):103091. doi: 10.1016/j.xpro.2024.103091. Epub 2024 Jun 28.

Authors

Affiliations

¹ Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94158, USA. Electronic address: [email protected].
² Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94158, USA.
³ Makers Lab, Library, University of California, San Francisco, San Francisco, CA 94143, USA.
⁴ Department of Urology, University of California, San Francisco, San Francisco, CA 94143, USA.
⁵ Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA.

Abstract

Tumor acidosis is one of the hallmarks indicating the initiation and progression of various cancers. Here, we present a protocol for preparing a hyperpolarized (HP) ¹³C-bicarbonate tissue pH MRI imaging contrast agent to detect aggressive tumors. We describe the steps for the formulation and polarization of a precursor molecule ¹³C-glycerol carbonate (¹³C-GLC), the post-dissolution reaction, and converting HP ¹³C-GLC to an injectable HP ¹³C-bicarbonate solution. We then detail procedures for MRI data acquisition to generate tumor pH maps for assessing tumor aggressiveness. For complete details on the use and execution of this protocol, please refer to Mu et al.¹.

Keywords: Biotechnology and bioengineering; Cancer; Chemistry; Clinical Protocol; Health Sciences; Metabolism; Molecular/Chemical Probes.

MeSH terms

Animals
Bicarbonates* / metabolism
Carbon Isotopes* / chemistry
Contrast Media / chemistry
Humans
Hydrogen-Ion Concentration
Magnetic Resonance Imaging* / methods
Mice
Neoplasms / diagnostic imaging
Neoplasms / metabolism

Substances

Bicarbonates
Carbon Isotopes
Contrast Media
Carbon-13