Imaging breast cancer using hyperpolarized carbon-13 MRI

Area of Science:

• Oncology
• Medical Imaging
• Biochemistry

Background:

• Accurate assessment of breast cancer metabolism is crucial for effective treatment strategies.
• Current imaging techniques may not fully capture the dynamic metabolic processes within tumors.
• Hyperpolarized ¹³C Magnetic Resonance Spectroscopic Imaging (MRSI) offers a novel approach to visualize metabolic pathways in vivo.

Purpose of the Study:

• To investigate the feasibility and safety of using hyperpolarized ¹³C MRSI to image tumor metabolism in breast cancer patients.
• To explore the metabolic label exchange between injected [1-¹³C]pyruvate and endogenous lactate within tumors.
• To correlate metabolic imaging findings with key tumor biomarkers.

Main Methods:

• Recruited treatment-naïve breast cancer patients with diverse tumor subtypes.
• Administered hyperpolarized [1-¹³C]pyruvate and performed dynamic ¹³C MRSI.
• Quantified expression of lactate dehydrogenase A (LDHA), HIF1α, MCT1, and MCT4 using immunohistochemistry and RNA sequencing.

Main Results:

• Demonstrated the feasibility and safety of hyperpolarized ¹³C MRI in early breast cancer.
• Observed significant intertumoral and intratumoral heterogeneity in hyperpolarized pyruvate and lactate signals.
• Found a significant correlation between the lactate-to-pyruvate ratio (LAC/PYR) and tumor volume, MCT1 expression, and HIF1α levels.

Conclusions:

• Hyperpolarized ¹³C MRSI is a feasible technique for imaging breast cancer metabolism.
• The study highlights significant metabolic heterogeneity within and between breast tumors.
• Lactate labeling observed via MRSI correlates with key markers of tumor aggressiveness and hypoxia, suggesting potential for clinical application.