Potential of Metabolic MRI to Address Unmet Clinical Needs in Localised Kidney Cancer

Renal cell carcinoma (RCC) is a major global health issue with an increasing incidence and mortality rate. Current diagnostic methods are either invasive or limited in their ability to accurately differentiate between benign and malignant tumours and to predict early treatment response. This can lead to incorrect diagnosis, delayed treatment, patient anxiety, and suboptimal outcomes. RCC subtypes are known to exhibit distinct metabolic alterations, for example in glucose metabolism. These metabolic phenotypes offer potential targets for non-invasive imaging techniques to improve diagnosis and treatment, but current clinically available metabolic imaging tools such as ¹⁸F-FDG-PET and ^99mTc-sestamibi SPECT have limitations. Therefore, new approaches are required to assess this metabolism, and novel metabolic MRI techniques including hyperpolarised [1-¹³C]pyruvate MRI and deuterium metabolic imaging offer promising alternatives. These techniques are non-radioactive, demonstrate spatial metabolic heterogeneity, and can probe metabolic flux beyond tracer uptake. This review aims to explore the potential of metabolic MRI in the clinical management of RCC by (1) summarising current clinical guidelines; (2) reviewing metabolic heterogeneity across RCC subtypes; (3) discussing the potential of metabolic MRI to advance the understanding of in vivo metabolism; (4) and finally suggesting future directions for research in this field.