Hyperpolarized C-13 Pyruvate as a Biomarker in Patients With Advanced Solid Tumor Malignancies

This is a single center prospective imaging study investigating the utility of hyperpolarized C-13 pyruvate/metabolic magnetic resonance (MR) imaging. The current protocol will serve as a companion imaging biomarker study paired with therapeutic trials of PI3K/mTOR pathway inhibitors (e.g. CUDC-907, BYL719), as well as a stand-alone protocol for patients treated with standard-of-care therapies inhibiting the PI3K/mTOR signaling pathway (eg. everolimus). In Part A (run-in feasibility phase), patients will undergo imaging at a single time point, without paired tumor biopsy. There will be no follow up imaging or requirement for treatment with PI3K/mTOR pathway inhibitor. Iterative adjustment of radiofrequency coil geometry and imaging sequences will be undertaken to optimize intra-tumoral hyperpolarized pyruvate/lactate signal-to-noise ratio. In Part B, patients will undergo paired baseline hyperpolarized C-13 pyruvate imaging + tumor biopsy,then initiate treatment with agent inhibiting the PI3K/mTOR pathway. After 21 days (+/- 14 days), patients will undergo repeat hyperpolarized C-13 pyruvate MR imaging + tumor biopsy. Patients will subsequently be treated with PI3K/mTOR pathway inhibitor until disease progression, unacceptable toxicity, or patient/physician decision to discontinue therapy.