This study evaluated the safety and feasibility of hyperpolarized [1-13C] pyruvate for noninvasive metabolic imaging in patients with prostate cancer. The hyperpolarized agent, which provides a 10,000-fold signal enhancement over conventional MRI, was injected into 31 patients with biopsy-proven localized prostate cancer. The agent was delivered rapidly, with uptake observed within 20 seconds of injection. No dose-limiting toxicities were observed, and the highest dose (0.43 ml/kg of 230 mM agent) provided the best signal-to-noise ratio. The study demonstrated that hyperpolarized [1-13C] lactate/ [1-13C] pyruvate ratios were elevated in regions of biopsy-proven cancer, indicating potential for noninvasive cancer diagnosis and treatment monitoring. The hyperpolarized agent was prepared using specialized equipment and delivered through a dedicated coil system. The study used various imaging techniques, including 1D and 2D dynamic MRSI, and single-time point MRSI, to assess the distribution and metabolism of the agent. The results showed that hyperpolarized [1-13C] pyruvate was rapidly taken up by the prostate and converted to lactate, with higher conversion rates in cancerous regions. The 1D and 2D dynamic MRSI data confirmed the presence of cancer and provided insights into tumor metabolism. The single-time point MRSI data also showed elevated lactate/pyruvate ratios in cancerous regions, which were consistent with the findings from the dynamic MRSI data. The study demonstrated that hyperpolarized [1-13C] pyruvate imaging could detect cancer in regions not visible on conventional imaging, highlighting its potential for improved cancer detection. The results suggest that this technique may be valuable for initial diagnosis and monitoring of treatment response in prostate cancer. The study also identified limitations, including the need for further research to optimize the imaging protocol and to validate the technique in larger patient populations. Future studies may benefit from advancements in hyperpolarized agent preparation and imaging technology, which could enhance the clinical application of this promising technique.This study evaluated the safety and feasibility of hyperpolarized [1-13C] pyruvate for noninvasive metabolic imaging in patients with prostate cancer. The hyperpolarized agent, which provides a 10,000-fold signal enhancement over conventional MRI, was injected into 31 patients with biopsy-proven localized prostate cancer. The agent was delivered rapidly, with uptake observed within 20 seconds of injection. No dose-limiting toxicities were observed, and the highest dose (0.43 ml/kg of 230 mM agent) provided the best signal-to-noise ratio. The study demonstrated that hyperpolarized [1-13C] lactate/ [1-13C] pyruvate ratios were elevated in regions of biopsy-proven cancer, indicating potential for noninvasive cancer diagnosis and treatment monitoring. The hyperpolarized agent was prepared using specialized equipment and delivered through a dedicated coil system. The study used various imaging techniques, including 1D and 2D dynamic MRSI, and single-time point MRSI, to assess the distribution and metabolism of the agent. The results showed that hyperpolarized [1-13C] pyruvate was rapidly taken up by the prostate and converted to lactate, with higher conversion rates in cancerous regions. The 1D and 2D dynamic MRSI data confirmed the presence of cancer and provided insights into tumor metabolism. The single-time point MRSI data also showed elevated lactate/pyruvate ratios in cancerous regions, which were consistent with the findings from the dynamic MRSI data. The study demonstrated that hyperpolarized [1-13C] pyruvate imaging could detect cancer in regions not visible on conventional imaging, highlighting its potential for improved cancer detection. The results suggest that this technique may be valuable for initial diagnosis and monitoring of treatment response in prostate cancer. The study also identified limitations, including the need for further research to optimize the imaging protocol and to validate the technique in larger patient populations. Future studies may benefit from advancements in hyperpolarized agent preparation and imaging technology, which could enhance the clinical application of this promising technique.