UCSF researchers test out new scanning technology - ABC news
The accurate characterization of prostate cancer is a major problem in the management of individual prostate cancer patients and in monitoring therapy. To address this pressing need, we have developed over the past 25 years a large research program to develop new anatomic and metabolic (MR spectroscopic imaging, MRSI) methods to provide an improved assessment of prostate cancer in individual patients. This has been a truly translational, multidisciplinary research project that has ranged from basic MR development to now routine clinical usage of these magnetic resonance imaging tools in the clinic. In conjunction with GE Healthcare we developed a commercial MRI/MRSI staging exam ("PROSE") for prostate cancer patients, and provided the leadership and training for an NIH funded multi-center trial of this commercial exam (ACRIN 3359). Additionally we have been investigating other imaging methods that can provide additional functional information within the same MR staging exam. Specifically, we have developed a multiparametric MR prostate cancer imaging exam, that includes T2- weighted MR, proton MR spectroscopic imaging, diffusion weighted imaging, dynamic contrast enhanced MR, and quantitative T2 weighted imaging. In collaboration with GE Healthcare and funded by the NIH we are optimizing and clinically validating this multiparametric prostate MR exam. I have directed the UCSF prostate imaging program, now called the Prostate Imaging Research Interest Group, in the Department of Radiology and Biomedical Imaging for the last 18 years and have applied these advanced imaging techniques in over 6,000 patients. In a number of ongoing grants, we are investigating the ability of multiparametric imaging to detect and characterize the extent and aggressiveness of prostate cancer for improved therapeutic selection, treatment planning, and therapeutic follow-up. We are also applying multiparametric imaging for direct MR guided biopsy and therapy. We currently have a FDA approved device for direct MR guided prostate biopsies, and are in the process of starting a MR Guided high intensity focused ultrasound prostate cancer treatment program.
We are also using multi-parametric in vivo imaging data to target cancer tissues in prostate cancer patients who undergo biopsy and/or radical prostatectomy for prostate cancer for the purpose of new biomarker development, validation and clinical translation. 1H HR-MAS is a non-destructive ex vivo technique that can enhance spectral resolution in spectroscopic examinations of intact biological tissues prior to the pathologic, immunohistochemical and genetic and proteomic analysis of the same tissue sample. This imaging biomarker discovery research has lead to the establishment of the Biomedical NMR lab, which I direct. The Biomedical NMR lab is a UCSF research resource and is being utilized by a large number of UCSF investigators performing biomarker studies of a variety of diseases.
We have also been involved in the development and clinical translation of an extraordinary new molecular imaging technique utilizing hyperpolarized 13C labeled metabolic substrates that has the potential to revolutionize the way we use MR imaging in the risk assessment of prostate cancer patients. Hyperpolarized (HP) 13C MR is a new molecular imaging technique that allows rapid and noninvasive monitoring of dynamic pathway-specific metabolic and physiologic processes. Hyperpolarization, achieved through the dynamic nuclear polarization (DNP) technique, can provide unprecedented gain in sensitivity (10,000 – 100,000 fold increase) for imaging 13C-labeled bio-molecules that are endogenous, nontoxic, and nonradioactive. Metabolically active HP 13C-labeled compounds can be delivered to living systems where the substrate is metabolized and the products can be imaged in real time. The ability to detect down-stream metabolism, specifically the metabolic flux of HP 13C-pyruvate to lactate catalyzed by lactate dehydrogenase (LDH), has shown great potential for not only detecting prostate cancer, but for also assessing the aggressiveness (pathologic grade) of the cancer and response to therapy. The first DNP polarizer for human studies has been sited at UCSF and we have successfully completed the first clinical trial of 13C MR metabolic imaging in patients with prostate cancer. Future trials clinical studies of HP 13C MR in patients with advanced prostate cancer are planned to investigate the clinical value of this technique and new technical developments are underway to allow the assessment of metastatic prostate cancer. Moreover, we have been involved in the translation of this technology to other urologic cancers and diseases and in the development of new hyperpolarized MR probes.