UCSF

Prostate cancer is one of the most common cancers in men and second leading cause of death cancer in the United States of America. Current clinical imaging modalities provide limited information on prostate cancer aggressiveness and response to therapy required for optimal patient management. To reduce the mortality rates, early detection and diagnosis of prostate cancer is crucial. Thus, there is a clinical need for improved noninvasive accurate histopathologic diagnosis and grading of prostate cancer. Currently, transrectal ultrasonography (TRUS)–guided biopsy is the standard approach for histopathologic diagnosis and grading of prostate cancer. However, TRUS is limited for directly visualizing and targeting prostate lesions and therefore the fusion of magnetic resonance (MR) images with US was developed to overcome many of these limitations. The development of endorectal (ER) coils has further improved prostate tumor visualization on MR images as the endorectal coil used in an MRI-guided prostate biopsy helps provide more detailed images from the prostate and surrounding structures. However, conventional anatomic and diffusion MR images do not provide metabolic information on prostate cancer aggressiveness and extent. Recent studies with the emerging hyperpolarized (HP) carbon-13 (13C) MR imaging technique have shown that hyperpolarized (HP) 13C-pyruvate MRI in a rapid 1-minute addition to conventional proton MRI exams can detect metabolic reprogramming in prostate cancer improving the detection of aggressive cancers and for monitoring response to therapy. Dual-agent ([1-13C]-pyruvate, [1-13C,15N2]-urea) hyperpolarized 13C MRI can also be used to simultaneously assess tumor metabolism and tissue perfusion in patients with localized prostate cancer; Thus, this project was designed to develop specialized hardware and software to enable multiparametric MR incorporating hyperpolarized (HP) 13C MR molecular imaging for improved characterization and MR- US fusion biopsy guidance. In this dissertation project, new methods and detector hardware to acquire and display 13C-pyruvate to 13C-lactate conversion rate constants (kPL) images were developed and applied for guiding MR-US fusion biopsies in prostate cancer patients for the first time.