Androgen deprivation therapy (ADT) is being increasingly used as both a primary and neoadjuvant therapy for patients with localized prostate cancer (PCa). Our recent studies have demonstrated that the metabolic information provided by 3D MR spectroscopic imaging (MRSI) can improve the specificity of magnetic resonance imaging (MRI) in identifying prostate cancer prior to and after therapy. However, our preliminary data also indicate that the anatomic and metabolic atrophy induced by ADT is duration dependent and the ability of combined MRI/MRSI to assess the presence of residual/recurrent cancer can be reduced at certain times after therapy. Therefore, the time-course of anatomic and metabolic atrophy following hormone therapy needs to be established. Preliminary proton magic angle spinning nuclear magnetic resonance (1H MAS-NMR) spectroscopy studies of surgical specimens have also identified several metabolic changes that may further increase the specificity of MRSI for the identification of cancer after ADT. In this fellowship, serial in vivo MRI/MRSI data and 1H MAS-NMR data obtained from biopsy samples will be combined with clinical data to examine the anatomic and metabolic changes that occur in patients undergoing ADT. The goal of this work is to improve the MRI/MRSI assessment of cancer after hormone ablation and to better understand the biochemical consequences of ADT. The clinical importance of this work combined with Dr Swanson's strong interest and background in the application of NMR to biological questions and the extensive experience in MRI/MRSI of prostate that we have at UCSF makes this an ideal topic for his post-doctoral fellowship.