Spectroscopy in prostate cancer: hope or hype?
Clinical applications of image-based radiation therapy for the study of prostate cancer have expanded significantly over the past years. The results of recent studies of magnetic resonance imaging (MRI) combined with magnetic resonance spectroscopic imaging (MRSI) demonstrate that the MRI/MRSI exam is a unique method by which to noninvasively study the cellular metabolism and anatomy of the prostate. This technology has the potential to define the tumor volume through functional or metabolic imaging. The results of current MRI/ MRSI studies also provide evidence that the magnitude of metabolic changes in regions of cancer before therapy, as well as the extent of the time course of metabolic changes after therapy, may improve our understanding of cancer aggressiveness. Assessment of cancer spread outside the prostate can be significantly improved by combining MRI findings with estimates of metabolic abnormalities provided by MRSI. Clinically, combined MRI/MRSI has already demonstrated a potential for improved diagnosis, staging, and treatment planning for patients with prostate cancer. Additional studies will reveal both the positive aspects and clinical challenges of MRI/