Diagnostic Performance of 1.5 Tesla Endorectal MR Imaging and MR Spectroscopic Imaging for the Detection of Locally Recurrent Prostate Cancer after External Beam Radiation Therapy

INTRODUCTION: recurrent disease after external beam radiotherapy is suspected after biochemical failure (rising PSA) and may be local, systemic, or both. Transrectal ultrasound guided biopsy is the standard of care for the detection of local recurrence, but is invasive and may miss tumors since only a small fraction of the gland is sampled. Although endorectal T2-weighted MR imaging has emerged as an exciting new modality for the detection and characterization of prostate cancer, it is limited by post-treatment loss of zonal anatomy and diffuse low T2 signal, which hinder tumor detection .