MR imaging of prostate cancer with an endorectal surface coil technique: correlation with whole-mount specimens.

Abstract

To evaluate the diagnostic accuracy of magnetic resonance (MR) imaging in staging prostate cancer with an endorectal surface coil technique. The authors prospectively evaluated MR images obtained with an endorectal surface coil from 70 consecutive patients with known prostate cancer. Gadopentetate dimeglumine was administered to 40 patients. Multiple sequences were used, including conventional and fast spin echo, with and without fat suppression. The readers were blinded to the MR findings unless bone or nodal metastasis was present. MR images were compared with whole-mount sections. The prospective staging accuracy for MR imaging was 51% (36 of 70 patients). Stage B disease was present in 27 patients (38%), stage C in 42 (60%), and stage D in one (1%). The retrospective staging accuracy was 67% (47 of 70 patients). Of the 42 patients with stage C disease, positive surgical margins were present in 36 (85%). Gadopentetate dimeglumine did not help detect or stage tumors. Further studies must be performed to determine the role of endorectal coil MR imaging in the staging of prostate cancer.