Metabolic Atrophy and 3T 1H - MR Spectroscopy Correlation After Radiation Therapy for Prostate Cancer.

To correlate 3 T Magnetic Resonance Spectroscopic Imaging (MRSI) with prostate specific antigen (PSA) in patients with prostate cancer (PC) treated with external beam radiation therapy to assess potential advantages of MRSI. 50 patients (age range 65-83 years) underwent PSA and MRSI surveillance before and 3,6,12,18 and 24 months after radiotherapy. Of the 50 patients examined, 13 patients completely responded to therapy showing metabolic atrophy (MA), defined as a choline-plus-creatine-to-citrate ratio (CC/C) < 0.2, at 3 months; in this group none had biochemical relapse (BR) (PSA nadir + 2 ng/mL) by the end of the follow-up. 35 patients out of 50 showed partial response to therapy (0.2 < CC/C < 0.8) at 3 and 6 months. 30 out of these 35 patients reached MA at 12 month, while 5 developed a recurrence (CC/C > 0.8). 3 of those with recurrence had a BR at 18 months and the other 2 at 24 months. 2 out of the 50 patients did not respond to the treatment showing persistent disease from the 3rd month (CC/C > 0.8); one patient showed BR at 6 and the other at 12 months. MRSI shows a greater potential than PSA in monitoring patients after radiotherapy, because it anticipates PSA nadir and especially BR. This article is protected by copyright. All rights reserved.