Determination of the time for maximal response to neoadjuvant hormone therapy for prostate cancer using magnetic resonance with spectroscopy (MRSI) and dynamic contrast enhancement (DCEMR)

Purpose: To determine the time-dependent metabolic and angiogenic changes that occur in prostate cancer (CaP) during neoadjuvant hormone therapy (HT), using a combination of MRSI and DCEMR analysis. Materials and methods: This is a prospective study on a population of non-metastatic CaP submitted to neoadjuvant HT prior to radiation therapy. All cases homogeneously received a 6-month period of neoadjuvant HT using leuprorelin acetate 7.5 mg every 28 days. In all cases, a MRSI/DCEMR study was performed at baseline (pretreatment) and at regular intervals (4, 12, 24 weeks) during HT. Serum PSA was measured at baseline and at the same intervals (4, 12, 24 weeks). All MRI examinations were performed on a commercially available 3 T scanner. Results: There was a significant ( P < 0.01) time-dependent loss of all prostate metabolites during HT. In regions of CaP no significant variation in the absolute value of metabolites was reported at 1-month interval and a higher variation was observed at 24-week compared with 12-week interval. A complete metabolic atrophy was a common feature (30%) at a 24-week interval of HT, but not at short (4-week 0%), and lower at an intermediate interval (12-week 10%). At DCEMR, onset time and time to peak parameters significantly (P < 0.05) increased at 12- and 24-week intervals. Conclusions: To individualize neoadjuvant HT courses prior to definitive treatment, the combination of MRSI and DCEMR may represent a valid noninvasive method, and the addition to PSA data could be used to better assess the time-dependent efficacy of HT in our patients. (C) 2012 Elsevier Inc. All rights reserved.