Role of dynamic contrast-enhanced magnetic resonance (MR) imaging and proton MR spectroscopic imaging in the detection of local recurrence after radical prostatectomy for prostate cancer.

OBJECTIVES To assess the accuracy of magnetic resonance (MR) spectroscopic imaging (1H-MRSI) and dynamic contrast-enhanced MR (DCEMR) in the depiction of local prostate cancer recurrence in patients with biochemical progression after radical prostatectomy (RP). MATERIALS AND METHODS 1H-MRSI and DCEMR were performed in 70 patients at high risk of local recurrence after RP. The population was divided on the basis of the clinical validation of MR results with the use of a transrectal ultrasound biopsy examination in a group of 50 patients (group A) and the prostate-specific antigen (PSA) serum level restitution after external beam radiotherapy, in a group of 20 patients (group B). RESULTS In group A, 1H-MRSI analysis alone showed a sensitivity of 84% and a specificity of 88%; the DCEMR analysis alone, a sensitivity of 71% and a specificity of 94%; combined 1HMRSI-DCEMR, a sensitivity of 87% and specificity of 94%. Areas under the receiver operating characteristic (ROC) curve for 1HMRSI, DCEMR, and combined 1HMRSI /DCEMR were 0.942, 0.93,1 and 0.964, respectively. In group B, 1HMRSI alone showed a sensitivity of 71% and a specificity of 83%; DCEMR, a sensitivity of 79% and a specificity of 100%; combined 1HMRSI and DCEMR, a sensitivity of 86% and a specificity of 100%. Areas under the ROC curve for each of these groups were 0.81, 0.923, and 0.94, respectively. CONCLUSION Our results show that combined 1H-MRSI and DCMRE is an accurate method to identify local prostate cancer recurrence in patients with biochemical progression after RP.