239 ACCURACY OF PHASED-ARRAY 3.0-T MR IMAGING IN PREDICTING EXTRACAPSULAR EXTENSION AND INFLUENCE ON THE DECISION TO PRESERVE NEUROVASCULAR BUNDLES AT ROBOTIC ASSISTED LAPAROSCOPIC RADICAL PROSTATECTOMY

Abstract

INTRODUCTION AND OBJECTIVES: To evaluate the accuracy of preoperative phased-array 3.0-T magnetic resonance imaging (MRI) for local staging of prostate cancer (PCa) and its influence on the decision to preserve neurovascular bundles at robotic-assisted laparoscopic radical prostatectomy (RALRP). METHODS: A total of 353 patients with biopsyproved PCa were included in this retrospective study between January 2008 and December 2011. All patients underwent preoperative 3.0-T MRI before RALRP and staging results of 3.0-T MRI were correlated with the pathological findings. The extent of neurovascular bundle sparing was initially determined on the basis of the clinical information and nerve sparing surgical plan was reevaluated after review of the MRI report. Analysis about the prediction extracapsular extension (ECE) of subgroups according to D’Amico risk classification was performed. RESULTS: The staging association between MRI and pathologic results showed correct staging in 261 (73.9%), overstaging in 43 (12.2%), and understaging in 49 (13.9%) patients. The sensitivity, specificity, positive and negative predictive value for predicting ECE and overall accuracy were 55.9%, 82.2%, 59.1%, 80.2%, and 73.9%, respectively. The planned surgical technique at first was changed in 83 (24%) of the 353 patients after review of the MRI reports. In 43 (52%) of the 83 patients, surgery was changed from no nerve sparing to nerve sparing procedure. In the rest (48%) of the 83 patients, surgery was changed from bilateral nerve sparing to no or unilateral nerve sparing procedure. The sensitivity of prediction of ECE was a tendency to increase from low risk to high risk group and there was statistically significant difference (33%, 46%, 80%, p 0.001). CONCLUSIONS: The phased-array 3.0-T MRI gives promising results in detecting ECE and is useful for planning the extent of nerve sparing at RALRP lacked haptic feedback. Preoperative 3.0-T MRI in patients of high risk group especially appears to be very helpful assessment modality.