Endorectal 3D T2-weighted 1Â mm-slice thickness MRI for prostate cancer staging at 1.5Â Tesla: Should we reconsider the indirects signs of extracapsular extension according to the D'Amico tumor risk criteria?

PurposeTo evaluate the accuracy of a 3D-endorectal 1 mm-thick slices MRI acquisition for local staging of low, intermediate and high D'Amico risk prostate cancer (PCa).Materials and methods178 consecutive patients underwent a multiparametric MRI protocol prior to radical prostatectomy (RP). T2W images were acquired with the 3D sampling perfection with application optimized contrasts using different flip angle evolutions (SPACE) sequence (5 mn acquisition time). Direct and indirect MRI signs of extracapsular extension (ECE) were evaluated to predict the pT stage. The likelihood of SVI (seminal vesicle invasion) was also assessed.ResultsHistology showed ECE and SVI in 38 (21%) and 12 (7%) cases, respectively. MRI sensitivity and specificity to detect ECE were 55 and 96% if direct signs of ECE were used and 84 and 89% (p < 0.05), if both direct and indirect signs were combined. D'Amico criteria did not influence MRI performance. Sensitivity and specificity for SVI detection were 83% and 99%.Conclusions3D data sets acquired with the SPACE sequence provides a high accuracy for local staging of prostate cancer. The use of indirect signs of ECE may be recommended in low D'Amico risk tumors to optimise patient selection for active surveillance or focal therapy.