Magnetic Resonance Imaging-Determined Tumor Contact Area to predict Pathological Extra Prostatic Extension in Clinical T2 Prostate Cancer.

Objectives : To assess the valuability of MRI-determined tumor contact area as a predictive factor of pathological extraprostatic extension in cT2N0M0 prostate cancer. Methods : Seventy-two cT2N0M0 prostate cancer patients were retrospectively analyzed who received multiparametric MRI followed by robot-assisted laparoscopic prostatectomy as a primary treatment between February 2014 and April 2021. Patients were excluded whose index lesion did not match between MRI and pathological specimen. MRI-determined tumor contact area was approximated as an ellipse shape, and calculated by two different formula: MRI-TCA1 was calculated using both tumor contact length in axial plane and longer tumor contact length in sagittal or coronal plane. MRI-TCA2 was calculated using tumor contact length in axial plane and tumor thickness in volume data. Results : Sixteen patients were pathologically extraprostatic extension positive. Age, initial PSA, preoperative T classification, Gleason score and resection margin status were no significance between extraprostatic extension positive and negative. MRI-determined tumor contact length, MRI-TCA1 and MRI-TCA2 were significantly greater in extraprostatic extension positive than in negative (p<0.0001, p<0.0001 and p=0.0026, respectively). Conclusions : MRI-determined tumor contact area was clinically available parameter to predict extraprostatic extension in cT2N0M0 prostate cancer.