Limitations of abdominopelvic CT and multiparametric MR imaging for detection of lymph node metastases prior to radical prostatectomy

World J Urol. 2021 Mar;39(3):779-785. doi: 10.1007/s00345-020-03227-7. Epub 2020 May 2.


Purpose: To investigate the performance of pre-surgery CT and multiparametric MRI (mpMRI) to identify lymph node (LN) metastases in the Michigan Urological Surgery Improvement Collaborative (MUSIC). Abdominopelvic CT and mpMRI are commonly used for intermediate- and high-risk prostate cancer (PCa) staging.

Methods: Retrospective analysis of the MUSIC registry identified patients undergoing robot-assisted radical prostatectomy (RP) between 3/2012 and 7/2018. Patients were classified according to pre-surgery imaging modality. Primary outcomes were operating characteristics of CT and mpMRI for detection of pathologic LN involvement (pN1).

Results: A total of 10,250 patients underwent RP and 3924 patients (38.3%) underwent CT and/or mpMRI prior to surgery. Suspicion for LN involvement was identified on 2.3% CT and 1.9% mpMRI. Overall, 391 patients were pN1(3.8%), including 0.1% low-, 2.1% intermediate-, and 10.9% high-risk PCa patients. Of 235 pN1 patients that underwent CT prior, far more had negative (91.1%) than positive (8.9%) findings, yielding sensitivity: 8.9%, specificity: 98.3%, negative predictive value (NPV): 92.1%, and positive predictive value (PPV): 32.3% for CT with regard to LN metastases. Similarly, more patients with pN1 disease had negative mpMRI (81.0%) then suspicious or indeterminate MRI (19.0%), yielding sensitivity: 19.0%, specificity: 97.3%, NPV: 95.9%, and PPV: 26.7%.

Conclusions: Abdominopelvic CT and mpMRI have clear limitations in identifying LN metastases. Additional clinicopathologic features should be considered when making management decisions, as 2.1% and 10.9% with intermediate-and high-risk cancer had metastatic LNs. The majority of pN1 patients had a negative CT or a negative/indeterminate mpMRI prior to RP. Pelvic LN dissection should be performed in RP patients with intermediate- or high-risk PCa, independent of preoperative imaging results.

Keywords: Computed tomography; Imaging; Lymph node; Magnetic resonance imaging; Pelvic lymph node dissection; Prostate cancer.

MeSH terms

  • Abdomen / diagnostic imaging
  • Aged
  • Humans
  • Lymphatic Metastasis / diagnostic imaging*
  • Male
  • Middle Aged
  • Multiparametric Magnetic Resonance Imaging*
  • Pelvis / diagnostic imaging
  • Preoperative Period
  • Prostatectomy / methods
  • Prostatic Neoplasms / diagnostic imaging*
  • Prostatic Neoplasms / pathology*
  • Prostatic Neoplasms / surgery
  • Retrospective Studies
  • Tomography, X-Ray Computed*