Prospective comparison of CT and 18F-FDG PET/MRI in N and M staging of primary breast cancer patients: Initial results

PLoS One. 2021 Dec 2;16(12):e0260804. doi: 10.1371/journal.pone.0260804. eCollection 2021.

Abstract

Objectives: To compare the diagnostic accuracy of contrast-enhanced thoraco-abdominal computed tomography and whole-body 18F-FDG PET/MRI in N and M staging in newly diagnosed, histopathological proven breast cancer.

Material and methods: A total of 80 consecutive women with newly diagnosed and histopathologically confirmed breast cancer were enrolled in this prospective study. Following inclusion criteria had to be fulfilled: (1) newly diagnosed, treatment-naive T2-tumor or higher T-stage or (2) newly diagnosed, treatment-naive triple-negative tumor of every size or (3) newly diagnosed, treatment-naive tumor with molecular high risk (T1c, Ki67 >14%, HER2neu over-expression, G3). All patients underwent a thoraco-abdominal ceCT and a whole-body 18F-FDG PET/MRI. All datasets were evaluated by two experienced radiologists in hybrid imaging regarding suspect lesion count, localization, categorization and diagnostic confidence. Images were interpreted in random order with a reading gap of at least 4 weeks to avoid recognition bias. Histopathological results as well as follow-up imaging served as reference standard. Differences in staging accuracy were assessed using Mc Nemars chi2 test.

Results: CT rated the N stage correctly in 64 of 80 (80%, 95% CI:70.0-87.3) patients with a sensitivity of 61.5% (CI:45.9-75.1), a specificity of 97.6% (CI:87.4-99.6), a PPV of 96% (CI:80.5-99.3), and a NPV of 72.7% (CI:59.8-82.7). Compared to this, 18F-FDG PET/MRI determined the N stage correctly in 71 of 80 (88.75%, CI:80.0-94.0) patients with a sensitivity of 82.1% (CI:67.3-91.0), a specificity of 95.1% (CI:83.9-98.7), a PPV of 94.1% (CI:80.9-98.4) and a NPV of 84.8% (CI:71.8-92.4). Differences in sensitivities were statistically significant (difference 20.6%, CI:-0.02-40.9; p = 0.008). Distant metastases were present in 7/80 patients (8.75%). 18 F-FDG PET/MRI detected all of the histopathological proven metastases without any false-positive findings, while 3 patients with bone metastases were missed in CT (sensitivity 57.1%, specificity 95.9%). Additionally, CT presented false-positive findings in 3 patients.

Conclusion: 18F-FDG PET/MRI has a high diagnostic potential and outperforms CT in assessing the N and M stage in patients with primary breast cancer.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Breast Neoplasms / diagnostic imaging
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology*
  • Female
  • Fluorodeoxyglucose F18 / metabolism*
  • Humans
  • Magnetic Resonance Imaging / methods*
  • Middle Aged
  • Neoplasm Staging
  • Positron-Emission Tomography / methods*
  • Prospective Studies
  • ROC Curve
  • Radiopharmaceuticals / metabolism
  • Tomography, X-Ray Computed / methods*

Substances

  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18

Grants and funding

The study is funded by Deutsche Forschungsgemeinschaft (DFG), the German Research Foundation (BU3075/2-1). The funding foundation was not involved in trial design, patient recruitment, data collection, analysis, interpretation or presentation, writing or editing of the reports, or the decision to submit for publication. The corresponding author had full access to all data in the study and had all responsibility for the decision to submit for publication. Christian Buchbender was the main recipient.