Comparison of nodal staging between CT, MRI, and [18F]-FDG PET/MRI in patients with newly diagnosed breast cancer

Eur J Nucl Med Mol Imaging. 2022 Feb;49(3):992-1001. doi: 10.1007/s00259-021-05502-0. Epub 2021 Sep 3.

Abstract

Purpose: To compare CT, MRI, and [18F]-fluorodeoxyglucose positron emission tomography ([18F]-FDG PET/MRI) for nodal status, regarding quantity and location of metastatic locoregional lymph nodes in patients with newly diagnosed breast cancer.

Materials and methods: One hundred eighty-two patients (mean age 52.7 ± 11.9 years) were included in this prospective double-center study. Patients underwent dedicated contrast-enhanced chest/abdomen/pelvis computed tomography (CT) and whole-body ([18F]-FDG PET/) magnet resonance imaging (MRI). Thoracal datasets were evaluated separately regarding quantity, lymph node station (axillary levels I-III, supraclavicular, internal mammary chain), and lesion character (benign vs. malign). Histopathology served as reference standard for patient-based analysis. Patient-based and lesion-based analyses were compared by a McNemar test. Sensitivity, specificity, positive and negative predictive values, and accuracy were assessed for all three imaging modalities.

Results: On a patient-based analysis, PET/MRI correctly detected significantly more nodal positive patients than MRI (p < 0.0001) and CT (p < 0.0001). No statistically significant difference was seen between CT and MRI. PET/MRI detected 193 lesions in 75 patients (41.2%), while MRI detected 123 lesions in 56 patients (30.8%) and CT detected 104 lesions in 50 patients, respectively. Differences were statistically significant on a lesion-based analysis (PET/MRI vs. MRI, p < 0.0001; PET/MRI vs. CT, p < 0.0001; MRI vs. CT, p = 0.015). Subgroup analysis for different lymph node stations showed that PET/MRI detected significantly more lymph node metastases than MRI and CT in each location (axillary levels I-III, supraclavicular, mammary internal chain). MRI was superior to CT only in axillary level I (p = 0.0291).

Conclusion: [18F]-FDG PET/MRI outperforms CT or MRI in detecting nodal involvement on a patient-based analysis and on a lesion-based analysis. Furthermore, PET/MRI was superior to CT or MRI in detecting lymph node metastases in all lymph node stations. Of all the tested imaging modalities, PET/MRI showed the highest sensitivity, whereas CT showed the lowest sensitivity, but was most specific.

Keywords: Breast cancer; Nodal staging; PET/MR.

MeSH terms

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

Substances

  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18