Evaluation of PET and MR datasets in integrated 18F-FDG PET/MRI: A comparison of different MR sequences for whole-body restaging of breast cancer patients

Eur J Radiol. 2017 Apr:89:14-19. doi: 10.1016/j.ejrad.2016.12.019. Epub 2017 Jan 22.

Abstract

Objectives: To investigate the diagnostic value of different MR sequences and 18F-FDG PET data for whole-body restaging of breast cancer patients utilizing PET/MRI.

Methods: A total of 36 patients with suspected tumor recurrence of breast cancer based on clinical follow-up or abnormal findings in follow-up examinations (e.g. CT, MRI) were prospectively enrolled in this study. All patients underwent a PET/CT and subsequently an additional PET/MR scan. Two readers were instructed to identify the occurrence of a tumor relapse in subsequent MR and PET/MR readings, utilizing different MR sequence constellations for each session. The diagnostic confidence for the determination of a malignant or benign lesion was qualitatively rated (3-point ordinal scale) for each lesion in the different reading sessions and the lesion conspicuity (4-point ordinal scale) for the three different MR sequences was additionally evaluated.

Results: Tumor recurrence was present in 25/36 (69%) patients. All three PET/MRI readings showed a significantly higher accuracy as well as higher confidence levels for the detection of recurrent breast cancer lesions when compared to MRI alone (p<0.05). Furthermore, all three PET/MR sequence constellations showed comparable diagnostic accuracy for the identification of a breast cancer recurrence (p>0.05), yet the highest confidence levels were obtained, when all three MR sequences were used for image interpretation. Moreover, contrast-enhanced T1-weighted VIBE imaging showed significantly higher values for the delineation of malignant and benign lesions when compared to T2w HASTE and diffusion-weighted imaging.

Conclusion: Integrated PET/MRI provides superior restaging of breast cancer patients over MRI alone. Facing the need for appropriate and efficient whole-body PET/MR protocols, our results show the feasibility of fast and morphologically adequate PET/MR protocols. However, considering an equivalent accuracy for the detection of breast cancer recurrences in the three PET/MR readings, the application of contrast-agent and the inclusion of DWI in the study protocol seems to be debatable.

Keywords: 18F-FDG; Breast cancer; PET/MRI; Protocol optimization; Whole-body restaging.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Breast / diagnostic imaging
  • Breast / pathology
  • Breast Neoplasms / diagnostic imaging*
  • Breast Neoplasms / pathology*
  • Female
  • Fluorodeoxyglucose F18*
  • Humans
  • Magnetic Resonance Imaging / methods*
  • Middle Aged
  • Multimodal Imaging / methods
  • Neoplasm Recurrence, Local / diagnostic imaging*
  • Neoplasm Recurrence, Local / pathology
  • Neoplasm Staging
  • Positron-Emission Tomography / methods*
  • Radiopharmaceuticals
  • Reproducibility of Results
  • Whole Body Imaging / methods*

Substances

  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18