18F-FDG PET/CT and PET/MRI perform equally well in cancer patients: Evidence from studies in more than 2300 patients.

(18)F-FDG-PET/CT has become the reference standard in oncologic imaging against which the performance of other imaging modalities is measured. The promise of PET/MRI includes multi-parametric imaging to further improve diagnosis and phenotyping of cancer.

Rather than focusing on these capabilities many investigators have however examined whether (18)F-FDG-PET combined with mostly anatomic MRI improves cancer staging and restaging. Following a description of PET/MRI designs, and a discussion of technical and operational issues we review the available literature to determine whether cancer assessments are improved with PET/MRI. The available data show that PET/MRI is feasible and performs equally well as PET/CT in most cancers. Diagnostic advantages may be achievable in prostate cancer and in bone metastases while disadvantages may exist in lung nodule assessments. We conclude that (18)F-FDG PET/MRI and PET/CT provide comparable diagnostic information when MRI is simply used to provide the anatomical framework. Thus, PET/MRI could be used in lieu of PET/CT if this approach becomes economically viable and if reasonable workflows can be established. Future studies should explore the multi-parametric potential of MRI.

Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2016 Jan 07 [Epub ahead of print]

Claudio Spick, Ken Herrmann, Johannes Czernin

UCLA School of Medicine, United States. , UCLA School of Medicine, United States. , UCLA School of Medicine, United States.