Whole-body PET/MRI in oncology: current status and clinical applications

Abstract

In oncology, diagnostic imaging plays a major role in staging, therapy assessment and in the evaluation of tumor biology. Multimodality imaging, and more specifically positron emission tomography/computed tomography (PET/CT), has matured into an important imaging tool. The recent introduction of the integrated whole-body PET/magnetic resonance imaging (MRI) represents the addition of a promising methodology in clinical practice. Combining the metabolic data of PET with the anatomical and functional information provided by MRI and fMRI may further improve the diagnostic value of each method alone. Although the literature is still limited, data indicate a potential advantage of PET/MRI over PET/CT in all the indications where MRI is superior to CT, as well as in the evaluation of tumor biology. Integrated PET/MRI might be performed in addition to the existing imaging modality in specific regions. Moreover, integrated PET/MRI is an alternative to PET/CT when a low radiation dose is required, i.e. in children and in repeated imaging. In the rapidly evolving field of diagnostic imaging, the role of a new modality should be accurately evaluated. Further studies are needed to test the diagnostic accuracy of PET/MRI in different oncology indications. Whether PET/MRI will replace PET/CT or be a complementary methodology and whether it represents true diagnostic progress remains to be evaluated, also taking into account economic considerations.