Diffusion-weighted MRI and 18F-FDG-PET/CT imaging: competition or synergy as diagnostic methods to manage sarcoma of the uterus? A systematic review of the literature.

Aim: To evaluate the diagnostic performance of fluorine-18-fluorodeoxyglucose PET/computed tomography (F-FDG-PET/CT) and MRI with diffusion-weighted images (DWI) in uterine sarcomas (US).

Patients And Methods: A systematic review was performed on Medline, ISI web of knowledge, and Scopus databases for studies reporting the diagnostic performance of F-FDG-PET/CT and DWI-MRI in US published up to 15 February 2016. Exclusion criteria were articles with fewer than five cases of US, without DWI-MRI, and previous series of patients from the same researcher team.

Results: Seven studies were selected for DWI-MRI and 11 for F-FDG-PET/CT. DWI-MRI was used only to characterize uterine tumors, and showed a good sensitivity but a low specificity. The apparent diffusion coefficient value seems to be the most discriminant between benign and malignant lesion. No data were available on staging and restaging.F-FDG-PET/CT improved patients' management when used for characterization, staging, and restaging because of its quite good accuracy. To date, few data exist on the prognostic role of F-FDG-PET/CT. Well-designed multicenter prospective trials are needed to establish definitively the exact role of imaging in the management of US.

Conclusion: Both DWI-MRI and F-FDG-PET/CT have their own advantages, and should be performed in a 'one stop shop' scan in the near future by PET/MRI engines.