¹⁸F-FDG PET/MRI Primary Staging of Cervical Cancer: A Pilot Study with PET/CT Comparison

We report our PET/MRI experience from a pilot study that compared the diagnostic performance of ¹⁸F-FDG PET/MRI versus PET/CT in staging of cervical cancer. Methods: Six adults with newly diagnosed cervical cancer underwent a single ¹⁸F-FDG injection with a dual-imaging protocol: standard-of-care PET/CT followed by research PET/MRI. The diagnostic interpretation and SUV_max for the 2 modalities were compared. Results: Both modalities detected all primary tumors (median size, 3.9 cm) and all 4 metastases present in 2 of the 6 patients (median size, 0.9 cm). PET/MRI provided greater diagnostic confidence than PET/CT and upstaged the disease in 4 patients. On the basis of the imaging findings alone, the additional information from PET/MRI would have led to a change in clinical management in 3 of 6 patients. The primary lesion showed a median SUV of 12.8 on PET/CT and 18.2 on PET/MRI (P = 0.03). SUVs, however, correlated strongly between the 2 modalities (ρ = 0.96, P < 0.001). Conclusion: Our pilot study supports the notion that PET/MRI has the potential to impact clinical decisions and treatment strategies in women with cervical cancer. Further studies are, however, warranted to define the value that PET/MRI adds to PET/CT.