Head and Neck Cancer: Comparative Evaluation by CT, MRI and FDG-PET

Purpose : To investigate the diagnostic accuracy of head and neck cancer, lymph node metastasis, and local tumor recurrence, by FDG-PET compared with CT and MRI, and to validate the results with the histopathological data. Patients and Methods : Forty one patients with head and neck cancer were enrolled. Our patients presented for primary staging of head and neck cancer (n =23) or monitoring after therapy (n = 18). The three imaging modalities (FDG-PET, MRI and CT) were compared. Results : Overall 82 head and neck regions were analyzed for detection of malignancy (for primary tumors ; n = 23, for lymph node metastasis ; n = 41, for local tumor recurrence after therapy ; n = 18). The overall sensitivity and specificity were ; CT 88.9% and 89.2% (95% CI ; 80.2-94.9%, r = 0.7791, P < 0.0001), MRI 88.9% and 91.9% (95% CI ; 81.9-95.8%, r = 0.8049, P < 0.0001), and FDG-PET 97.78% and 86.49% (95% CI ; 84-96.9%, r = 0.8551, P < 0.0001). Only FDG-PET by its unique advantage as a whole-body examination could detect distant metastases in 4/41 (9.8 %) patients, all outside the head and neck region (liver, lung, paraortic lymph nodes, and bone metastases), and synchronous breast cancer in 1/41 (2.4 %) patient. Conclusion : Compared with CT and MRI, FDG-PET was found to have the highest sensitivity with lower specificity than CT and MRI. Moreover, the whole-body FDG-PET imaging proves useful tool for detection of distant metastasis and synchronous tumors.