The Diagnostic Value of Computed Tomography in Determining Invasion to Carotid Arteries by Head and Neck Malignant Tumors

Background/ Awareness of invasion to the walls of the carotid arteries by malignant tumors, either tumoral mass or metastatic lymph nodes, is of great clinical importance before surgery and can change the management strategy. This study was conducted to assess the diagnostic value of computed tomography (CT) in determining invasion to carotid artery (CA) by oromaxillofacial and neck malignant tumors.Patients and CT with contrast was performed in 40 patients who has had oromaxillofacial and neck malignant tumors before surgical intervention. Abnormal CT findings in our patients were categorized into 6 types: I) tumor encasement of carotid arteries ≥270 degrees; II) tumor encasement of carotid arteries ≥180 degrees; III) compression and deformation of CA; IV) displacement of CA; V) ill-defined CA wall; and VI) the segmental deletion of fat or fascial planes between tumor and CA. The CT appearances of all tumors were prospectively compared with surgical findings. Abnormal CT findings in our patients included 6 with form I; 17 with type II; 2 with type III; 8 with type IV; 7 with type V; and 33 with type VI. Surgical findings showed that the tumors invaded CA vessels in 13 of 40 patients. The sensitivity, specificity, accuracy and positive and negative likelihood ratio values with 95% confidence interval for type I were 0.31, 0.93, 0.7, 4.15 and 1.3; for type II were 0.62, 0.67, 0.65, 1.8 and 1.7; for type III were 0, 0.93, 0. 63, 0 and 0.93; for type IV were 0.07, 0.74, 0.53, 0.3 and 0.8; for type V were 0.39, 0. 93, 0.69, 5.2 and 1.6; and for type VI were 1, 0.26, 0.50 and 1.35, respectively. Though many CT findings are of value in determining of CA invasion by head and neck tumors, our study demonstrated that encasement ≥270 degree (type I), ill-defined wall of the artery (type V) and segmental deletion of fat or fascial planes between tumor and CA (type VI) are valuable in determining CA invasion by tumors. However, CT is not a definite way for the diagnosis of CA in-volvement by malignant tumoral lesions.