Head and neck tumors: imaging recurrent tumor and post-therapeutic changeswith CT and MRI

Objective. To evaluate criteria for detection of tumor recurrence and post- treatment changes in patients with head and neck malignancies in computed t omography (CT) and magnetic resonance imaging (MRI). Methods and materials: Thirty-nine patients with head and neck carcinoma receiving radiochemother apy were examined before, during and after therapy with MRI. Changes in sig nal intensity were correlated to histology or clinical course. Three hundre d and thirty-one patients with head and neck malignancies. were examined wi th CT after therapy. CT diagnoses were correlated with histology or clinica l course. Results: Main criteria for recurrent/residual tumor in MRI was in filtrative mass with high signal intensity in T2-weighted images and enhanc ement after Gd-DTPA in T1-weighted images. Radiation-induced changes led to false positive diagnosis in 46% in the interval up to 3 months after thera py and in 58% in the interval 3-6 months after therapy. The combination of a circumscribed, infiltrative mass with contrast enhancement in CT had a se nsitivity of 86% and a specificity of 80%. Conclusion: CT could accurately demonstrate postoperative changes and tumor recurrence. MRI had advantages in differentiation of tumor and scar, but edema after radiation therapy can spoil diagnosis. (C) 2000 Elsevier Science Ireland Ltd. All rights reserve d.