title: Head and neck tumors: imaging recurrent tumor and post-therapeutic changes with CT and MRI.
abstract: OBJECTIVE
  To evaluate criteria for detection of tumor recurrence and post-treatment changes in patients with head and neck malignancies in computed tomography (CT) and magnetic resonance imaging (MRI).
  
  
  METHODS
  Thirty-nine patients with head and neck carcinoma receiving radiochemotherapy were examined before, during and after therapy with MRI. Changes in signal intensity were correlated to histology or clinical course. Three hundred and thirty-one patients with head and neck malignancies were examined with CT after therapy. CT diagnoses were correlated with histology or clinical course.
  
  
  RESULTS
  Main criteria for recurrent/residual tumor in MRI was infiltrative mass with high signal intensity in T2-weighted images and enhancement 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 therapy 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 sensitivity of 86% and a specificity of 80%.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Institute of Diagnostic Radiology, Friedrich-Alexander-University Erlangen-Nürnberg, Maximiliansplatz 1, 91054, Erlangen, Germany. lell@idr.med.uni-erlangen.de
authors.forename: M
authors.initials: M
authors.lastname: Lell
authors.forename: U
authors.initials: U
authors.lastname: Baum
authors.forename: H
authors.initials: H
authors.lastname: Greess
authors.forename: A
authors.initials: A
authors.lastname: Nömayr
authors.forename: E
authors.initials: E
authors.lastname: Nkenke
authors.forename: M
authors.initials: M
authors.lastname: Koester
authors.forename: M
authors.initials: M
authors.lastname: Lenz
authors.forename: W
authors.initials: W
authors.lastname: Bautz
mesh_terms: D003131:Combined Modality Therapy; D003287:Contrast Media; D005500:Follow-Up Studies; D019786:Gadolinium DTPA; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000628:therapy; D006801:Humans; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000628:therapy; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA