title: Non-neoplastic process after neck dissection demonstrated on enhanced CT in patients with head and neck cancer.
abstract: OBJECTIVE
  Head and neck radiologists should be familiar with typical post-therapeutic changes on enhanced CT after neck dissection because CT is widely used for the follow-up study in order to detect recurrent tumours at an early stage. The purpose of this study was to reveal post-therapeutic anatomical alterations and non-neoplastic processes demonstrated on enhanced CT.
  
  
  METHODS
  Radical neck dissections were performed in 39 necks and modified radical neck dissections were performed in 8 necks. Post-operative radiotherapy was performed on 21 patients. Follow-up CT, studies were made within a period of 24 months.
  
  
  RESULTS
  On enhanced CT, the densities of soft tissues replacing the resected structures were homogeneous in 44 necks and showed no contrast enhancement in 39 necks. During the 24 months after treatment, most of the soft tissues did not increase in size and the attenuation of the soft tissue remained unchanged. In 44 of 47 necks, lymphoedema (LE) was observed around the carotid artery at an early stage, and it converged into the space between internal carotid artery and external carotid artery gradually. In patients without post-operative radiotherapy, LE was observed around the carotid artery in 17 of 23 necks at 3 months after neck dissection and disappeared rapidly thereafter. In patients with post-operative radiotherapy, LE increased until 3 months after radiotherapy and decreased slowly thereafter.
  
  
  CONCLUSIONS
  This is the first report of enhanced CT evaluation of LE around the carotid artery after neck dissection probably exacerbated by irradiation. Clinicians should be aware of LE around the carotid artery in patients with post-operative radiotherapy because of the possible risk of neck cellulitis at least 1 year after treatment.
authors.affiliation: Division of Oral and Maxillofacial Radiology, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, Niigata City, Niigata, 951-8520, Japan. katsu@dent.niigata-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Katsura
authors.forename: T
authors.initials: T
authors.lastname: Hayashi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002342:Carotid Artery, External / Q000000981:diagnostic imaging / Q000528:radiation effects; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000528:radiation effects; D002481:Cellulitis / Q000000981:diagnostic imaging; D003287:Contrast Media; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D008209:Lymphedema / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000000981:diagnostic imaging* / Q000473:pathology / Q000528:radiation effects; D037981:Neck Dissection; D011856:Radiographic Image Enhancement / Q000379:methods*; D018714:Radiotherapy, Adjuvant; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media