title: Head and neck cancers: post-therapy changes in muscles with FDG PET-CT.
abstract: BACKGROUND
  FDG PET-CT plays a critical role in the management of head and neck cancer patients. After therapy, many patterns of altered physiologic FDG uptake have been recognized. In our institution, we noticed patterns of head and neck muscle uptake that were unique in the post-therapy scans of head and neck cancer patients.
  
  
  METHODS
  A total of 32 patients with head and neck cancers who had both pretherapy and posttherapy FDG PET-CT scans were retrospectively analyzed. Regional anatomic muscle groups that had increased PET uptake on either pretherapy or post-therapy scans were identified.
  
  
  RESULTS
  On the pretherapy scans, the majority of patients (24/32 patients) did not have increased PET activity in the predefined muscle groups. On the post-therapy scans, the majority of patients (25/32 patients) demonstrated increased uptake in at least 1 head and neck muscle group, with an average of 3 muscle groups per patient. The muscle groups with the greatest frequencies were the prevertebral (50%), the accessory neck (47%), the posterior paravertebral (47%), and the scalene muscles (38%). Relative to pretherapy scans, the mean intensity of the post-therapy elevations corresponded to greater SUVs.
  
  
  CONCLUSIONS
  FDG PET-CT scan commonly depicts an elevated FDG muscle uptake in all regional anatomic muscle groups in the post-therapy head and neck cancer patient. This uptake should be considered as a consequence of treatment and perhaps changes in altered biomechanics, and not be confused with residual or recurrent neoplastic activity.
authors.affiliation: Department of Radiology, Stony Brook University Medical Center, Stony Brook, NY 11794-8460, USA. robert.matthews@stonybrook.edu
authors.forename: Robert
authors.initials: R
authors.lastname: Matthews
authors.forename: Prashant
authors.initials: P
authors.lastname: Shrestha
authors.forename: Dinko
authors.initials: D
authors.lastname: Franceschi
authors.forename: Nand
authors.initials: N
authors.lastname: Relan
authors.forename: Electra
authors.initials: E
authors.lastname: Kaloudis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009334:Neck Muscles / Q000000981:diagnostic imaging* / Q000378:metabolism; D049268:Positron-Emission Tomography; D011859:Radiography; D014055:Tomography, Emission-Computed
chemical_list: D019788:Fluorodeoxyglucose F18