title: Can positron emission tomography improve the quality of care for head-and-neck cancer patients?
abstract: OBJECTIVE
  Fluoro-2-deoxy-d-glucose-positron emission tomography (FDG-PET) is a functional imaging modality that measures the relative uptake of 18FDG with PET. The purpose of this review is to assess the potential contribution of FDG-PET scans to the treatment of head-and-neck cancer patients.
  
  
  METHODS
  Data were assessed from the literature with attention to what additional information may be gained from the use of FDG-PET in four clinical settings: (1) detection of occult metastatic disease in the neck, (2) detection of occult primaries in patients with neck metastases, (3) detection of synchronous primaries or metastatic disease in the chest, and (4) detection of residual/recurrent locoregional disease.
  
  
  RESULTS
  Although the data are somewhat conflicting, FDG-PET appears to add little additional value to the physical examination and conventional imaging studies (supplemented by biopsy when appropriate) for the detection of subclinical nodal metastases, unknown primaries, or disease in the chest. However, FDG-PET scans are quite useful in differentiating residual/recurrent disease from treatment-induced normal tissue changes. A positive FDG-PET scan at 1 month after radiotherapy is highly indicative of the presence of residual disease, and a negative scan at 4 months after treatment is highly predictive of tumor eradication.
  
  
  CONCLUSIONS
  Large-scale studies using newer generation equipment and more defined methods are needed to more rigorously assess the potential of FDG-PET in the detection of subclinical primary or simultaneous secondary tumors and of nodal or systemic spread. Currently, however, FDG-PET can contribute to the detection of residual/early recurrent tumors, leading to the timely institution of salvage therapy or the prevention of unnecessary biopsies of irradiated tissues, which may aggravate injury.
authors.affiliation: Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA. nschecht@mdanderson.org
authors.forename: N R
authors.initials: NR
authors.lastname: Schechter
authors.forename: A M
authors.initials: AM
authors.lastname: Gillenwater
authors.forename: R M
authors.initials: RM
authors.lastname: Byers
authors.forename: A S
authors.initials: AS
authors.lastname: Garden
authors.forename: W H
authors.initials: WH
authors.lastname: Morrison
authors.forename: L N
authors.initials: LN
authors.lastname: Nguyen
authors.forename: D A
authors.initials: DA
authors.lastname: Podoloff
authors.forename: K K
authors.initials: KK
authors.lastname: Ang
mesh_terms: D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy; D006801:Humans; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging; D018365:Neoplasm, Residual; D009382:Neoplasms, Unknown Primary / Q000000981:diagnostic imaging; D019275:Radiopharmaceuticals; D014055:Tomography, Emission-Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18