title: Evaluation of chemotherapy response in patients with advanced head and neck cancer using [F-18]fluorodeoxyglucose positron emission tomography.
abstract: BACKGROUND
  [F-18]Fluorodeoxyglucose (FDG)-positron emission tomography (PET) can measure the metabolic activity of tissues; FDG-PET may be able to predict response to chemotherapy by identifying changes in tumor metabolism. Measurement of response to treatment may help improve survival in the management of advanced head and neck cancer. We evaluated this particular use of FDG-PET in patients participating in a neoadjuvant organ-preservation protocol using taxol and carboplatin and compared pathologic response after chemotherapy with changes in tumor metabolism measured by FDG-PET.
  
  
  METHODS
  Serial FDG-PET studies (n = 56) were performed in patients (n = 28) with stage III/IV head and neck cancer participating in a neoadjuvant organ-preservation protocol. The FDG-PET studies were performed before and after chemotherapy. All patients had tissue biopsies before and after chemotherapy. Patients were classified as pathologic complete response (PCR) or residual disease (RD) based on tissue biopsies. Visual analysis of PET scans was performed to identify patients with complete response by PET, and these findings were compared with pathology results. Metabolic changes were also evaluated using standardized uptake ratios (SUR) of FDG.
  
  
  RESULTS
  The sensitivity and specificity of PET for residual cancer after therapy was 90% (19/21) and 83% (5/6), respectively. Two patients had initially negative biopsies and positive PET studies for persistent disease. Pathology review and rebiospy led to confirmation of the PET results in these cases, giving a sensitivity of 90% for initial tissue biopsy.
  
  
  CONCLUSIONS
  In this preliminary analysis, FDG-PET was accurate in classifying response to chemotherapy in most patients. Fluorodeoxyglucose-PET may identify residual viable tumor when it is otherwise undetectable.
authors.affiliation: Department of Nuclear Medicine, St. Louis University Health Sciences Center, PET Imaging Facility, Missouri 63110-0250, USA.
authors.forename: V J
authors.initials: VJ
authors.lastname: Lowe
authors.forename: F R
authors.initials: FR
authors.lastname: Dunphy
authors.forename: M
authors.initials: M
authors.lastname: Varvares
authors.forename: H
authors.initials: H
authors.lastname: Kim
authors.forename: M
authors.initials: M
authors.lastname: Wittry
authors.forename: C H
authors.initials: CH
authors.lastname: Dunphy
authors.forename: T
authors.initials: T
authors.lastname: Dunleavy
authors.forename: E
authors.initials: E
authors.lastname: McDonough
authors.forename: J
authors.initials: J
authors.lastname: Minster
authors.forename: J W
authors.initials: JW
authors.lastname: Fletcher
authors.forename: J H
authors.initials: JH
authors.lastname: Boyd
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001706:Biopsy; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D014055:Tomography, Emission-Computed
chemical_list: D000970:Antineoplastic Agents; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18