title: Comparison of physical examination and fluorodeoxyglucose positron emission tomography/computed tomography 4-6 months after radiotherapy to assess residual head-and-neck cancer.
abstract: OBJECTIVE
  To retrospectively compare fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and physical examination 4-6 months after radiotherapy for assessing residual head-and-neck cancer (HNC).
  
  
  METHODS
  From July 2002 through March 2006, 52 HNC patients underwent definitive radiotherapy or chemoradiotherapy. Categoric assessments of residual tumor by PET/CT and physical examination 4-6 months after therapy were correlated and compared with clinical outcomes. Pretreatment data, including tumor stage and primary site standardized uptake value, were also gathered retrospectively and correlated with clinical outcomes. Median follow-up time was 58 months.
  
  
  RESULTS
  Twenty-one patients had either locoregionally "positive" (17 of 21) or "equivocal" (4 of 21) PET/CT scans, whereas 31 patients had locoregionally negative scans. Four patients failed treatment and had biopsy-confirmed residual or recurrent local disease. All patients, including patients with locally suspicious scans or examinations who refused biopsies, were followed clinically for a minimum of 29 months after therapy, with no other cases of treatment failure detected during this time. No patient had residual nodal disease after therapy. Sensitivities of PET/CT vs. physical examination for early detection of treatment failure were 100% vs. 50%, whereas the specificities of the two modalities were 64.6% vs. 89.6%, respectively. Higher initial T stage and American Joint Commission on Cancer stage correlated with increased incidence of positive/equivocal PET/CT results and treatment failure. Maximal standardized uptake value was not predictive of any clinical outcome.
  
  
  CONCLUSIONS
  A negative result on PET/CT obtained 4-6 months after radiotherapy is highly sensitive and correlates with successful locoregional control. Patients with negative scans may reasonably be spared invasive diagnostic procedures, such as biopsy and neck dissection, unless recurrent disease is suspected on clinical grounds. Close follow-up is prudent for HNC patients with abnormal findings on posttherapy PET/CT scan.
authors.affiliation: Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI 53045, USA.
authors.forename: M Tracy
authors.initials: MT
authors.lastname: Zundel
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Michel
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Schultz
authors.forename: Mohit
authors.initials: M
authors.lastname: Maheshwari
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Wong
authors.forename: Bruce H
authors.initials: BH
authors.lastname: Campbell
authors.forename: Becky L
authors.initials: BL
authors.lastname: Massey
authors.forename: Joel
authors.initials: J
authors.lastname: Blumin
authors.forename: J Frank
authors.initials: JF
authors.lastname: Wilson
authors.forename: Dian
authors.initials: D
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059248:Chemoradiotherapy; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000188:drug therapy / Q000532:radiotherapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D018365:Neoplasm, Residual; D010808:Physical Examination; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D017211:Treatment Failure; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18