title: Incidental focal FDG uptake in the parotid glands on PET/CT in patients with head and neck malignancy.
abstract: OBJECTIVE
  To evaluate the prevalence and clinical significance of focal parotid lesions identified by (18)F- FDG PET/CT in patients with nonparotid head and neck malignancies.
  
  
  METHODS
  From 3,638 PET/CT examinations using (18)F-FDG conducted on 1,342 patients with nonparotid head and neck malignancies, we retrospectively identified patients showing incidental focal FDG uptake in the parotid glands. The diagnosis of parotid lesions was confirmed histopathologically or on imaging follow-up. Patient demographics, clinical features, maximum standardized uptake value (SUV(max)) on PET images, size and attenuation on corresponding contrast-enhanced CT images were assessed and correlated with the final diagnosis.
  
  
  RESULTS
  The prevalence of incidental focal parotid FDG uptake on PET/CT was 2.1% (95% CI 1.4 - 3.0%). Among 21 patients with focal parotid lesions confirmed histologically or on imaging follow-up, 7 (33.3%) had malignant lesions (all metastases) and 14 (66.7%) had benign lesions (four pleomorphic adenomas, two Warthin's tumours, one benign lymph node, one granulomatous lesion, six lesions without histopathological confirmation). There were no significant differences in age, sex, SUV(max) or CT findings between patients with benign and those with malignant lesions.
  
  
  CONCLUSIONS
  Focal parotid FDG uptake on PET/CT in patients with head and neck malignancy warrants further investigations to ensure adequate therapy for incidental parotid lesions.
  
  
  CONCLUSIONS
  • The prevalence of parotid incidentaloma on PET in head and neck malignancy was 2.1% • The malignancy rate of incidental focal parotid FDG uptake was 33.3% • SUV max could not reliably differentiate malignant from benign incidental parotid lesions.
authors.affiliation: Department of Radiology, Kangdong Seong-Sim Hospital, Hallym University College of Medicine, 150, Seongan-ro Gangdong-Gu, Seoul, 134-701, Korea.
authors.forename: Young Lan
authors.initials: YL
authors.lastname: Seo
authors.forename: Dae Young
authors.initials: DY
authors.lastname: Yoon
authors.forename: Sora
authors.initials: S
authors.lastname: Baek
authors.forename: Kyoung Ja
authors.initials: KJ
authors.lastname: Lim
authors.forename: Eun Joo
authors.initials: EJ
authors.lastname: Yun
authors.forename: Young Kwon
authors.initials: YK
authors.lastname: Cho
authors.forename: Woo Jin
authors.initials: WJ
authors.lastname: Bae
authors.forename: Eun Jae
authors.initials: EJ
authors.lastname: Chung
authors.forename: Kee Hwan
authors.initials: KH
authors.lastname: Kwon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D006801:Humans; D033162:Incidental Findings; D008297:Male; D008875:Middle Aged; D010306:Parotid Gland / Q000000981:diagnostic imaging / Q000378:metabolism*; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18