title: Reevaluation of FDG-PET/CT in patients with hoarseness caused by vocal cord palsy.
abstract: OBJECTIVE
  Vocal cord palsy (VCP) is a potential cause of hoarseness that results in decreasing mobility of the vocal cord. VCP can arise from a variety of causes; so, systematic screening is warranted for the management of patients with VCP. Asymmetrical fluorodeoxyglucose (FDG) uptake in vocal cords is a well-known feature in patients with VCP, but no detailed analysis has been performed. This study aimed at reevaluating the (18)F-FDG positron emission tomography/computed tomography (PET/CT) for patients with VCP.
  
  
  METHODS
  We retrospectively surveyed the results of FDG-PET/CT for 59 patients with VCP, compared to laryngoscopic findings. Quantitative analysis was performed using maximum standardized uptake value (SUVmax), and regions of interest were drawn over bilateral vocal cords as confirmed from the CT portion of PET/CT. Patients were divided into 3 groups: Group 1 (n = 14), in which VCP was caused by the lesion of the laryngeal area; Group 2 (n = 40), in which VCP was caused by the lesion on the root of the recurrent laryngeal nerve; and Group 3 (n = 5), in which VCP was caused by the lesion from the vagal center to the proximal vagus nerve.
  
  
  RESULTS
  For Group 1, higher FDG uptake in the paralyzed vocal cord was seen in 86 % of patients (mean SUVmax 8.1 ± 5.3 vs. 2.3 ± 0.4, paralyzed vs. non-paralyzed, respectively; P < 0.002). The sensitivity of FDG-PET/CT for indicating the lesion causing VCP was 79 % for Group 1. Group 2 showed dominant FDG uptake in the non-paralyzed vocal cord (mean SUVmax 2.1 ± 0.9 vs. 1.5 ± 0.4, non-paralyzed vs. paralyzed, respectively; P < 0.001). The sensitivity of FDG-PET/CT for indicating the lesion causing VCP was 93 % for Group 2. Group 3 showed no statistically significant difference in FDG accumulation between non-paralyzed and paralyzed vocal cords (mean SUVmax 1.8 ± 0.3 vs. 1.7 ± 0.3, non- paralyzed vs. paralyzed, respectively; P = 0.30). The sensitivity of FDG-PET/CT for indicating the lesion causing VCP was 60 % for Group 3.
  
  
  CONCLUSIONS
  FDG accumulation in the vocal cords is dependent on the lesion site causing VCP. In addition, FDG-PET/CT can contribute to identification of the lesion responsible for inducing VCP.
authors.affiliation: Division of Nuclear Medicine, Department of Radiology, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjyuku-ku, Tokyo, 162-8655, Japan, ryogominamimoto@yahoo.co.jp.
authors.forename: Ryogo
authors.initials: R
authors.lastname: Minamimoto
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kubota
authors.forename: Miyako
authors.initials: M
authors.lastname: Morooka
authors.forename: Kimiteru
authors.initials: K
authors.lastname: Ito
authors.forename: Takuya
authors.initials: T
authors.lastname: Mitsumoto
authors.forename: Momoko
authors.initials: M
authors.lastname: Okasaki
authors.forename: Takuro
authors.initials: T
authors.lastname: Shimbo
authors.forename: Niro
authors.initials: N
authors.lastname: Tayama
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001692:Biological Transport; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D006685:Hoarseness / Q000175:diagnosis* / Q000209:etiology* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014826:Vocal Cord Paralysis / Q000150:complications*
chemical_list: D019788:Fluorodeoxyglucose F18