title: Prospective, longitudinal electroglottographic study of voice recovery following accelerated hypofractionated radiotherapy for T1/T2 larynx cancer.
abstract: OBJECTIVE
  To measure voice outcomes following accelerated hypofractionated radiotherapy for larynx cancer.
  
  
  METHODS
  Twenty-five patients with T1/T2 glottic cancer underwent serial electroglottographic and acoustic analysis (sustained vowel/i/ and connected speech) before radiotherapy and 1, 6 and 12 months post-treatment. Twenty-five normal subjects served as a reference control population.
  
  
  RESULTS
  Pre-treatment measures were significantly worse for larynx cancer patients. Median jitter (0.23% vs 0.97%, p=0.001) and shimmer (0.62dB vs 0.98dB, p=0.05) and differences in data ranges reflected greater frequency and amplitude perturbation in the larynx cancer patients. Pre-treatment Mean Phonation Time (MPT) was significantly reduced (21s vs 14.8s, p=0.002) in larynx cancer patients. There was a trend towards improvement of jitter, shimmer and normalized noise energy at 12 months post-treatment. MPT improved but remained significantly worse than for normal subjects (21s vs 16.4s, p=0.013). Average fundamental frequency resembled normal subjects, including improvement of the measured range (91.4-244.6Hz in controls vs 100-201Hz in post-treatment larynx cancer patients).
  
  
  CONCLUSIONS
  This non-invasive technique effectively measures post-treatment vocal function in larynx cancer patients. This study demonstrated improvement of many key parameters that influence voice function over 12 months after radiotherapy.
authors.affiliation: Head and Neck Unit, Royal Marsden Hospital, London, UK.
authors.forename: Rehan
authors.initials: R
authors.lastname: Kazi
authors.forename: Ramachandran
authors.initials: R
authors.lastname: Venkitaraman
authors.forename: Catherine
authors.initials: C
authors.lastname: Johnson
authors.forename: Vyas
authors.initials: V
authors.lastname: Prasad
authors.forename: Peter
authors.initials: P
authors.lastname: Clarke
authors.forename: Kate
authors.initials: K
authors.lastname: Newbold
authors.forename: Peter
authors.initials: P
authors.lastname: Rhys-Evans
authors.forename: Christopher
authors.initials: C
authors.lastname: Nutting
authors.forename: Kevin
authors.initials: K
authors.lastname: Harrington
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D019583:Dose Fractionation, Radiation; D017097:Electric Impedance; D005260:Female; D006801:Humans; D007822:Laryngeal Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D020127:Recovery of Function; D018709:Statistics, Nonparametric; D014833:Voice Quality / Q000528:radiation effects*