title: Correlating computed tomography perfusion changes in the pharyngeal constrictor muscles during head-and-neck radiotherapy to dysphagia outcome.
abstract: OBJECTIVE
  To measure changes in perfusion of the pharyngeal constrictor muscles (PCM) using CT perfusion (CTP) imaging during a course of definitive radiotherapy (RT) in head-and-neck cancer (HNC) patients and correlate with dysphagia outcome after RT.
  
  
  METHODS
  Fifteen HNC patients underwent CTP imaging of the PCM at baseline and Weeks 2, 4, and 6 during RT and 6 weeks after RT. Blood flow and blood volume were measured in the PCM, and percentage change from baseline scan was determined. A single physician-based assessment of dysphagia was performed every 3 months after RT using the Common Terminology Criteria for Adverse Events, version 3.0 grading system.
  
  
  RESULTS
  With a median follow-up of 28 months (range, 6-44 months), Grade 3 dysphagia was present in 7 of 15 patients, and 8 patients experienced Grade 0-2 dysphagia. The CTP parameters at Week 2 of RT demonstrated an increase in mean PCM blood flow of 161.9% vs. 12.3% (p = 0.007) and an increase in mean PCM blood volume of 96.6% vs. 8.7% (p = 0.039) in patients with 6-month post-RT Grade 3 dysphagia and Grade 0-2 dysphagia, respectively. On multivariate analysis, when adjusting for smoking history, tumor volume, and baseline dysphagia status, an increase in blood flow in the second week of RT was significant for 3- and 6-month Grade 3 dysphagia (p < 0.05).
  
  
  CONCLUSIONS
  Perfusion changes in the PCM during Week 2 of RT in the PCM may predict the severity of dysphagia after HNC RT.
authors.affiliation: Department of Radiation Oncology, Boston Medical Center and Boston University School of Medicine, Boston, MA 02118, USA. mitruong@bu.edu
authors.forename: Minh Tam
authors.initials: MT
authors.lastname: Truong
authors.forename: Richard
authors.initials: R
authors.lastname: Lee
authors.forename: Naoko
authors.initials: N
authors.lastname: Saito
authors.forename: Muhammad M
authors.initials: MM
authors.lastname: Qureshi
authors.forename: Al
authors.initials: A
authors.lastname: Ozonoff
authors.forename: Paul B
authors.initials: PB
authors.lastname: Romesser
authors.forename: Jimmy
authors.initials: J
authors.lastname: Wang
authors.forename: Osamu
authors.initials: O
authors.lastname: Sakai
mesh_terms: D000368:Aged; D001810:Blood Volume / Q000502:physiology / Q000528:radiation effects; D059248:Chemoradiotherapy; D003680:Deglutition Disorders / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D015999:Multivariate Analysis; D010609:Pharyngeal Muscles / Q000098:blood supply / Q000000981:diagnostic imaging / Q000528:radiation effects*; D011446:Prospective Studies; D050397:Radiotherapy, Intensity-Modulated; D012039:Regional Blood Flow / Q000502:physiology / Q000528:radiation effects; D012907:Smoking; D013997:Time Factors; D047368:Tumor Burden