title: Prediction of locoregional control in head and neck squamous cell carcinoma with serial CT perfusion during radiotherapy.
abstract: OBJECTIVE
  Tumor hypoxia is a known factor of radioresistance in HNSCC. CTP is a noninvasive method of measuring tumor perfusion in vivo. The purpose of our study was to determine serial changes in tumor perfusion in HNSCC during a course of RT by using CTP and to correlate tumor perfusion measurements to LRC.
  
  
  METHODS
  A prospective study was performed in 15 patients with HNSCC receiving definitive RT who underwent serial CTP before RT; at weeks 2, 4, and 6 of RT; and 6 weeks after RT. The median follow-up was 28 months (range, 6-44 months). Thirteen patients achieved LRC, and 2 patients had LRF. Tumor perfusion parameters, including BF, BV, MTT, and CP, were obtained by using a deconvolution-based analysis.
  
  
  RESULTS
  Pretreatment tumor BF was significantly higher in patients who achieved LRC, 118.0 mL/100 g/min, compared with those with LRF, 53.4 mL/100 g/min (P = .004). Similarly, pretreatment CP was higher in patients with LRC, 16.6 mL/100 g/min, compared with those with LRF, 7.7 mL/100 g/min (P = .02). At week 2 of RT, tumor BF parameters showed a 27.5% increase versus an 18.1% decrease from pretreatment BF values (P = .046) in patients with LRC and LRF, respectively. A decrease in BF and BV was observed in both groups 6 weeks after RT compared with these values at baseline scanning.
  
  
  CONCLUSIONS
  An increase in tumor BF and CP by using CTP early during a course of RT predicts LRC in patients with HNSCC treated with RT.
authors.affiliation: Departments of Radiology, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts, USA. mitruong@bu.edu
authors.forename: M T
authors.initials: MT
authors.lastname: Truong
authors.forename: N
authors.initials: N
authors.lastname: Saito
authors.forename: A
authors.initials: A
authors.lastname: Ozonoff
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.forename: R
authors.initials: R
authors.lastname: Lee
authors.forename: M M
authors.initials: MM
authors.lastname: Qureshi
authors.forename: S
authors.initials: S
authors.lastname: Jalisi
authors.forename: O
authors.initials: O
authors.lastname: Sakai
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011878:Radiotherapy / Q000379:methods; D015996:Survival Rate; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome