title: Contrast-enhanced color duplex sonography (CDS): an alternative for the evaluation of therapy-relevant tumor oxygenation?
abstract: OBJECTIVE
  To evaluate the predictive value of radiotherapeutically relevant tumor hypoxia by contrast-enhanced color duplex sonography (CDS). The objectification was based on pO(2) histography.
  
  
  METHODS
  25 patients with metastatic neck lymph node from a primary squamous carcinoma of the head and neck were examined. To visualize as many vessels as possible, a contrast enhancer (Levovist), Schering Corp., Germany) was administered. Horizontal and longitudinal sonographic scans with a thickness of 5 mm were performed on the metastatic neck lymph node. Color pixel density (CPD) was defined as the ratio of colored to gray pixels in a region of interest. It represents the extent of vascularization in the investigated slice. To assess the biological and clinical relevance of oxygenation measurement, the relative frequency of pO(2) readings < or = 2.5, 5.0, and 10.0 mmHg, as well as mean and median pO(2), were documented.
  
  
  RESULTS
  In order to investigate the degree of linear association, the Pearson correlation coefficient was calculated. Moderate (/r/ > 0.5) to high (/r/ > 0.7) correlation was found between the CPD and the parameters of hypoxic fraction (pO(2) readings with values < or = 5.0 and 10.0 mmHg, as well as mean and median). There was only a slight correlation between CPD and the fraction of pO(2) values < or = 2.5 mmHg (r = -0.479).
  
  
  CONCLUSIONS
  CPD represents the mean degree of vascularization. As a noninvasive measurement, this method seems feasible for evaluating the state of global oxygenation in superficial tumors. Nevertheless, this method is limited through its deficiency in describing the vascular heterogeneity of tumors.
authors.affiliation: Department of Radiotherapy, University of Aachen, Aachen, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Gagel
authors.forename: Ercole
authors.initials: E
authors.lastname: DiMartino
authors.forename: Oliver
authors.initials: O
authors.lastname: Schramm
authors.forename: Michael
authors.initials: M
authors.lastname: Pinkawa
authors.forename: Marc
authors.initials: M
authors.lastname: Piroth
authors.forename: Cengiz
authors.initials: C
authors.lastname: Demirel
authors.forename: Payam
authors.initials: P
authors.lastname: Maneschi
authors.forename: Sven
authors.initials: S
authors.lastname: Stanzel
authors.forename: Branka
authors.initials: B
authors.lastname: Asadpour
authors.forename: Martin
authors.initials: M
authors.lastname: Westhofen
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Eble
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000556:secondary*; D003287:Contrast Media; D018618:Echocardiography, Doppler, Color / Q000379:methods*; D005260:Female; D006258:Head and Neck Neoplasms / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000378:metabolism; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging* / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D010100:Oxygen