title: Relationship between the phase angle and volume of tumours in patients with lung cancer.
abstract: OBJECTIVE
  The phase angle (PA) obtained by bioelectrical impedance has been used as a predictor of nutritional status in cancer. This study aimed to verify the association between the PA and tumour volume in non-small cell lung cancer (NSCLC) patients.
  
  
  METHODS
  Volumetric determination of the tumour mass was performed using a computerised image analysis system incorporated in helical tomography. Lesion segmentation was performed by a semi-automatic process using a region growth algorithm with voxel aggregation. The PA was measured by bioelectrical impedance.
  
  
  RESULTS
  A total of 30 male patients with a mean age of 65.6 years were evaluated. The mean values observed for body mass index, PA and tumour volume were 22.5 ± 4.19, 5.66 ± 0.9° and 163.2 ± 207.5 ml, respectively. The tumour volumes were negatively correlated with the PA (r = -0.55; p < 0.001) and positively correlated with the ratio between the extracellular mass and the body cell mass (ECM/BCM) (r = 0.59; p < 0.001). In multivariate analysis, independent predictors for both PA and ECM/BCM were tumour volume and Karnofsky performance status score.
  
  
  CONCLUSIONS
  In NSCLC, the PA is closely associated with tumour volume, which may be important in early nutritional intervention.
authors.affiliation: University Centre for Cancer Control, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Ivany Alves
authors.initials: IA
authors.lastname: Castanho
authors.forename: Agnaldo José
authors.initials: AJ
authors.lastname: Lopes
authors.forename: Josely Correa
authors.initials: JC
authors.lastname: Koury
authors.forename: Bernardo
authors.initials: B
authors.lastname: Tessarollo
authors.forename: Aristófanes Corrêa
authors.initials: AC
authors.lastname: Silva
authors.forename: Rodolfo Acatauassú
authors.initials: RA
authors.lastname: Nunes
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001823:Body Composition; D015992:Body Mass Index; D002289:Carcinoma, Non-Small-Cell Lung / Q000150:complications / Q000473:pathology*; D003430:Cross-Sectional Studies; D017097:Electric Impedance; D006801:Humans; D008297:Male; D044342:Malnutrition / Q000150:complications / Q000503:physiopathology; D008875:Middle Aged; D015999:Multivariate Analysis; D009752:Nutritional Status; D047368:Tumor Burden