title: Assessment of volume measurement of breast cancer-related lymphedema by three methods: circumference measurement, water displacement, and dual energy X-ray absorptiometry.
abstract: BACKGROUND
  Following treatment for breast cancer 12%-60% develop breast cancer-related lymphedema (BCRL). There are several ways of assessing BCRL. Circumference measurement (CM) and water displacement (WD) for volume measurements (VM) are frequently used methods in practice and research, respectively. The aim of this study was to evaluate CM and WD for VM of the BCRL arm and the contralateral arm, comparing the results with regional dual energy X-ray absorptiometry (DXA).
  
  
  RESULTS
  Twenty-four women with unilateral BCRL were included in the study. Blinded duplicate VM were obtained from both arms using the three methods mentioned above. CM and DXA were performed by two observers. WD was performed by a group of observers. Mean differences (d) in duplicated volumes, limits of agreement (LOA), and 95% confidence intervals (CI) were calculated for each method. The repeatability expressed as d (95% CI) between the duplicated VM of the BCRL arm and the contralateral arm was for DXA 3 ml (-6-11) and 3 ml (1-7), respectively. For CM and WD, the d (95% CI) of the BCRL arm were 107 ml (86-127) and 26 ml (-26-79), respectively and in the contralateral arm 100 ml (78-122) and -6 ml (-29-17), respectively.
  
  
  CONCLUSIONS
  DXA is superior in repeatability when compared to CM and WD for VM, especially for the BCRL arm but also the contralateral arm.
authors.affiliation: Department of Clinical Physiology and Nuclear Medicine, Herlev University Hospital, Herlev, Denmark. caroline@gjorup.com
authors.forename: Caroline
authors.initials: C
authors.lastname: Gjorup
authors.forename: Bo
authors.initials: B
authors.lastname: Zerahn
authors.forename: Helle W
authors.initials: HW
authors.lastname: Hendel
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D001132:Arm / Q000473:pathology; D001834:Body Water / Q000378:metabolism; D001943:Breast Neoplasms / Q000150:complications*; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D008209:Lymphedema / Q000175:diagnosis* / Q000209:etiology; D008875:Middle Aged; D015203:Reproducibility of Results