RESUMO
Three-dimensional (3D) camera systems are increasingly used for computerized volume calculations. In this study we investigate whether the Vectra XT 3D imaging system is a reliable tool for determination of breast volume in clinical practice. It is compared with the current gold standard in literature, magnetic resonance imaging (MRI), and current clinical practice (plastic surgeon's clinical estimation). METHODS: Breast volumes of 29 patients (53 breasts) were evaluated. 3D images were acquired by Vectra XT 3D imaging system. Pre-existing breast MRI images were collected. Both imaging techniques were used for volume analyses, calculated by two independent investigators. Breast volume estimations were done by plastic surgeons during outpatient consultations. All volume measurements were compared using paired samples t-test, intra-class correlation coefficient, Pearson's correlation, and Bland-Altman analysis. RESULTS: Two 3D breast volume measurements showed an excellent reliability (intra-class correlation coefficient: 0.991), which was comparable to the reliability of MRI measurements (intra-class correlation coefficient: 0.990). Mean (SD) breast volume measured with 3D breast volume was 454 cm3 (157) and with MRI was 687 cm3 (312). These volumes were significantly different, but a linear association could be found: y(MRI) = 1.58 × (3D) - 40. Three-dimensional breast volume was not significantly different from volume estimation made by plastic surgeons (472 cm3 (69), P = 0.323). CONCLUSIONS: The 3D imaging system measures lower volumes for breasts than MRI. However, 3D measurements show a linear association with MRI and have excellent reliability, making them an objective and reproducible measuring method suitable for clinical practice.
RESUMO
Background: In the past, measurement of upper limb lymphedema was done by water displacement (WD), which is frequently cited as the gold standard. For various reasons, however, the use of WD is restricted in clinical settings. A more precise and easy-to-use method would be favorable. The high precision of three-dimensional (3D) imaging in comparison to WD has already been reported for healthy subjects. The aim of this study is to determine the validity and reliability of 3D imaging by comparing it to the WD method in women with unilateral upper limb lymphedema. Methods and Results: Thirty-nine women with unilateral breast cancer-related lymphedema (BCRL) were included, of which 37 completed two volume measurement techniques (3D and WD) on the BCRL and contralateral healthy arm. Slightly larger volumes were measured by the WD method in healthy arms (+9.8 mL; p = 0.058) and also in BCRL arms (+18.5 mL; p < 0.001). All measurements were performed twice by the same researcher to evaluate reliability. There was no significant difference between the two measurements for healthy arms (p = 0.323) or BCRL arms (p = 0.807) in 3D imaging. Bland-Altman plots showed a high limit of agreement between the single measurements. 3D imaging had a high intrarater reliability (Intraclass Correlation Coefficient = 0.999). Conclusion: Results show that 3D imaging is an innovative method for measuring upper limb volume in BCRL patients. Even though image processing is time consuming, 3D imaging combines high reproducibility with high precision. By software automation, this technique could easily be integrated into clinical routine. It is for this reason that we would recommend implementing the Vectra 3D imaging technique for measurement of BCRL.