Precision of Lunar Dual-energy X-ray Absorptiometry (iDXA) in measuring body composition among colorectal cancer patients and healthy subjects

Abstract

Background & aims: High quality and precise methods are needed when monitoring changes in body composition among colorectal cancer (CRC) patients and healthy subjects. The aim of this study was to estimate precision of the Dual-energy X-ray absorptiometry (Lunar iDXA, GE Healthcare software enCORE version 16) in measuring body composition in CRC patients and healthy subjects. Methods: Precision error of iDXA in measuring body composition was investigated in the current study. Thirty CRC patients and 30 healthy subjects, including both men and women underwent two consecutive whole-body DXA scan with repositioning. Precision estimates of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) in the abdominal region, and total fat mass (FM), fat-free mass (FFM), lean mass (LM), bone mineral density (BMD) and bone mineral content (BMC) were calculated. Results: Precision error expressed as coefficient of variation (% CV) of VAT and SAT were estimated to be 3.56% and 3.28% among CRC patients, and 5.30% and 3.46% among healthy subjects. Estimated precision errors for body masses in the total region ranged between 0.49-1.01% and 0.40e0.88% in CRC patients and healthy subjects, respectively. Least significant change (LSC) in VAT mass, SAT mass, FM and LM were 140.9 g, 121.4 g, 637.0 g and 701.0 g, respectively, among CRC patients. Among healthy subjects the LSC in VAT, SAT, FM and LM were 80.93 g, 98.90 g, 484.0 g and 618.0 g, respectively. Only minor and nonsignificant differences between the two consecutive measurements for each body compartment were observed within both populations, and we found no systematic bias in the distribution of the differences. Conclusion:The Lunar iDXA demonstrated high precision in body composition measurements among both CRC patients and healthy subjects. Hence, iDXA is a useful tool in clinical following-up and interventions targeted towards changes in body composition.

Comparison of the Discovery A and Stratos DR densitometers for assessing whole‐body and regional bone mineral density and body composition

“…In the absence of other works evaluating the precision of the Stratos DR, we could only compare our results to those previously obtained for other manufacturers. Nevertheless, our findings seem to be in accordance with the precision reported for the Lunar iDXA (ranging from 0.4% to 1%) (Henriksen et al, 2021; Hind et al, 2011; Rothney et al, 2012; Watson et al, 2017) and better than that of older generation DXA models such as Prodigy (ranging from 0.8% to 2.5%) (Oldroyd et al, 2003). It has also been suggested that the population studied and, particularly, an increase in body size can alter the precision of the measurement (Barlow et al, 2015; Hind et al, 2011; Knapp et al, 2012).…”

“…The ISCD recommends that the minimum acceptable precision error within a population of interest should not exceed 3% for WB FM and 2% for WB FFST (Shuhart et al, 2019), which was the case in our study (<1.4%). These results indicated the good precision of the Stratos DR. We note than FFST showed a lower precision error compared to FM, which has previously been reported (Barlow et al, 2015; Bazzocchi et al, 2016; Henriksen et al, 2021; Rothney et al, 2012). In the absence of other works evaluating the precision of the Stratos DR, we could only compare our results to those previously obtained for other manufacturers.…”

“…Regional FM and FFST, particularly at the arm, showed higher precision errors than whole body (8.8%−8% vs. 1.4%−1%, respectively), as has also been reported for different manufacturers and in different populations including healthy subjects, patients with obesity or cancer, and athletes (ranging from 2.8% to 11.4%) (Barlow et al, 2015; Henriksen et al, 2021; Knapp et al, 2012; Rothney et al, 2012). These observations appear relevant because one of the criteria to define sarcopenia – the appendicular lean tissue mass index, which is defined as the sum of the FFST of the arms and legs/height² (Cruz‐Jentoft et al, 2019)−needs to be determined with high precision and high reproducibility to monitor the effectiveness of interventions.…”

Piloting a training program in computed tomography skeletal muscle assessment for registered dietitians

“…We additionally report the LSC (2.2%–4.9%) for our cohort, an essential metric for the correct interpretation of change in skeletal muscle over time and response to interventions. In the absence of standardized precision error reporting for L3 CT cross‐sectional skeletal muscle, we note that our values are comparable to the precision error (0.3%–2.0%) and LSC (1.4%–4.5%) reported for assessments of lean mass using DEXA 36,41–44 . Additionally, the cross‐sectional skeletal muscle measurements completed by our cohort of RDs are comparable to those completed by radiologists as reported by Perthen et al 45 In their study, radiologists ( N = 3) performed CT L3 skeletal muscle measurements in duplicate ( N = 29 images) using Hermes software 45 .…”

“…and LSC (1.4%-4.5%) reported for assessments of lean mass using DEXA. 36,[41][42][43][44] Additionally, the cross-sectional skeletal muscle measurements completed by our cohort of RDs are comparable to those completed by radiologists as reported by Perthen et al 45 In their study, radiologists (N = 3) performed CT L3 skeletal muscle measurements in duplicate (N = 29 images) using Hermes software. 45 Although they used different software and did not complete a precision assessment as we did here, radiologists' intraobserver and interobserver variabilities (1.57-2.89 cm…”