Objectives Sarcopenia is the quantitative and qualitative loss of skeletal muscle, which may be associated with acute surgical menopause after risk-reducing salpingo-oophorectomy (RRSO) in BRCA1/2 PV carriers. Magnetic Resonance Imaging (MRI) and Computed-Tomography (CT) are currently the golden standard to measure muscle mass. Dual Energy X-ray Absorptiometry (DEXA) is less costly with less radiation exposure. As there are no data on its intra- and inter-observer variability, the aim of this study was to establish if the DEXA scan could be a reliable alternative to CT or MRI in the analysis of muscle mass.

Methods To assess inter- and intra-observer variability, DEXA scans of the lower extremities of women 10 or more years after RRSO were analyzed by two observers, who independently analyzed each scan twice. Information about costs and radiation dose from the DEXA, CT and MRI were collected from literature.

Results DEXA scans of 34 women with a median age of 58.0 years (range 45.0–73.0) and a median BMI of 24.6 (range 18.0–47.2) were analysed. Inter-observer variability had an Interclass correlation coefficient (ICC) of 0.997 and acceptable limits of agreement. Intra-observer variability was also low: ICC_observer1:0.998 and ICC_observer2:0.997. Observer 1 had lower limits of agreement. Costs and radiation exposure were lower for DEXA than CT and MRI.

Conclusions The assessment of muscle mass of the lower extremities with DEXA scan has a high reliability, is less costly and has a lower radiation dose than CT and MRI. DEXA scan may be a good alternative for measuring muscle mass to diagnose sarcopenia.