Radiofrequency echographic multi-spectrometry for diagnosing osteoporosis

A European multicenter clinical study that evaluated the diagnostic accuracy of radiofrequency echographic multi-spectrometry (REMS) for osteoporosis has concluded that both REMS sensitivity and specificity are over 90%, when using the current clinical reference technology of dual-energy x-ray absorptiometry (DXA).

The study in the journal Bone found that the Pearson correlation between DXA and REMS-measured bone mineral density (BMD) was over 0.93 for two sites radiofrequency echographic multi-spectrometry

In addition, age-subgroup analysis (spanning from younger and premenopausal to elderly women as old as 90) revealed diagnostic concordance up to 92% and that T-score values discriminated significantly between fractured and non-fractured patients.

REMS is a non-ionizing technology for the densitometric assessment of osteoporosis and has already been validated in Italian women, according to the authors. The current study assessed the accuracy of REMS in a wider European population.

A total of 4,307 female Caucasian patients, aged 30 to 90, were enrolled in the study, from the Hospital del Mar in Barcelona, Spain; the University Hospital of Florence in Italy; the Centre Hospitalier Universitaire (CHU) in Liège, Belgium; the Southampton General Hospital in Southampton, United Kingdom; and the Vito Fazzi Hospital in Lecce, Italy.

The cohorts of patients from each institution were well-balanced for age, height and weight, with no significant differences among groups.

All patients underwent DXA and REMS scans at femoral neck and/or lumbar spine, depending on their medical prescription. A total of 4,245 lumbar spine scans and 4,271 femoral neck scans were performed.

Overall, 8.3% of patients in the femoral neck dataset and 8.2% in the lumbar spine dataset reported a previous fragility fracture.

The ability to discriminate patients with and without osteoporosis by femoral neck investigation resulted in sensitivity and specificity of 90.4% and 95.5%, respectively.

For lumbar spine scans, a sensitivity of 90.9% and a specificity of 95.1% were obtained.

Regarding T-score based comparison, the sensitivity and specificity obtained by REMS in the classification of patients with and without osteoporosis were 85.5% and 94.5%, respectively, for femoral neck cases, and 89.0% and 94.3%, respectively, for lumbar spine cases.

For a 0.3 T-score tolerance, the sensitivity and specificity were 91.1% and 98.0%, respectively, for femoral neck, and 95.4% and 97.1%, respectively, for lumbar spine.

The areas under the curve (AUCs) of the receiver operating characteristic (ROC) curve evaluated the ability to discriminate groups of patients with previous osteoporotic fracture using DXA and REMS. T-score values were 0.631 and 0.683 (P < 0.0001), respectively, for femoral neck scans, and 0.603 and 0.640 (P = 0.0002), respectively, for lumbar spine scans.

“The obtained results showed that REMS had a high accuracy in the identification of patients with osteoporosis, with sensitivity and specificity over 90% and diagnostic concordance of about 86% for both the reference anatomical sites,’ wrote the authors.

The study also confirms the high impact of the borderline cases, meaning cases with DXA and REMS T-score values roughly the same as the transition thresholds between diagnostic classes (for example, a ±0.3 T-score range around the -2.5 and -1 thresholds) and that were reconsidered and accepted as matching classifications, achieved sensitivity and specificity up to the 95% to 99% range for both anatomical sites.

The corresponding diagnostic concordance in three classes also resulted in values over 94% for both anatomical sites.

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Reference

  1. Cortet B, Dennison E, Diez-Perez A, et al. Radiofrequency echographic multi spectrometry (REMS) for the diagnosis of osteoporosis in a European multicenter clinical context. Bone. Published online December 2, 2020. doi:10.1016/j.bone.2020.115786