Cross-calibration, Least Significant Change and Quality Assurance in Multiple Dual-Energy X-ray Absorptiometry Scanner Environments: 2019 ISCD Official Position.

In preparation for the International Society for Clinical Densitometry Position Development Conference (PDC) 2019 in Kuala Lumpur, Malaysia, a cross-calibration and precision task force was assembled and tasked to review the literature, summarize the findings, and generate positions to answer 4 related questions provided by the PDC Steering Committee, which expand upon the current ISCD official positions on these subjects. (1) How should a provider with multiple dual-energy X-ray absorptiometry (DXA) scanners of the same make and model calculate least significant change (LSC)? (2) How should a provider with multiple DXA systems with the same manufacturer but different models calculate LSC? (3) How should a provider with multiple DXA systems from different manufacturers and models calculate LSC? (4) Are there specific phantom procedures that one can use to provide trustworthy in vitro cross calibration for same models, different models, and different makes? Based on task force deliberations and the resulting systematic literature reviews, 3 new positions were developed to address these more complex scenarios not addressed by current official positions on single scanner cross calibration and LSC. These new positions provide appropriate guidance to large multiple DXA scanner providers wishing to offer patients flexibility and convenience, and clearly define good clinical practice requirements to that end.

Executive Summary of the 2019 ISCD Position Development Conference on Monitoring Treatment, DXA Cross-calibration and Least Significant Change, Spinal Cord Injury, Peri-prosthetic and Orthopedic Bone Health, Transgender Medicine, and Pediatrics.

To answer important questions in the fields of monitoring with densitometry, dual-energy X-ray absorptiometry machine cross-calibration, monitoring, spinal cord injury, periprosthetic and orthopedic bone health, transgender medicine, and pediatric bone health, the International Society for Clinical Densitometry (ISCD) held a Position Development Conference from March 20 to 23, 2019. Potential topics requiring guidance were solicited from ISCD members in 2017. Following that, a steering committee selected, prioritized, and grouped topics into Task Forces. Chairs for each Task Force were appointed and the members were co-opted from suggestions by the Steering Committee and Task Force Chairs. The Task Forces developed key questions, performed literature searches, and came up with proposed initial positions with substantiating draft publications, with support from the Steering Committee. An invited Panel of Experts first performed a review of draft positions using a modified RAND Appropriateness Method with voting for appropriateness. Draft positions deemed appropriate were further edited and presented at the Position Development Conference meeting in an open forum. A second round of voting occurred after discussions to approve or reject the positions. Finally, a face-to-face closed session with experts and Task Force Chairs, and subsequent electronic follow-up resulted in 34 Official Positions of the ISCD approved by the ISCD Board on May 28, 2019. The Official Positions and the supporting evidence were submitted for publication on July 1, 2019. This paper provides a summary of the all the ISCD Adult and Pediatric Official Positions, with the new 2019 positions highlighted in bold.

Best Practices for Dual-Energy X-ray Absorptiometry Measurement and Reporting: International Society for Clinical Densitometry Guidance.

Dual-energy X-ray absorptiometry (DXA) is a technology that is widely used to diagnose osteoporosis, assess fracture risk, and monitor changes in bone mineral density (BMD). The clinical utility of DXA is highly dependent on the quality of the scan acquisition, analysis, and interpretation. Clinicians are best equipped to manage patients when BMD measurements are correct and interpretation follows well-established standards. Poor-quality acquisition, analysis, or interpretation of DXA data may mislead referring clinicians, resulting in unnecessary diagnostic evaluations, failure to evaluate when needed, inappropriate treatment, or failure to provide medical treatment, with potentially ineffective, harmful, or costly consequences. Misallocation of limited healthcare resources and poor treatment decisions can be minimized, and patient care optimized, through meticulous attention to DXA instrument calibration, data acquisition and analysis, interpretation, and reporting. This document from the International Society for Clinical Densitometry describes quality standards for BMD testing at DXA facilities worldwide to provide guidance for DXA supervisors, technologists, interpreters, and clinicians. High-quality DXA testing is necessary for correct diagnostic classification and optimal fracture risk assessment, and is essential for BMD monitoring.

The effect of extending femur scan length on BMD results on the Hologic Discovery-W scanner.

A longer dual-energy X-ray absorptiometry scan field of the hip may be useful for the detection of atypical subtrochanteric femur fractures. It has been demonstrated in a Prodigy GE/Lunar scanner that extending the scan length does not affect bone mineral density (BMD) results at the total hip or femoral neck. We hypothesized that extending the scan field on a Hologic Discovery scanner would also have no effect on BMD results at the hip. Thirty subjects who presented for standard of care dual-energy X-ray absorptiometry scans underwent paired default (15.2 cm) and extended (24.1 cm) length hip scans. There was no significant difference in the total hip or any of the component subregions of femoral neck, greater trochanter, or intertrochanteric (shaft) BMD between the default and extended length scans.

Proceedings of the 2011 Santa Fe Bone symposium.

The 11th Santa Fe Bone Symposium was held in Santa Fe, NM, USA, on August 6-7, 2010. This annual event addresses the clinical relevance of recent scientific advances in the fields of osteoporosis and metabolic bone disease. The symposium format included plenary presentations, oral abstracts, and interactive panel discussions, with participation of clinicians, researchers, and bone densitometry technologists. Among the many topics included in the symposium were new developments in nutritional therapy for osteoporosis, parathyroid hormone for the assessment and treatment of skeletal disease, osteoporosis in men, new and emerging concepts in osteoporosis therapy, report on the 2010 International Society for Clinical Densitometry (ISCD)-International Osteoporosis Foundation FRAX Initiative and the ISCD Position Development Conference, balancing benefits and risks of bisphosphonate therapy, and an advanced bone densitometry workshop for clinicians and technologists.

Skeletal sites for osteoporosis diagnosis: the 2005 ISCD Official Positions.

The International Society for Clinical Densitometry (ISCD) has developed Official Positions to assist healthcare providers in addressing some of the issues inherent with the use of bone mineral density (BMD) assessed by dual-energy X-ray absorptiometry (DXA) to diagnose osteoporosis, apply World Health Organization (WHO) T-score classifications, and monitor BMD changes over time. Differences exist, however, between the ISCD Official Position statement and that of the International Osteoporosis Foundation with respect to WHO criteria for skeletal sites. Consequently, a subcommittee of the ISCD was directed to address the application of the WHO classifications to specific skeletal sites and regions of interest. In 2005, the ISCD Position Development Conference reviewed the findings and prepared Official Positions, which address whether or not: (1) the lowest T-score of the total proximal femur, femoral neck, trochanter, and spine should continue to be used for diagnosis; (2) the WHO classification may be applied to a single vertebral body T-score; and (3) the ISCD should endorse the use of the National Health and Nutrition Examination Survey database for proximal femur T-score derivation. The resulting ISCD Official Positions, with their corresponding rationales and evidence are provided here, as well as questions that will need to be addressed in the future.