Does CT-based Rigidity Analysis Influence Clinical Decision-making in Simulations of Metastatic Bone Disease?

Abstract

Background There is a need to improve the prediction of fracture risk for patients with metastatic bone disease. CTbased rigidity analysis (CTRA) is a sensitive and specific method, yet its influence on clinical decision-making has never been quantified. Questions/purposes What is the influence of CTRA on providers' perceived risk of fracture? (2) What is the influence of CTRA on providers' treatment recommendations in simulated clinical scenarios of metastatic bone disease of the femur? (3) Does CTRA improve interobserver agreement regarding treatment recommendations? Methods We conducted a survey among 80 academic physicians (orthopaedic oncologists, musculoskeletal radiologists, and radiation oncologists) using simulated vignettes of femoral lesions presented as three separate scenarios: (1) no CTRA input (baseline); (2) CTRA input suggesting increased risk of fracture (CTRA+); and (3) CTRA input suggesting decreased risk of fracture (CTRAÀ). Participants were asked to rate the patient's risk of fracture on a scale of 0% to 100% and to provide a treatment recommendation. Overall response rate was 62.5% (50 of 80). Results When CTRA suggested an increased risk of fracture, physicians perceived the fracture risk to be slightly greater (37% ± 3% versus 42% ± 3%, p \ 0.001; mean difference [95% confidence interval {CI}] = 5% [4.7%-5.2%]) and were more prone to recommend surgical stabilization (46% ± 9% versus 54% ± 9%, p \ 0. suggested a decreased risk of fracture, physicians perceived the risk to be slightly decreased (37% ± 25% versus 35% ± 25%, p = 0.04; mean difference [95% CI] = 2% [2.74%-2.26%]) and were less prone to recommend surgical stabilization (46% ± 9% versus 42% ± 9%, p \ 0.03; mean difference [95% CI] = 4% [3.9-5.1]). The effect size of the influence of CTRA on physicians' perception of fracture risk and treatment planning varied with lesion severity and specialty of the responders. CTRA did not increase interobserver agreement regarding treatment recommendations when compared with the baseline scenario (j = 0.41 versus j = 0.43, respectively). Conclusions Based on this survey study, CTRA had a small influence on perceived fracture risk and treatment recommendations and did not increase interobserver agreement. Further work is required to properly introduce this technique to physicians involved in the care of patients with metastatic lesions. Given the number of preclinical and clinical studies outlining the efficacy of this technique, better education through presentations at seminars/webinars and symposia will be the first step. This should be followed by clinical trials to establish CTRA-based clinical guidelines based on evidence-based medicine. Increased exposure of clinicians to CTRA, including its underlying methodology to study bone structural characteristics, may establish CTRA as a uniform guideline to assess fracture risk. Level of Evidence Level III, economic and decision analyses.

Finite element analysis potentially identifies nonessential prophylactic stabilization in femurs with metastatic disease

“…A true assessment of model-predicted fracture probability in a prospective study would be challenging given the ethical dilemma of withholding surgical treatment in a patient considered to be at high risk of fracture. Given only the moderate agreement amongst surgeons regarding treatment recommendation 19 and hesitancy in clinical implementation, the most appropriate next step would be to utilize the model in a prospective, multi-institutional setting specifically to identify patients at the lowest computed mechanical risk of fracture (e.g. LSR < 0.4), which, considering the zero incidence of fracture in this group, may justify non-operative management and close observation.…”

ESTRO ACROP guidelines for external beam radiotherapy of patients with complicated bone metastases

“…On CT the risk of fracture can be determined by the structural rigidity analysis (CTRA), using tissue mineral density and crosssectional geometry to determine changes to structural competency of the bone induced by lytic lesions [73,78,79].…”

Management of Pathologic Fractures around the Knee: Part 1—Distal Femur

“…Recent literature has found CTRA to be a better predictor of impending femoral pathologic fractures than Mirels' criteria. 78 79 The CT-based finite element analysis (CTFEA) is another engineering method that has been shown to potentially provide risk assessment for impending fracture with a reported specificity of 63%. 80 Despite encouraging results of these CT imaging modalities, further research is required before they should surpass Mirels' criteria as the gold standard for evaluation of patients with impending pathologic fractures.…”