BACKGROUND AND PURPOSE Patients with advanced cancer may develop painful bone metastases, potentially resulting in pathological fractures. Adequate fracture risk assessment is of key importance to prevent fracturing and maintain mobility. This study aims to validate the clinical reliability of axial cortical involvement with a 30 mm threshold on conventional radiographs to assess fracture risk in femoral bone metastases. MATERIALS AND METHODS All patients with bone metastases who received radiotherapy for pain included in two multicentre prospective studies were selected. Conventional radiographs obtained at a maximum of two months prior to radiotherapy were collected. Three experts independently measured lesions and scored radiographic characteristics. Sensitivity, specificity, positive (PPV) and negative predictive value (NPV) were calculated. RESULTS Hundred patients were included with a median follow-up of 23.0 months (95%CI: 10.6-35.5). Two fractures occurred in lesions with axial cortical involvement <30 mm, and 12 in lesions ≥30 mm. Sensitivity, specificity, PPV and NPV of axial cortical involvement for predicting femoral fractures were 86%, 50%, 20% and 96%, respectively. Patients with lesions ≥30 mm had a 5.3 times higher fracture risk than patients with smaller lesions. CONCLUSION Our validation study confirmed the use of 30 mm axial cortical involvement to assess fracture risk in femoral bone metastases. Until a more accurate and practically feasible method has been developed, this clinical parameter remains an easy method to assess femoral fracture risk to aid patients and clinicians to choose the optimal individual treatment modality.

中文翻译：

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转移性病变的轴向皮质受累，以确定即将发生的股骨骨折；临床验证研究

背景和目的晚期癌症患者可能会发生疼痛的骨转移，可能导致病理性骨折。充分的裂缝风险评估对于防止裂缝和保持流动性至关重要。本研究旨在验证在常规 X 光片上以 30 毫米阈值评估股骨骨转移骨折风险的轴向皮质受累的临床可靠性。材料与方法 选择了两项多中心前瞻性研究中所有因疼痛接受放射治疗的骨转移患者。收集最多在放疗前两个月获得的常规射线照片。三位专家独立测量病变并对放射学特征进行评分。计算敏感性、特异性、阳性（PPV）和阴性预测值（NPV）。结果 一百名患者被纳入，中位随访时间为 23.0 个月（95%CI：10.6-35.5）。中轴皮质受累<30 mm 的病变发生2 次骨折，≥30 mm 的病变发生12 次骨折。预测股骨骨折的轴向皮质受累的敏感性、特异性、PPV 和 NPV 分别为 86%、50%、20% 和 96%。病灶≥30 mm 的患者骨折风险比病灶较小的患者高 5.3 倍。结论 我们的验证研究证实了使用 30 mm 轴向皮质受累来评估股骨骨转移的骨折风险。在开发出更准确和实际可行的方法之前，该临床参数仍然是评估股骨骨折风险的简便方法，可帮助患者和临床医生选择最佳的个体化治疗方式。