Efficacy of Radiation Therapy
Clinicians should consider the use of radiation therapy to decrease the rate of femur fractures in patients with metastatic carcinoma or multiple myeloma lesions who are deemed at increased risk based on the combination of imaging findings and lesion-related pain.

Rationale

One observational study of moderate quality (Oh E. et al. 2017) among patients with metastatic lung cancer indicates a higher risk of fracture among patients with femoral metastases not treated with radiation therapy, as compared to those treated with radiation therapy.  Other risk factors included lytic femur metastasis morphology and female gender. Though these data are limited to femur metastases from lung cancer and there is no randomized evidence to guide practice, the evidence and related recommendation was considered moderate strength given the high morbidity of femur fractures and the low morbidity of radiation therapy to the femur.

This recommendation addresses the question of whether radiation by itself can reduce the risk of fracture. It is not intended to alter current clinical practice wherein patients who are felt to be at high risk of pathologic fracture first undergo prophylactic stabilization.

Future Research

Future research should address which femur metastases are most at risk for fracture, and hence further define when radiation therapy is required. Patients who suffer local recurrence of tumor within the femur after radiation therapy appear to have an increased risk of lesion-related pain, fracture, and need for surgical intervention. Further research is needed to accurately identify specific populations of patients who are at increased risk of tumor recurrence within the femur after radiation therapy, and to determine the risks and benefits associated with any interventions that are intended to reduce these risks.