Stereotactic radiotherapy for spinal and non-spinal bone metastases: a patterns-of-care analysis in German-speaking countries as part of a project of the interdisciplinary Radiosurgery and Stereotactic Radiotherapy Working Group of the DEGRO/DGMP.

Background And Purpose: Bone metastases constitute a common indication for both conventional radiotherapy (RT) and stereotactic body radiotherapy (SBRT). Although in recent years guidelines have been proposed for SBRT of spinal and non-spinal metastases, little is known about the use of bone SBRT and the actual patterns of care in German-speaking countries.

Material And Methods: We performed an online survey among radiation oncologists (ROs) registered with the interdisciplinary Radiosurgery and Stereotactic Radiotherapy Working Group of the German Society of Radiation Oncology (DEGRO) and the German Society for Medical Physics (DGMP) to collect valuable and robust cross-sectional data on patterns of care for bone SBRT in German-speaking countries.

Results: Of the registered ROs, 35.5% (75/211) completed the online survey. ROs working in high-volume centers irradiating more than 100 patients with bone metastases annually represented the largest group, with 58.7%. Ablative SBRT was mostly performed for bone oligometastases (78.7%). For symptom-directed palliative radiotherapy, the majority of responding physicians (84.3%) still mostly recommend moderately hypofractionated treatment. Nevertheless, 60.9% of participating ROs stated using bone SBRT at least occasionally, also for palliative purposes such as pain control. Our survey also revealed a certain reluctance for the concomitant use of systemic therapies with bone SBRT and heterogeneity regarding target volume definition and dosing for bone SBRT.

Conclusion: Our survey demonstrates that bone SBRT for spinal and non-spinal metastases for oligometastatic disease (OMD) is broadly available in clinical routine care in German-speaking countries. A large heterogeneity regarding indications, dose, and fractionation concepts remains, requiring further efforts for standardization of bone SBRT.