Basic Original ReportStereotactic Body Radiation Therapy for Nonspine Bone Metastases: International Practice Patterns to Guide Treatment Planning
Introduction
Accumulating evidence favors stereotactic body radiation therapy (SBRT) over conventional palliative radiation therapy (cRT) for bone metastases, particularly in the oligometastatic setting.1, 2., 3 Currently, nonspine bone metastases (NSBM) reports in the literature are limited, with a recent systematic review of bone SBRT revealing only 8 of the 57 analyzed studies included NSBM and merely 2 studied an NSBM population exclusively.4 A recent phase II trial showed improved pain response rates with single-fraction SBRT compared with cRT.1 However, the method of target delineation was not clear and the SBRT doses selected were based on an institutional protocol alone. Herein, we surveyed international radiation oncologists with expertise in NSBM-SBRT to better understand worldwide practice patterns to inform clinical management and future research.
Section snippets
Methods and Materials
Nine radiation oncologists representing Canada, the United States, Australia, Switzerland, the Netherlands, and Korea were invited to participate based on expertise in delivering NSBM-SBRT demonstrated through publications or clinical experience. Experts were sent the treatment planning computed tomography (CT) and magnetic resonance images (MRIs) for each of the 11 NSBM cases with the gross tumor volume (GTV) contoured. Cases were purposefully selected to represent a range of bony sites,
Results
All experts agreed to participate and the survey completion rate was 100%.
Discussion
We demonstrate significant heterogeneity worldwide in the delivery of NSBM-SBRT, particularly with respect to treatment technique and dose. Although this highlights the need for guidelines to inform clinical practice and trial design, there were areas of agreement that can guide treating radiation oncologists in the meantime. All experts prescribed a BED of ≤100 Gy10, and >50% of selected dose fractionations had a BED of 60 Gy10. Other practice similarities shared by a majority of surveyed
Conclusions
Significant heterogeneity exists in international radiation techniques and dose-fractionations for NSBM-SBRT, which supports the need for clinical trials and consensus guidelines. Nonetheless, these data demonstrate expert agreement on selecting dose schedules with a BED ≤ 100 Gy10, reasons for dose de-escalation, and in determining acceptable dose schedules based on bony site.
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Practice and principles of stereotactic body radiation therapy for spine and non-spine bone metastases
2024, Clinical and Translational Radiation OncologyEvaluation of the clinical feasibility of cone-beam computed tomography guided online adaption for simulation-free palliative radiotherapy
2023, Physics and Imaging in Radiation OncologyStereotactic Body Radiation Therapy for Metastases in Long Bones
2022, International Journal of Radiation Oncology Biology PhysicsCitation Excerpt :We observed local failure in 9 of the 110 metastases (8.2%), and the median time to local failure after SBRT was long, 28 months (range, 4-48 months). Cumulative incidence of local failure of 13.5% at 3 years is comparable with local failure rates after SBRT for metastases in other nonspine bones,12,13 which is expected considering the use of sufficiently high radiation doses in our study.14 Increased post-SBRT bone remodeling, recalcification, and reossification reported previously15,16 might also contribute to the low incidence of pathologic fracture.
Data sharing: Research data are stored in an institutional repository and will be shared upon request to the corresponding author.
Sources of support: No funding was obtained for this study.
Disclosures: Dr Eppinga reports personal fees from Elekta, outside the submitted work. Dr Lo reports grants from Elekta AB, outside the submitted work, and he was a part of the Gamma Knife ICON expert group. Dr Redmond reports grants and personal fees from Accuray, grants and personal fees from Elekta, personal fees from BioMimetix, and personal fees from Brainlab outside the submitted work. Dr Arjun Sahgal has been an advisor/consultant with Abbvie, Merck, Roche, Varian (Medical Advisory Group), and Elekta (Gamma Knife Icon); is an ex officio board member on the board of the International Stereotactic Radiosurgery Society (ISRS); received honorarium for past educational seminars with Elekta AB, Accuray Inc, Varian (CNS Teaching Faculty), BrainLAB, and Medtronic Kyphon; received a research grant from Elekta AB; and had travel accommodations/expenses paid by Elekta, Varian, and BrainLAB. Dr Sahgal also belongs to the Elekta MR Linac Research Consortium, Elekta Spine, and Oligometastases and Linac Based SRS Consortia. Dr Siva reports grants from Varian Industries; grants from Merck-Sharp-Dohme; grants, personal fees, and other from Astra Zeneca; personal fees from Bristol Meyer Squibb; personal fees from Astellas; personal fees from Janssen; and personal fees from Roche outside the submitted work. Dr Dagan reports personal fees from Elekta and personal fees from UptoDate outside the submitted work. Dr. Tseng reports travel accommodations/expenses and honoraria for past educational seminars by Elekta, belongs to the Elekta MR Linac Research Consortium, and has been an advisor/consultant for Sanofi.