NCT07188532

Biologically-Adapted, Dose-Escalated Radiotherapy for the Treatment of Ewing Sarcoma, BEAR Trial

Biologically-Adapted, Dose-Escalated Accelerated Radiotherapy for Ewing Sarcoma (BEAR)

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 141 (estimated)
• Sponsor: Mayo Clinic · Academic / Other
• Sex: All
• Age: 2 Years
• Healthy volunteers: Not accepted

Summary

This clinical trial evaluates the effect of radiotherapy doses based on tumor size and tumor-specific characteristics (biologically-adapted) in treating patients with Ewing sarcoma. Radiotherapy uses high energy x-rays, particles, or radioactive seeds to kill tumor cells and shrink tumors. Conventional radiotherapy uses minimal imaging support to determine the positioning of radiotherapy. Hypofractionated radiotherapy delivers higher doses of radiotherapy over a shorter period of time and may kill more tumor cells and have fewer side effects. Dose-escalated radiotherapy uses doses that are higher than those used in conventional radiotherapy. Larger tumor sizes and other tumor-specific characteristics have been shown to be related to poorer outcomes. In addition, after dose-escalated radiotherapy, patients with larger tumors have demonstrated improved control of the disease at the primary tumor site. Giving biologically-adapted, dose-escalated radiotherapy may reduce the return of the cancer at the primary tumor site in patients with Ewing sarcoma with large tumors and other unfavorable characteristics. This clinical trial also evaluates the role of biomarkers in patients with Ewing sarcoma. Studying samples of blood and tumor tissue from patients with Ewing sarcoma in the laboratory may help doctors learn more about predicting the amount of disease and the likelihood of the cancer coming back.

Conditions

• Ewing Sarcoma
• Round Cell Sarcoma With EWSR1-non-ETS Fusion

Interventions

Type	Name	Description
PROCEDURE	Biospecimen Collection	Undergo blood sample collection
DRUG	Chemotherapy	Given chemotherapy
PROCEDURE	Computed Tomography	Undergo CT or PET/CT
PROCEDURE	Conventional Radiotherapy	Undergo conventional radiotherapy
PROCEDURE	Definitive Surgical Resection	Undergo definitive surgical resection
RADIATION	Dose-escalated Radiation Therapy	Undergo hypofractionated or conventional radiotherapy
OTHER	Electronic Health Record Review	Ancillary studies
RADIATION	External Beam Radiation Therapy	Undergo definitive radiotherapy
RADIATION	Hypofractionated Radiation Therapy	Undergo hypofractionated radiation therapy
PROCEDURE	Magnetic Resonance Imaging	Undergo MRI
PROCEDURE	Positron Emission Tomography	Undergo PET/CT
OTHER	Questionnaire Administration	Ancillary studies
RADIATION	Radiation Therapy	Undergo hypofractionated or conventional standard radiotherapy

Timeline

• Start date: 2025-11-24
• Primary completion: 2029-12-31
• Completion: 2029-12-31
• First posted: 2025-09-23
• Last updated: 2026-01-23

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated device study