PROMISE-005: A Phase II Randomized Study Assessing the Efficacy of Stereotactic Body Radiotherapy (SBRT) in Patients With Oligometastatic Breast or Lung Cancer

Radiation to each metastatic site should be delivered to a minimum dose of 30 Gy in 5 fractions (BED of 48 Gy10). The exact dose of radiotherapy will be determined by the treating radiation oncologist. Preferred regimens for lung metastases include 50 Gy in five fractions, 48 Gy in four fractions, or 54 Gy in three fractions, although lower doses may be employed to respect dose limits to critical structures such as the esophagus. Recommended SBRT dosing for other sites includes 27 to 30 Gy in three fractions or 24 Gy in one fraction for bone metastases.

Standard of care systemic therapy, including chemotherapeutics, targeted therapies, immunomodulatory agents, and hormonal therapies will be delivered at the discretion of the treating oncologist. For patients randomized to receive SBRT, systemic therapy can be continued during SBRT at the discretion and concensus of treating physicians (medical oncologist and radiation oncologist). If the treating physicians recommend discontinuing systemic therapy during SBRT, general guidelines for stopping and reinitiating systemic regimen are as follows: Hormonal therapies and immunotherapy can be continued during SBRT. Consideration can be given to holding cytotoxic chemotherapy beginning 3 to 7 days prior to the initiation of SBRT until 3 to 7 days after the completion of SBRT. Similarly, consideration can be given to holding biologic agents during SBRT and for 0 to 3 days before and after.