Radiosurgery With or Without Whole Brain Radiation for Multiple Metastases

"SRS or hypofractionated stereotactic radiation delivered via the Leksell Gammknife Perfexion/Icon radiosurgery system. Hypofractionated stereotactic radiotherapy 25-32.5 Gy in 5 fractions or 24-27 Gy in 3 fractions at the discretion of the radiation oncologist~Maximum diameter of metastasis (doses in single fraction):~≤ 2 cm: 15-20 Gy \> 2 cm and ≤ 3 cm: 15-18 Gy \> 3 cm and ≤ 4 cm: 15 Gy~Tumour location (doses in single fraction):~Brainstem: 15 Gy~Hypofractionated stereotactic radiotherapy 25-32.5 Gy in 5 fractions may be used for lesions \> 2 cm at the discretion of the radiation oncologist~Note: SRS dosing reduced by 20% (for all prescriptions \> 15 Gy) when patient is randomized to SRS + WBRT arm"

WBRT 20 Gy in 5 fractions or 30 Gy in 10 fractions at the discretion of the radiation oncologist