Table 1.

Eligibility Criteria

Inclusion Criteria

Exclusion Criteria

• 21–80 years old patients • Radiological confirmed brain metastases (4–25 lesions) • Histologically proven malignancy • ECOG performance status ≤2 • Maximum lesion or cavity size ≤5 cm  o For patients with large (≥3 cm) lesions, a neurosurgical consult is recommended due to the increased risk of cerebral oedema  o If brain surgery or other invasive procedures are performed, the treatment should begin at least 2-weeks post-procedure • Life expectancy of at least 6 months • Negative serum pregnancy test within 14 days prior to registration for women of childbearing potential • Women of childbearing potential and male participants who are sexually active must agree to use a medically effective means of birth control throughout protocol treatment • Not suitable for or does not want SRS • Agrees to be randomised to either HA-WBRT or HA-SIB-WBRT

• Prior whole brain radiotherapy. o Prior SRS is not an exclusion. Details of treatment must be recorded. • Diffuse leptomeningeal disease • Extensive extracranial disease, not controlled by systemic treatment • Major medical or psychiatric illness, which in the investigator’s opinion would interfere with the completion of therapy and follow up • Dementia, ongoing psychotic episodes or moderate-severe depression (PHQ-9). • Recent stroke in the past 3 months • Symptomatic brain metastases limiting ADLs • Rapid progression of brain lesion • Patients unable to give informed consent • Total tumour planning target volume (PTV) > 60 cc • Radiological evidence of hydrocephalus • Contraindication to Gadolinium contrast-enhanced MRI brain • Patients with diagnoses of small cell carcinoma, lymphoma or primary brain tumour