BBB	blood–brain barrier
BTB	blood–tumor barrier
CDK	cycline-dependent kinase
CI	confidence interval
CNS	central nervous system
CR	complete response
ER	estrogen receptor
HER2	human epidermal growth factor receptor 2
HR	hazard ratio
iCBR	intracranial clinical benefit rate
iORR	intracranial objective response rate
OS	overall survival
PARP	poly (ADP-ribose) polymerase
PFS	progression-free survival
PI3K	phosphoinositide 3-kinase
PR	partial response
RECIST 1.1	Response Criteria in Solid Tumors 1.1
SD	stable disease
SRS	stereotactic radiosurgery
TKI	tyrosine kinase inhibitor
TNBC	triple-negative breast cancer
WBRT	whole-brain radiation therapy