3DCRT	3D conventional radiation therapy
BCS	breast conserving surgery
BID	twice daily
BT	brachytherapy
CTx	chemotherapy
DCIS	ductal carcinoma in situ
e-	electrons
EBRT	external beam radiotherapy
EP	endpoint
ER	estrogen receptor
ET	endocrine therapy
FU	follow-up
IBC	invasive breast cancer
IDC	invasive ductal cancer
IBTR	in breast tumor recurrence
IMRT	intensity modulated radiation therapy
IORT	intraoperative radiotherapy
HR+	hormone receptor positive
LR	local recurrence
Med.	median
n	number
N+	nodal positive
Noninf	non-inferiority
n.r.	not reported
PBI	partial breast irradiation
Pop	Population
QD	once daily
RT	radiotherapy
q.o.d.	every other day
Stat.	statistical
Strat.	stratification
WBI	whole breast irradiation
x	photons
y	years