Are the American Society for Radiation Oncology Guidelines Accurate Predictors of Recurrence in Early Stage Breast Cancer Patients Treated with Balloon-Based Brachytherapy?

Table 1

American Society for Radiation Oncology (ASTRO) guidelines.

Characteristic	ASTRO CS grouping
	Suitable	Cautionary	Unsuitable
Age, y	≥60	50–59	<50
Tumor size, cm	≤2	2.1–3.0	>3
T stage	T1	T0 or T2	T3-T4
Histology	Invasive ductal or other favorable subtypes	Invasive lobular or DCIS ≤ 3 cm	DCIS > 3 cm
ER status	Positive	Negative	NA
Grade	Any	NA	NA
Margins	Negative (≥2 mm)	Close (<2 mm)	Positive
Multifocality, cm	≤2	2.1–3	>3
Multicentricity	Unicentric	NA	Present
LVI	None	Limited/focal	Extensive
EIC	None	Yes and tumor size ≤ 3 cm	Yes and tumor size > 3 cm
Nodal status	Negative	NA	Positive
Nodal surgery	SLNB or ALND	NA	None performed
BRCA 1/2 mutation	Not present	NA	Present
Neoadjuvant therapy	Not allowed	NA	Used

CS: consensus statement, DCIS: ductal carcinoma in situ, ER: estrogen receptor, LVI: lymphovascular invasion, EIC: extensive intraductal component, SLNB: sentinel lymph node biopsy, and ALND: axillary lymph node dissection.