Table 1.

Eligibility/Exclusion Criteria

Eligibility	Exclusion
Age ≥18 years old	Breast micro-calcifications prior to starting radiation treatment (RT)
ECOG performance status of 0–1	> 9 positive axillary or sentinel lymph node
Stage 0–IIIA (pTis-T2, pN0-pN2a, M0) breast cancer	Lobular carcinoma in situ alone or non breast epithelial histology
Systemic treatment (chemotherapy or hormonal therapy) was allowed.	Multicentric disease
Neoadjuvant chemotherapy allowed.	Clinically or radiographically suspicious contralateral regional lymph nodes unless histologically confirmed negative for tumor
Negative margins (no tumor on ink).	Prior treatment for contralateral or synchronous breast cancer or if they had prior RT to the current breast.
	Co-morbid conditions: Paget’s disease Collagen vascular disease Life expectancy <2 years secondary to co-morbidities Psychiatric or addictive disorder that precluded informed consent Malignancy other than non-melanomatous skin cancer < 5 years prior to enrollment
	No documented negative pregnancy test or unwilling to maintain safe and effective birth control