New histological diagnosis of invasive carcinoma of the breast, grade I or II, estrogen and progesterone receptor (ER and PR) positive, HER2 negative on needle biopsy and limited to Stage I (T1 N0 M0) on clinical and radiological assessment with MRI of the breasts and axillary ultrasound;
Candidate for breast conserving surgery;
Signed study consent form completed prior to study entry.
You may not be if
Breast cancer with disease within 5 mm from skin or chest wall;
Previous or concomitant invasive malignancies treated within 5 years of study entry;
Serious non-malignant disease (cardiovascular, pulmonary, systemic lupus or scleroderma), which would preclude to definitive radiation therapy;
Psychiatric disorders, which would preclude from obtaining informed consent
