Inclusion Criteria:

1. Woman with histologically confirmed breast cancer who underwent lumpectomy and
requires adjuvant radiation therapy with 2 Gy/fx to a total dose of 50 Gy.

2. Women who received neoadjuvant or adjuvant chemotherapy are eligible for the study.
Three weeks is the minimal interval between chemotherapy and start of radiation
therapy.

3. Patient able to understand the study designed and cooperate with instructions of use.

4. Patient able to sign informed consent

Exclusion Criteria:

1. Woman with lactose allergy (lactose intolerance are eligible)

2. Woman with known connective tissue disorder

3. Woman with uncontrolled diabetes

4. Patients receiving radiation protocol with 2.64 Gy/fx or 1.8 Gy/fx

5. Woman who is unable to sign an informed consent