Breast cancer is the top one incidence of cancer in women. Whole breast radiation therapy plays an indispensable role in the course of breast cancer treatment, and the radiation dermatitis is the major side effect affected quality of life. Radiation dermatitis can be divided into acute and chronic. Severe acute radiation dermatitis affects the quality of life of patients during the course of treatment, and may cause treatment interruption and affect the efficacy. Chronic radiation dermatitis may cause irreversible skin problems, and lead to so-called "radiation-irritated skin" (radiation-irritated skin) seriously affects the quality of life of breast cancer patients after treatment.

This study will enroll 30 breast cancer patients who received whole breast radiation therapy after breast conserving surgery. Subject will receive FR-101 chest dressing and be instructed to use the product on the target skin area accepted radiation therapy once every 2 days, taking care of avoiding applications from 1 to 4 h before treatment to prevent "Build-up" effect.

Subjects will need to come back to clinics for assessment weekly during radiotherapy, 2 weeks after radiotherapy, and 6 weeks after radiotherapy. The evaluation includes physical examinations, questionnaire surveys, skin observation and measurements, and photographs. The total study time is at least 3 months. The target area of radiation-irritated skin condition will be observed and graded according to CTCAE rate. The skin physiological parameters will be detected by MoistureMeter SC, Vapometer, SkinColorCatch and HX-YL001 infrared thermometer.

Statistical analysis of skin physiological parameters is used to evaluate the efficacy of FR-101 chest dressing on the prevention of acute radiation dermatitis after radiotherapy.

Inclusion Criteria:

• Participants must be males or non-pregnant females at least 20 years of age.
• Diagnosis of non-inflammatory breast adenocarcinoma or in situ breast cancer which were treated by operation with or without adjuvant or neoadjuvant hormonal treatment.
• Patients were scheduled to receive five sessions of radiotherapy per week (1 session per day) for at least four weeks using standard irradiation fraction (with at least 1.8 Gy per session) for total dose of at least 45 Gy or hypofraction irradiation fraction(with 2.66 Gy per session) for total dose of at least 42.56 Gy.
• Participant must give informed consent.

Exclusion Criteria:

• Bilateral breast cancer
• Previous radiotherapy to the chest
• Chemotherapy concurrent with radiation treatment
• Prior breast reconstructions, implants, and/or expanders
• Known radiosensitivity syndromes (e.g. Ataxia-telangiectasia)
• Collagen vascular disease, vasculitis, unhealed surgical sites, breast infections or systemic lupus erythematosus (SLE)
• Participation in any clinical trial in the prior 30 days from baseline.
• Any condition that, in the judgement of the investigator could impose hazards to the patient if study therapy is initiated or affect the participation of the patient in the study.