Accelerated Partial Breast Irradiation With IMRT in Early Breast Cancer

A Multicenter Phase Ⅱ Prospective Clinical Trial of Accelerated Partial Breast Irradiation With IMRT After Breast-conserving Surgery in Early Breast Cancer

This study is to evaluate the efficacy and toxicity of accelerated partial breast irradiation (ABPI) with intensity modulated radiation therapy (IMRT) in low-risk breast cancer treat with breast-conserving surgery.

This study is a national multicenter phase II prospective clinical trial to enroll low-risk breast cancer treat with breast-conserving surgery. All eligible patients will receive ABPI to a total dose of 40Gy, in 10 fractions, 4Gy/fx/day, within 2 weeks. Intensity modulated radiation therapy (IMRT) technique is used. During Follow up, the locoregional recurrence,survival,acute and late adverse events,and quality of life will be prospectively evaluated.

Inclusion Criteria:

• Life Expectation: > 5 years
• Enrollment date no more than 12 weeks after breast-conserving surgery or no more than 8 weeks after adjuvant chemotherapy
• Histologically confirmed diagnosis of invasive ductal carcinoma (grade 1-2), or mucinous carcinoma, or papillary carcinoma, or tubular carcinoma, or medullary carcinoma: primary tumor ≤ 3.0cm in maximum diameter and pN0; or histologically confirmed DCIS: primary tumor ≤ 2.5cm in maximum diameter, low-medium grade
• Unifocal tumour (confirmed by diagnostic MRI)
• No lymphovascular invasion
• ER positive (defined as medium-strongly nuclear staining in >1% of the cancer cells)
• Negative radial resection margins of >= 2 mm
• Surgical clips placed in the tumor bed
• Written informed consent.

Exclusion Criteria:

• Stage Ⅱ-Ⅲ
• Multifocal tumors
• Histologically confirmed diagnosis of invasive ductal carcinoma (grade 3), invasive micropapillary carcinoma, carcinoma of lobular in situ, invasive lobular carcinoma
• Paget's disease of the nipple
• Underwent oncoplastic surgery of ipsilateral breast
• Underwent neoadjuvant chemotherapy or hormonal therapy
• Previous or simultaneous contralateral breast cancer
• Undergone ipsilateral chest wall radiotherapy
• Active collagen vascular disease.