Randomized Trial of Accelerated Partial Breast Irradiation

A Phase II Randomized Clinical Trial of Accelerated Partial Breast Irradiation Compared With Whole Breast Irradiation With IMRT in Early Breast Cancer

This study is to compare radiation toxicity of accelerated partial breast irradiation (ABPI) with whole breast irradiation (WBI) in low-risk breast cancer.

This study is a single-center phase II randomized clinical trial to enroll low-risk breast cancer treat with breast-conserving surgery. All eligible patients are randomized to receive either ABPI (40Gy/10fx/2wks) or WBI(43.5Gy/15fx/3wks). Intensity modulated radiation therapy (IMRT) technique is used. Grade 2 or more acute and late toxicities are prospectively evaluated and compared.

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.