Intensity Modulated Radiotherapy (IMRT) vs. 3D-conformal Accelerated Partial Breast Irradiation (APBI) for Early Stage Breast Cancer After Lumpectomy

Inclusion Criteria

• •Histologically confirmed disease (AJC Classification): Tis, T1, T2 (≤ 3.0 cm), N0, M0.
• •Microscopic multifocal disease is only allowed when the entire span of identified disease measures 3.0 cm or less.
• •Negative surgical margins ( ≥ 0.2 cm) after final surgery.
• •Subjects with infiltrating lobular histologies or high nuclear grade DCIS will be required to have breast MRI scanning as part of the initial staging to verify localized disease.
• •Subjects with DCIS will be included in the study only if they had an MRI prior to lumpectomy.
• •Findings on MRI scanning revealing relevant suspicion of disease outside of planned lumpectomy volume should be further evaluated by ultrasound and, if necessary biopsy, to exclude multicentric/multifocal disease.
• •Subjects with malignant calcifications on mammography will be required to have repeat mammography after surgery to ensure removal of all malignant calcifications.
• •Willing to complete additional screening requirements and meet eligibility criteria as defined in protocol Sec. 4.4.
• •Successful placement of fiducial markers for IGRT requiring nonmigrating fiducials.
• •PTV to ipsilateral breast ratio (IBR) ≤ 25 %.
• •Radiotherapy anticipated to begin within 10 weeks of lumpectomy or re-excision of margins.