Breast Cancer Locator Guided vs. Wire Localized Partial Mastectomy for Breast Cancer

Inclusion Criteria: * Female gender * Age \> 18 years * Histologic diagnosis of invasive breast cancer or DCIS * The surgeon determines that pre-operative tumor localization is required because the tumor cannot be definitively detected by palpation * The tumor is unifocal or multifocal with satellite lesions \< or = 2 cm from primary tumor * The tumor enhances on prone breast MRI imaging * The tumor is ≥ 1 cm in diameter on prone breast MRI * Subject and surgeon agree to perform BCS * Subject voluntarily provides informed consent Exclusion Criteria: * Absolute contraindication to MRI, including presence of implanted electrical device (e.g., pacemaker or neurostimulator), aneurysm clip, or metallic foreign body in or near eyes * Severe claustrophobia that precludes prone or supine MRI * Contraindication to use of gadolinium-based intravenous contrast, including life- threatening allergy * Compromised renal function including chronic, severe kidney disease (GFR \< 30 ml/min/1.73m2), or acute kidney injury * Pregnancy - In women of childbearing potential, a urine pregnancy test will be performed * Subjects who have received or plan to receive neoadjuvant chemotherapy * Sternal notch to nipple distance of \> 32 cm as measured in a sitting or standing position * Measurement of widest circumference around breasts and arms \> 135 cm for sites using 60cm bore scanners, and measurement of widest circumference around breasts and arms \>145 cm for sites using 70 cm bore scanners * Su…