This interventional, post-market, multicenter clinical investigation is designed to evaluate the performance of a custom-made medical device, "the Breast Cancer Locator (BCL)" in Subjects with non-palpable breast cancer, in Europe.

The aim of this interventional, post-market, multicenter clinical investigation is to evaluate the performance of a custom-made medical device, the Breast Cancer Locator (BCL) system, in subjects with non-palpable breast cancer. The study will be conducted in European countries. To evaluate the performance of BCL in reducing the positive margin rate, the proportion of patients with positive margins after partial mastectomy with the BCL will be obtained.

Each Subject, after signing an Informed Consent Form (ICF), will enter into a screening phase, during which several assessments (e.g., demographics, medical history, evaluation of available prone MRI and core biopsy pathological results) will be conducted.

At visit 1, the Subject will undergo supine MRI, from which a 3D breast image and BCL will be made.

At visit 2, the patient will undergo Breast Conserving Surgery (BCS) using the BCL system. On the same day, the specimen volume will be determined. The excised specimen will be sent to the pathological lab for analysis. The results, including the positive margin rate (PMR) and specimen mammogram, will be obtained within 14 days.

At visit 3, follow-up assessments (including physical examination, and adverse event review) will be performed.

At the End Of Study visit, adverse events will be assessed and patients will be asked to express their satisfaction with the BREAST-Q.

Inclusion Criteria:

• Patient Informed consent form (ICF) signed
• Female Aged ≥ 18 years at the time of the signature of ICF
• Histologic diagnosis of IBC or DCIS
• Tumor excision that will require localization because it cannot be definitively defined by palpation
• The tumor is unifocal; possible satellite lesions < 2 cm from primary are eligible
• The tumor enhances and is greater than or equal to 5mm on prone breast MRI imaging
• Subject and surgeon agree to perform BCS
• Willingness to follow all study procedures, including attending all site visits, tests and examinations.

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
• Contraindication to use of gadolinium-based intravenous contrast, including life-threatening allergy
• Uncontrolled cardiac, renal, or pulmonary disease
• Uncontrolled systemic disease (e.g., lupus erythematosus or scleroderma)
• Compromised renal function including chronic, severe kidney disease (GFR < 30 ml/min/1.73m2), or acute kidney injury
• Pregnancy or breast-feeding
• 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
• Known allergy to device components
• Multicentric tumors (additional tumors > 2 cm from primary)
• Infectious or inflammatory processes near the area of intervention
• Planned surgery with localization devices including WGL, intraoperative ultrasound guidance, radiofrequency emitting implants, magnetic seeds, radioactive seeds, and tissue inspection devices
• Simultaneous participation in an interventional study or participation in an interventional study in the last 1 month before study inclusion
• Known drug and/or alcohol abuse
• Mental incapacity that precludes adequate understanding or cooperation

There is no plan to share individual participant data to other researchers.

From supine MRI 10-40 days prior to surgery through 6 weeks +/- 7 days post surgery

One possible limitation of the study is the single arm design, which does not allow a comparison of the BCL system with the current standard approaches. A second limitation is the short follow-up period (6-weeks post surgery).