Breast-Conserving Surgery After Neoadjuvant Chemotherapy Guided by a Supine Magnetic Resonance Imaging Projection...

Area of Science:

• Oncology
• Radiology
• Surgical Oncology

Background:

• Neoadjuvant chemotherapy (NAC) can make it challenging to locate the original tumor site for breast-conserving surgery (BCS).
• Accurate identification of residual cancer is crucial for pathological response and maintaining breast cosmesis after BCS.

Purpose of the Study:

• To identify magnetic resonance imaging (MRI) findings that enable precise tumor removal in BCS after NAC using an MRI projection mapping system (PMS).
• To assess if MRI-PMS can facilitate BCS without additional margins, preserving normal breast tissue.

Main Methods:

• 36 women with breast cancer underwent contrast-enhanced MRI before NAC and supine unenhanced MRI with skin markers after NAC.
• An MRI projection mapping system (PMS) projected a maximum intensity projection image of the tumor extent before NAC and skin markers onto the breast for BCS.
• Clinical, pathological, and MRI findings were compared between patients who required additional margins and those who did not.

Main Results:

• 19 out of 36 patients (52.8%) did not require additional margins for BCS using MRI-PMS.
• Patients without additional margins showed a higher tumor diameter reduction rate and a lower signal ratio between the tumor bed and normal tissue after NAC.
• MRI-PMS allowed BCS without additional margins in a significant portion of patients.

Conclusions:

• MRI-PMS is effective in guiding breast-conserving surgery (BCS) after neoadjuvant chemotherapy (NAC), enabling tumor removal without additional margins.
• Predictive MRI findings, such as greater tumor diameter reduction and lower post-NAC tumor bed signal ratio, are associated with successful margin-negative BCS.
• This technique holds potential for conserving normal breast tissue and improving cosmetic outcomes in breast cancer patients undergoing NAC and BCS.