Magnetic Resonance Imaging-Conditional Tissue Expanders in Breast Reconstruction: Clinical Outcomes and Radiation Therapy Implications.

Abstract

Background: Magnetic resonance imaging-conditional tissue expanders (MRI-CTEs) were developed to address imaging artifacts and challenges in radiation planning associated with traditional tissue expanders (TTEs). This study compared the clinical outcomes and impact of radiation protocols of MRI-CTEs and TTEs in postmastectomy breast reconstruction.

Methods: A retrospective review was conducted of immediate breast reconstruction performed with MRI-CTEs or TTEs between 2021 and 2024. Outcomes, such as seroma, infection, malposition, and expander loss, were analyzed.

Results: A total of 867 tissue expanders were evaluated in 559 patients. The MRI-CTE cohort consisted of 103 patients (161 devices), and the TTE cohort included 456 patients (706 devices). Demographic characteristics, surgical details, and outcomes did not differ significantly, including seroma ( P = 0.091), malposition ( P = 0.827), and mastectomy skin flap necrosis ( P = 0.251). Three cases (1.9%) in the MRI-CTE cohort required MRI evaluation but did not require explantation. The MRI-CTE group had a lower need for artifact management during radiation therapy and reduced imaging artifact size from 4 cm to 1 cm in diameter. This allowed for a reduction in planning target volume margins from 20 mm to 5 mm, which improved delineation accuracy by 75% and decreased irradiation of healthy tissue by up to 60%.

Conclusions: MRI-CTEs may contribute to improved clinical outcomes, with fewer surgical interventions and enhanced precision in radiation treatment planning. MRI-CTEs demonstrated surgical outcomes similar to those for TTEs, but offered improved accuracy in radiation dose calculations. Reduced manual interventions for artifact adjustment decrease the potential for human error, enhancing the overall precision of radiation treatment delivery.

Clinical question/level of evidence: Therapeutic, III.