MRI-Conditional Tissue Expanders in Breast Reconstruction: Clinical Outcomes and Radiation Therapy Implications.

Abstract

Background: MRI-conditional tissue expanders (MRI-CTEs) were developed to address imaging artifacts and challenges in radiation planning associated with traditional tissue expanders (TTEs). This study aims to compare the clinical outcomes and radiation protocol impacts of MRI-CTEs versus TTEs in postmastectomy breast reconstruction.

Methods: A retrospective review was conducted on immediate breast reconstruction 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). Demographics, 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, allowing for a reduction in planning target volume margins from 20 mm to 5 mm, improving 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 similar surgical outcomes to 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.