A Pilot Study of the Impact of Microwave Ablation on the Dielectric Properties of Breast Tissue

Abstract

Percutaneous microwave ablation (MWA) is a promising technology for patients with breast cancer, as it may help treat individuals who have less aggressive cancers or do not respond to targeted therapies in the neoadjuvant or pre-surgical setting. In this study, we investigate changes to the microwave dielectric properties of breast tissue that are induced by MWA. While similar changes have been characterized for relatively homogeneous tissues, such as liver, those prior results are not directly translatable to breast tissue because of the extreme tissue heterogeneity present in the breast. This study was motivated, in part by the expectation that the changes in the dielectric properties of the microwave antenna’s operation environment will be impacted by tissue composition of the ablation target, which includes not only the tumor, but also its margins. Accordingly, this target comprises a heterogeneous mix of malignant, healthy glandular, and adipose tissue. Therefore, knowledge of MWA impact on breast dielectric properties is essential for the successful development of MWA systems for breast cancer. We performed ablations in 14 human ex-vivo prophylactic mastectomy specimens from surgeries that were conducted at the UW Hospital and monitored the temperature in the vicinity of the MWA antenna during ablation. After ablation we measured the dielectric properties of the tissue and analyzed the tissue samples to determine both the tissue composition and the extent of damage due to the ablation. We observed that MWA induced cell damage across all tissue compositions, and found that the microwave frequency-dependent relative permittivity and conductivity of damaged tissue are lower than those of healthy tissue, especially for tissue with high fibroglandular content. The results provide information for future developments on breast MWA systems.

A Preliminary Study of Ultrasound-Guided Microwave Ablation for Nonpuerperal Mastitis Treatment

“…Treatment of NPM by US-guided MWA directly inactivates the protein in inflammatory lesions by applying a high temperature and coagulates necrotic tissue. It has the advantages of a short treatment time and a rapid effect [32,33]. US guidance is used to estimate the ablation range.…”

Memenin fibroadenomlarına uygulanan mikro dalga ablasyon tekniği ile erken dönem tedavi yanıtlarının değerlendirilmesi

“…These treatments affect not only the tumor but also the adjacent breast and adipose tissue. [3] Yang et al [1] applied 755 MWA procedures to a series of 440 patients and reported 100% success rates. The volume response rate was 78.8% in the 6 th month follow-up, and 97.9% in the 12 th month.…”

Técnicas de ablación como tratamiento en pacientes con cáncer de mama

“…El tumor absorbe la energía, e induce los efectos citotóxicos del calor, lo que resulta en la desnaturalización de proteínas y la necrosis de la coagulación. Los resultados de la MWA mamaria muestran una reducción en el volumen y la palpabilidad de las lesiones y resultados cosméticos satisfactorios (Neira et al, 2020).…”