High-intensity focused ultrasound (HIFU) is a non-invasive therapeutic modality that uses precise acoustic energy to ablate cancerous tissues through coagulative necrosis. In this context, we investigate the efficacy of HIFU ablation in two distinct cellular configurations, namely 2D monolayers and 3D spheroids of epithelial breast cancer cell lines (MDA-MB 231 and MCF7). The primary objective is to compare the response of these two in vitro models to HIFU while measuring their ablation percentages and temperature elevation levels. HIFU was systematically applied to the cell cultures, varying ultrasound intensity and duty cycle during different sonication sessions. The results indicate that the degree of ablation is highly influenced by the duty cycle, with higher duty cycles resulting in greater ablation percentages, while sonication duration has a minimal impact. Numerical simulations validate experimental observations, highlighting a significant disparity in the response of 2D monolayers and 3D spheroids to HIFU treatment. Specifically, tumor spheroids require lower temperature elevations for effective ablation, and their ablation percentage significantly increases with elevated duty cycles. This study contributes to a comprehensive understanding of acoustic energy conversion within the biological system during HIFU treatment for 2D versus 3D ablation targets, holding potential implications for refining and personalizing breast cancer therapeutic strategies.
高强度聚焦超声（HIFU）是一种非侵入性治疗手段，通过精确的声能引发凝固性坏死以消融癌组织。本研究探讨了HIFU在两种不同细胞构型——即二维单层培养与三维球体培养的乳腺上皮癌细胞系（MDA-MB 231和MCF7）中的消融效果。主要目标在于比较这两种体外模型对HIFU的响应差异，同时测定其消融率与温升水平。研究系统地对细胞培养体系施加HIFU处理，在不同超声辐照时段中调整超声强度与占空比参数。结果表明，消融程度受占空比影响显著，较高占空比可产生更高消融率，而超声辐照时长的影响较小。数值模拟验证了实验观察结果，凸显出二维单层与三维球体对HIFU治疗的响应存在显著差异。具体而言，肿瘤球体在较低温升条件下即可实现有效消融，且其消融率随占空比升高显著增加。本研究深化了对HIFU治疗中二维与三维消融靶标生物体系内声能转换机制的理解，为优化和个性化乳腺癌治疗策略提供了潜在参考依据。
肿瘤(癌症)患者之家