Heat-based cancer treatment, so-called hyperthermia, can be used to destroy tumour cells directly or to make them more susceptible to chemotherapy or radiation therapy. To apply heat locally, iron oxide nanoparticles are injected into the bloodstream and accumulate at the tumour site, where they generate heat when exposed to an alternating magnetic field. However, the temperature must be precisely controlled to achieve therapeutic benefits while avoiding damage to healthy tissue. We therefore present a computational model for nanoparticle-mediated hyperthermia treatment fully integrated into a multiphase porous-media model of the tumour and its microenvironment. We study how the temperature depends on the amount of nanoparticles accumulated in the tumour area and the specific absorption rate of the nanoparticles. Our results show that host tissue surrounding the tumour is also exposed to considerable doses of heat due to the high thermal conductivity of the tissue, which may cause pain or even unnecessary irreversible damage. Further, we include a lumped and a discrete model for the cooling effect of blood perfusion. Using a discrete model of a realistic microvasculature reveals that the small capillaries do not have a significant cooling effect during hyperthermia treatment and that the commonly used lumped model based on Pennes' bioheat equation overestimates the effect: within the specific conditions analysed, the difference between lumped and discrete approaches is approximatively 0.75{\deg}C, which could influence the therapeutic intervention outcome. Such a comprehensive computational model, as presented here, can provide insights into the optimal treatment parameters for nanoparticle-mediated hyperthermia and can be used to design more efficient treatment strategies.

翻译：基于热量的癌症治疗，即所谓的热疗，可用于直接破坏肿瘤细胞或使其对化疗或放射治疗更为敏感。为实现局部加热，将氧化铁纳米颗粒注入血液并在肿瘤部位富集，当暴露于交变磁场时，这些纳米颗粒会产生热量。然而，必须精确控制温度以实现治疗效果，同时避免对健康组织造成损伤。为此，我们提出了一个完全整合到肿瘤及其微环境的多孔介质多相模型中的纳米颗粒介导热疗计算模型。我们研究了温度如何依赖于肿瘤区域累积的纳米颗粒数量以及纳米颗粒的比吸收率。我们的结果表明，由于组织的高热导率，肿瘤周围的宿主组织也会暴露于相当剂量的热量下，这可能引起疼痛甚至不必要的不可逆损伤。此外，我们采用了集总模型和离散模型来描述血液灌注的冷却效应。使用真实微血管系统的离散模型揭示，在热疗过程中，微小毛细血管不具有显著的冷却效果，而基于Pennes生物热方程的常用集总模型高估了该效应：在所分析的特定条件下，集总方法与离散方法之间的温差约为0.75°C，这可能影响治疗干预的结果。如此全面的计算模型，如本文所述，可为纳米颗粒介导热疗的最佳治疗参数提供见解，并可用于设计更有效的治疗策略。