Nanoparticle enhanced coupled bioheat vapor bubble model and simulation for LITT in breast tumors

Laser-Induced Thermotherapy (LITT) efficacy hinges on achieving localized heating and controlled vaporization within tumor tissue. Building upon our previously developed fully-coupled bioheat vapor bubble model, this study integrates gold nanoparticles (GNPs) to enhance optical absorption and bubble dynamics during LITT of breast tumors. Gold nanoparticles (spherical, ~ 60 nm diameter) were considered to enhance optical absorption and bubble dynamics. We introduce an additional heat-source term, \(\:{Q}_{NP}={\mu\:}_{NP}{I}_{0}{C}_{NP}\), to the Pennes bio heat equation, where \(\:{\mu\:}_{NP}\) ​and \(\:{C}_{NP}\) denote the nanoparticle absorption coefficient and concentration. Latent-heat effects and Rayleigh Plesset bubble dynamics are retained from the baseline model. Simulations were carried out for fluences of 30–80 J/cm² using an 800 nm near-infrared (NIR) Gaussian laser beam, applied as a 50 ms square pulse .Through simulations comparing nanoparticle rich (\(\:1\:\times\:1{0}^{10}\) particles/mL) and nanoparticle free scenarios across laser fluences of \(\:30-80\:\text{J}/\text{c}{\text{m}}^{2}\), our results show that GNPs reduce vaporization threshold fluence by approximately 20%, increase peak temperature by ~ 15 \(^\circ \text{C}\) and elevate peak bubble radius from ~ 12 μm to ~ 18 μm. Sensitivity analyses reveal significant dependencies of necrotic zone size on nanoparticle parameters. This nanoparticle-enhanced model offers a powerful theoretical framework for optimizing LITT protocols, potentially reducing required laser doses and minimizing collateral damage.