Laser interstitial thermal therapy (LITT) is an emerging clinical treatment for deep brain tumors, which is safe, minimally invasive, and effective. This paper established a three-dimensional model based on the LITT heat transfer model, including brain tissue, laser fiber, and straight tube vessels. Combining the PID control equation, diffuse approximation equation, Pennes heat transfer equation, and Murray’s law, the effect of micro-vessel radius and distance between vessels and fiber on the ablation temperature field during laser ablation was investigated by using COMSOL finite element software. The results showed that at a constant distance of 1 mm between the vessel and the fiber, the vessels with a radius of 0.1–0.2 mm could be completely coagulated, the vessels with a radius of 0.3–0.6 mm had cooling and directional effects on temperature distribution and thermal damage, and the vessels with a radius of 0.7–1.0 mm had cooling effects on the ablation temperature. When the vessel-fiber spacing was raised by 2 mm, 0.3–0.4 mm, vasculature had a directional influence on the temperature field; when the vessel-fiber spacing was raised by 3 mm, only 0.3 mm vessels had a directional effect on the temperature field. The range of temperature field impacted by blood flow diminishes as the distance between the optical fiber and the blood artery grows. The ablation zone eventually tends to be left and right symmetrical. In this study, we simulated the LITT ablation temperature field model influenced by tiny vessels based on PID control. We initially classified the vessels, which provided some guidance for accurate prediction and helped the accuracy of preoperative planning.
Microwave ablation, as an emerging method for treating lung cancer, has been widely used because of its advantages, such as being less invasive and having fewer side effects compared with other therapies, such as surgery and chemotherapy. The key to microwave ablation is to destroy the tumor tissue while minimizing the damage caused to the surrounding healthy tissues. Based on the heat transfer model of porous media, a two-dimensional simulation model of a spherical tumor surrounded by healthy tissue is established in this paper. The effects of tumor diameter, tumor porosity, and microwave ablation power on the highest temperature, ablation area, and volume of the tumor tissue were studied by using the software COMOSL Multiphysics. The results show that the porous heat transfer model is more practical than the Pennes biological heat transfer model. The tumor diameter and the tumor porosity have a great influence on the maximum temperature, the ablation area and volume. In this study, a more realistic model of microwave ablation of lung tumors was established, and the ablation results were predicted accurately, which provided the basic reference data for the selection of clinical therapeutic parameters of microwave ablation of lung tumors. To a certain extent, it can ensure that the ablation area completely covers the tumor and reduces the risk of tumor recurrence, which is of great significance in the accurate treatment of pulmonary tumors by microwave ablation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.