Abstract:Heat is the product following the metabolism of cells, and the metabolism is closely related with the pathological information of living organism. So, there are strong ties between the heat distribution and the pathological state in living organism. In this paper, the mathematical function δ is introduced in the classical Pennes bio-heat transfer equation as the point heat source. By simplifying the boundary conditions, a novel bio-heat transfer model is established and solved in a spherical coordinate system. Based on the temperature distribution of human body surface, the information of heat source is mined layer by layer, and the corresponding q-r curve of heat intensity varying with depth is acquired combining the fitting method of Lorentz curve. According to a large number of clinical confirmed cases and statistics, the diagnostic criteria judging diseases by q-r curve are proposed. Five typical clinical practices are performed and four of the diagnosis results are very consistent with those of molybdenum target (MT) X-ray, B-ultrasonic images and pathological examination, one gives the result of early stage malignant tumor that MT X-ray and B-ultrasonic can't check out. It is a radiation-free green method with noninvasive diagnostic procedure and accurate diagnosis result.

This study aims to evaluate the feasibility and efficacy of quantitative diagnosis through thermal analysis of abnormal metabolism. In this paper, an analytical-based steady-state solution for the thermal inverse problem was developed, considering an equivalent point heat source embedded in the tissue. Based on this solution, we developed a simple and efficient algorithm that generates solutions for the nonlinear heat conduction model. Using the nonlinear fitting analysis, a regular distribution can be derived from the raw thermal patterns of the skin surface above the tumor, and the power and depth of the equivalent heat source can be derived to investigate whether the tumor is malignant or benign. The thermal power Q of internal heat source was estimated to predict the satisfactory approaches to distinguish between benign and malignant tumors. The results of four clinical cases (female patients with malignant tumor and benign tumor) show that the estimated values of the power of the heat sources in malignant cases (fatty: Q = 0.34851 W; dense: Q = 0.46933 W) are both far greater than the ones in benign (fatty: Q = 0.04721 W; dense: Q = 0.07717 W), irregardless of the breast density. The correlation coefficients (R (2)) of the nonlinear curve fittings are all above 0.98. The new thermal method proposed in this study would help to improve the preciseness of diagnosis on breast masses (malignant or benign).

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Immunotherapy is playing an increasingly important role in the treatment of tumors. Different from the traditional direct killing or excision therapies, immunotherapy depends on autologous immunity to kill tumor cells and tissues by activating or enhancing the body’s immune system. Large numbers of recent studies suggest that low-frequency HIFU can not only enhance the intensity of the body’s anti-cancer immune response, but also improve the efficiency of immunotherapy drug delivery to strengthen the effects of tumor immunotherapy. The focused ultrasound (FUS) destructs the tumor and simultaneously generates tumor debris and tumor-associated antigens, which enhances the immunogenicity of the tumor and stimulates the immune cells, inducing the body’s immune response. Microbubbles are clinically used as a contrast. As a matter of fact, the addition of microbubbles can reinforce the destructive effect of FUS on the tumor and activate a stronger immune response. The combined application of ultrasound and microbubbles can more effectively open the blood brain barrier (BBB), which is beneficial to improving the intake of immune cells or immunotherapy drugs and exerting a positive influence in the lesion area. Currently, microbubbles and nanoparticles are commonly used as gene and drug carriers. Using ultrasound, the immune-related gene or antigen delivery itself can enhance the immune response and improve the efficacy of the immunotherapy.