3.3.6 Local Hyperthermia for Hepatocellular Carcinoma

3.3.6 Local Hyperthermia for Hepatocellular Carcinoma

Local hyperthermia for hepatocellular carcinoma has developed into four types: laser-induced thermotherapy (LITT), microwave coagulation therapy (MCT), radiofrequency thermal ablation (RFA), and high-intensity focused ultrasound (HIFU). LITT is currently the most extensively studied and clinically proven method. It involves using imaging technologies (ultrasound, CT, MRI, etc.) to guide laser probes (which can be multiple) to convert light energy into heat, continuously heating the hepatocellular carcinoma tissue to a specific temperature until it coagulates and necrotizes (typically extending 0.5–1.0 cm beyond the tumor boundary), while sparing the surrounding normal liver tissue [61]. Christophi et al. [62] used neodymium-doped yttrium-aluminum garnet (Nd:YAG) lasers to treat patients with unresectable liver metastases, achieving an average survival time of 24.6 months and a 5-year survival rate of 3.8%. MCT utilizes microwave radiation to excite charged ions, water, and polar molecules such as proteins in the tissue, causing polarization and vibration under the influence of an alternating electric field, generating intense heat that leads to coagulation and necrosis of the tumor tissue, thereby achieving in-situ inactivation and local radical cure. Seki et al. [62] employed laparoscopic MCT for liver cancer, which was precisely localized and minimally invasive, resulting in a complete tumor clearance rate of 87.5% and a 3-year survival rate of up to 92%. Recent studies have shown that, in addition to its thermal coagulation effect, MCT also enhances the body’s immune function. Wu Mengchao et al. [ ] believe that microwave therapy is particularly suitable for patients with severe cirrhosis and small liver cancers that are not amenable to surgical resection.

Radiofrequency thermal ablation is divided into radiofrequency thermal ablation (RFA) and radiofrequency capacitive heating. RFA involves passing high-frequency alternating current through the tumor tissue, where ions in the tissue surrounding the electrode constantly change direction under the influence of the alternating current, generating frictional heat and creating localized high temperatures that cause water in the tissue to vaporize and proteins to denature, ultimately leading to coagulative necrosis. The latter method places the heat source outside the body to raise the lesion temperature to 41°C–45°C. Although this approach makes it difficult to achieve the ideal treatment temperature throughout the entire tumor area, it is non-invasive and well-tolerated by patients, so it is often used in combination with other methods. High-intensity focused ultrasound (HIFU) is a low-trauma, cutting-edge technology that can both precisely target and instantly generate high temperatures, characterized by safety, effectiveness, and feasibility. However, due to the obstruction of the human ribs to ultrasound waves and limitations in ultrasound localization, its clinical application is still being explored [64]. HIFU does not require puncture and, compared with other therapies, is a less invasive technique, making it more suitable for patients who are not candidates for surgery.

In recent years, with the development of medical immunology and molecular biology, the diagnosis and treatment of hepatocellular carcinoma have greatly improved. However, due to its insidious onset and poor prognosis, the therapeutic outcomes remain unsatisfactory. Traditional Chinese medicine, with its multi-pathway, multi-target approach, low toxicity, preventive effects before disease onset, and ability to prevent disease progression once it occurs, has increasingly gained popularity and been applied clinically. This experiment aims to establish a mouse model of H22 hepatocellular carcinoma to observe the expression of VEGF and p53 in tumor tissues under the influence of Pei’s Soft Liver and Anti-Flatulence Pill, thereby exploring the anti-tumor mechanism of Pei’s Soft Liver and Anti-Flatulence Pill at the microscopic level.

Experimental Study