What ‘s the tumor treatment of HIFU piezo ceramic

Views: 1 Author: Site Editor Publish Time: 2018-10-18 Origin: Site

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Different parameters of piezoelectric ceramics can be selected according to the needs of the therapeutic dose at the time of treatment to achieve the best effect. Highly vascularized tumors although clinical exposure times often take more than 3s, early studies have shown that short-term exposure is independent of tissue perfusion, while thermotherapy techniques are greatly affected by tissue perfusion.

The necrotic volume of the tissue in the target area depends on two aspects: (1) therapeutic dose: it is related to the transducer output power, focusing parameters, frequency, single pulse time and total treatment time; (2) characteristics of biology of living tissue: Due to the different structure, density, function, blood supply status and target depth of biological tissues, the propagation speed, absorption and attenuation of ultrasound piezoelectric ceramic in different tissues are different. These multivariate factors make ultrasound therapeutic dosimetry a very complex issue. Second, HIFU clinical application.In the 1950s, HIFU was first used to treat central nervous system diseases (Parkinson's disease). Despite some success, the treatment requires craniotomy and a short-lived effect. This technique was essentially limited to laboratory research in the following decades, and until the 1990s HIFU reappeared as a non-invasive therapeutic instrument. At this time, people have a great interest in the various clinical characteristics they have.

More mature clinical treatment research is prostate cancer. In 1993,HIFU for the first time to treat prostate cancer. Many scholars have studied from different aspects and have achieved gratifying results. Chaussy followed up 184 patients with prostate cancer who were treated. The results showed that the negative rate of biopsy was above 80%, and 97% of patients had low prostate specific antigen. In 2001, French scholar Gelet studied 102 elderly patients with prostate cancer who had lost the opportunity to cure. The average follow-up of HIFU beauty sensor transducer was 19 (3 to 76) months, and the total effective rate was 66%. The change of PSA before and after treatment was statistically significant. The effect is better than radiotherapy. Many scholars such as Japan and the United States have reported HIFU treatment of prostatic hypertrophy. More representatively, in 1999, it is reported in the United States, Canada, and Japan that three clinical centers were used to treat 62 patients with prostatic hypertrophy. HIFU treatment and continuous observation of the results of 1 to 2 years of research confirmed the feasibility and effectiveness of HIFU in the treatment of prostatic hypertrophy.

It is reported that ultrasound guided HIFU ceramic transducer treatment of 37 cases of breast cancer did not cause damage to surrounding normal structures such as skin, pectoralis major and lung tissue, and the positioning was accurate and reliable. thoracic and abdominal metastases were treated, 13 cases of complete necrosis, 5 cases of most necrosis (range > 80%), 12 cases of pain disappeared, the total effective rate of HIFU was 100%, only a few cases I degree burns occurred, and 1 case of perforation occurred, which was related to the treatment of prone position. Which conducted a small sample (4 cases) of HIFU piezo with radiotherapy and chemotherapy for testicular cancer, and concluded that HIFU combined with radiotherapy and chemotherapy for testicular cancer is a safe and feasible treatment for minimally invasive and preserved organs. However, due to the small number of cases, it is still necessary to further explore the treatment mode and prevention of complications.

In 2000, Vaezy al first use 7Mhz HIFU piezo transducer for the treatment of nude mice model of uterine fibroids. The tumor volume was reduced by 91% on average within 1 month after treatment, which was significantly different from the placebo group. other uterus studies of 20 cases of HIFU after surgical resection showed that HIFU can focus on irradiating human uterine leiomyoma cells to cause irreversible coagulative necrosis, which not only to kill tumors in vitro, but also to living fibroids. It has a certain anti-tumor effect and is expected to become a widely accepted non-invasive new technique for the treatment of uterine leiomyoma.HIFU is applied 869 patients' treatment results, including 26 kinds of tumors such as liver cancer, breast cancer, malignant bone tumor and soft tissue tumor. The results showed that it had obvious curative effect on malignant solid tumor, uterine fibroids and prostate disease in pelvic and abdominal cavity. There is no serious complications were found in the study of in vitro HIFU treatment of malignant tumors. It was found that the temperature rise of the tumor target area was lowered due to the large attenuation of sound energy. Although this temperature rising and the duration of time were insufficient to cause coagulative necrosis of tumor tissue, it played a role in inhibiting tumor growth and delaying death. Therefore, when is evaluating the effect, it is not possible to judge simply by the size of the tumor, but to judge the survival or the state of being killed. It is believed that the effects and prognosis of piezo ceramics for laser machine are different due to factors such as different disease types, growth patterns, stages, and systemic conditions, and the evaluation criteria are not unique. Establishing a correct and perfect evaluation system requires exploration in the long-term work in the future.