Evaluation Of Efficiency And Affecting Factors Of Radiofrequency Ablation Guided By Sonography In Hepatic Malignant Tumors

Hepatic malignant tumors including primary liver cancer and metastatic liver cancer. Primary liver cancer is one of common malignant tumors of the digestive system, China is a high incidence area of the world. Metastatic liver cancer often Comes from gastrointestinal cancer.Primary liver cancer patients with early onset occult may not have any typical symptoms and signs,so most patients have advanced at the time of diagnosis or symptoms.The proportion of patients able to achieve radical resection of only 20% to 30%.After conventional surgical resection liver cancer, 5-year survival rate of approximately 20% to 50%, while patients with tumor diameter of less than 5cm, the 5-year survival after surgical resection increased significantly, about 60% to 70%. Currently the preferred method and the most effective clinical treatment of liver cancer is still hepatectomy.If unable to radical resection, the prognosis is poor. In poorly differentiated highly malignant liver cancer cells, however, is not sensitive to radiotherapy and chemotherapy and ineffective. Therefore, clinicians more and more attention of various minimally invasive treatments.For those with unresectable hepatocellular carcinoma increased use of minimally invasive treatment.In recent years, minimally invasive method for the local treatment of liver cancer have been carried out in clinical, include: Radiofrequency ablation(RFA), high intensity focused ultrasound(HIFU), via the hepatic artery or portal vein embolization, microwave freeze, ethanol injection therapy.And radiofrequency ablation of liver cancer is relatively mature and curative minimally invasive treatment.RFA is recognized as the world's anti-tumor larger, lighter body injury minimally invasive treatment methods.RFA principle is under ultrasound or CT guided percutaneous into the tumor,in this case metal tip will be issued high-frequency radio waves and cause tissue cell ion shock and friction heat.Tumor tissue compared with normal tissue to heat tolerance is poor.RF metal tip portion temperature can reach 70-120?, while high temperature can lead to cancer cell degeneration, coagulation necrosis and even charring.High temperature also enables tumor tissue intravascular coagulation.Necrotic tissue similar to a guard ring which not only can block the blood supply to cancer cells but also may prevent cancer metastasis with the blood. Liver cancer blood flow is mainly hepatic artery and portal vein, while 90% is arterial blood with a high oxygen content. Rapid growth of tumor tissue which internal containing many sinus and a lot of new capillaries.New blood capillaries compared to normal vessels lack of physiological reflex,thus resulting in poor stability of tumor tissue after heating.After the internal temperature increased tumor blood flow becomes slow and then later thrombosis resulting in blood flow is not smooth and reduced blood flow.Therefore, after radiofrequency ablation of tumor will occurs necrosis.RFA as a new treatment method has unique advantages especially in terms of prolong survival time in patients and control tumor progression plays an importantrole. Radiofrequency ablation in the treatment of liver cancer patients regardless of whether surgery can play a positive therapeutic effect. After 20 years of rapid development, RFA has played an extensive role in the clinical treatment ofmalignant process. Radiofrequency ablation is the second conventional surgery, ultra selective hepatic arterial chemoembolization is known as the third largest and efficient method to treat liver cancer.Radiofrequency ablation treatments include ultrasound?CT or MRI-guided percutaneous radiofrequency ablation, laparoscopic radiofrequency ablation and conventional surgery intraoperative radiofrequency ablation.Under the ultrasoundguided percutaneous transhepatic radiofrequency ablation therapy is a treatment clinic most commonly used, easy to operate, accurate positioning, intraoperative real-time observation, non-radioactive, less equipment and low cost. ObjectiveTo evaluate the efficiency and risk factors for effects after percutaneous radio- frequency ablation(RFA) for hepatic malignant tumors under the guidance of sonography. MethodsThe clinical data and the follow-up radiographic images of the patients with hepatic malignant tumors treated by percutaneous RFA were reviewed between March 2012 and March 2014 and the incomplete ablation rate, recurrance rate and tumor progression rate were calculated, and the factors affecting the incomplete ablation rate, recurrence rate and progression rate were analyzed. These factors include: age, sex, cirrhosis, whether combined hepatitis B, lesion location, tumor size, number of lesions, and whether the line before and after surgery CEUS.Factors that may affect the efficacy of RFA assignment, using SPSS17.0 statistical software for data processing, analysis of factors affecting the efficacy of using the chi-square test.Applications Sequoia512?GE Voluson730 and Mindray DC-8 ultrasound as a guidance system for intraoperative localization lesions, and ablation monitoring. Radiofrequency ablation system uses: RITA RFA system, Cool-Tip radiofrequency device, VIVI radiofrequency ablation system.Routine preoperative preparation, anesthesia before detailed ultrasound or contrast Reading CECT / CEMR sheet, a clear case of liver lesions.Comprehensive lesion location, size, select the appropriate radio frequency needle, needle cloth develop scientific programs.With reference to the size of the tumor and ablation instrument indications for tumor ablation.For HCC large diameter, next to the last point repeatedly ablation therapy and ablation of tumor edge than 0.5cm scope.Use multiple overlapping ablation this way as much as possible to ensure the effective range of the ablation and to reduce air leakage phenomenon.After the treatment is completed and prior to ablation foci within ultrasound prompted no significant blood flow at this time remove the needle radiofrequency ablation needle track line as much as possible to prevent postoperative bleeding and needle along the needle tract tumor metastasis. Results412 lesions were ablated in the total of 392 RFA procedures for 360 patients under the guidance of sonography with percutaneous method. The average size of the tumor was(2.51±1.10)cm. During at least 3 months follow up, complete and incomplete ablation rate was 86.11%(310/360)and recurrance rate and progression rate of tumor was7.78%(28/360)and6.1%(22/360). The location(close to vessels) of the lesions, size(?3cm) and numbers(?3cm) reduced the complete ablation rate(?2=4.431, 10.889, 8.000; p<0.05). The numbers(?3cm) of lesions affected the recurrence rate and progression rate of lesions as only risk factor(?2=29.032, 22.092, p<0.05). ConclusionUltrasound-guided percutaneous radiofrequency ablation(RFA) for the treatment of liver cancer safe, efficient approach. radiofrequency ablation of small hepatocellular carcinoma clinical efficacy ?low rate of recurrence and trauma healing wall after treatment. RFA can effectively control local progression of hepatic maglinant tumors.The tumor's size, number and location close to velssels could effect complete ablation rate,the number of tumors could effect the recurrence and porgression rate.