Objective To summarize the progress of the application of ultrasound-guided thermal ablation for treatment of papillary thyroid microcarcinoma (PTMC). Methods The relevant literatures of thyroid nodules treated by ultrasound-guided thermal ablation were reviewed by adopting the methods of literature review. Results In conditions of grasping the therapeutic indication strictly and evaluating preoperative various aspects sufficiently, it reveals a certain feasibility and validity applying ultrasound-guided thermal ablation in the treatment of PTMC classified in the low-risk group. Conclutions Possessing the advantages of minimal invasive techniques, low-risks, beauty and rapidness, ultrasound-guided thermal ablation might be recommended as an alternative to a low-risk PTMC patient who is at high risk in general anaesthesia operation or intolerant to open operation.
ObjectiveTo investigate the research progress of residual nodules after thermal ablation for benign thyroid nodules.MethodsThe domestic and foreign guidelines and consensus on the treatment of benign thyroid nodules were collected, and the indications for thermal ablation were summarized. The causes of residual nodules after ablation were analyzed, the characteristics of residual nodules were evaluated through multiple approaches, and the follow-up treatment measures were summarized.ResultsThe indications of thermal ablation of benign thyroid nodules were different at home and abroad. The causes of residual nodules included slow absorption after ablation and incomplete ablation. Among the evaluation methods of residual nodules, the nodules volume reduction rate was the evaluation standard of short-term efficacy, contrast-enhanced ultrasound was the best method, color Doppler blood color distributionwas the most commonly used method, elastic imaging was a valuable method, and puncture pathology biopsy was an important standard. Reablation and surgical resection were the follow-up treatments for residual nodules.ConclusionsAs a new technique, thermal ablation of benign thyroid nodules has some advantages, but it is flooding at present. In the future, it is necessary to standardize indications, improve the efficiency of first ablation, attach importance to pathological complete ablation, and reasonably evaluate the treatment of residual nodules, so that thermal ablation of benign thyroid nodules could reflect rationality, safety, and efficiency, and give full play to its advantages, so as to serve patients better and have better application prospects.
The temperature dependence of relative permittivity and conductivity of ex-vivo pig liver, lung and heart at 2 450 MHz was studied. The relative permittivity and conductivity of three kinds of biological tissues were measured by the open-end coaxial line method. The dielectric model was fitted according to the principle of least square method. The results showed that the relative permittivity and conductivity of pig liver, pig lung and pig heart decreased with the increase of tissue temperature from 20 to 80 ℃. The relative permittivity and conductivity models of pig liver, pig lung and pig heart were established to reflect the law of dielectric properties of biological tissue changing with temperature and provide a reference for the parameters setting of thermal ablation temperature field.
ObjectiveTo explore the factors that affect the accuracy of percutaneous thermal ablation of lung metastases and coping strategies.MethodsWe retrospectively analyzed the clinical data of 31 patients who met the conditions for thermal ablation of lung metastases in Ninth People’s Hospital affiliated to Shanghai Jiao Tong University School of Medicine between October 2019 and December 2020. There were 19 males and 12 females with a mean age of 40-81 (62.8±10.3) years. A total of 33 metastases tumors were thermally ablated, 12 were radiofrequency ablation and 19 were microwave ablation.ResultsOf the 33 metastatic tumors, 5 targets showed significant puncture deviation, 4 of them completed the ablation after adjustment and 1 failed. The result of the univariate logistic regression showed the distance within the lung parenchyma (P=0.043) and the maximum diameter of the tumor (P=0.025) were independent risk factors for the accuracy of percutaneous thermal ablation. In terms of correlation, there was a positive correlation between the accuracy of percutaneous thermal ablation and the distance within the lung parenchyma (P=0.033), and a negative correlation between the maximum diameter of metastases tumor (P=0.004) and hemoptysis (P=0.015). Complete ablation rate was 87.8% (29/33).ConclusionWhen we perform CT-guided percutaneous thermal ablation of lung metastases, we must fully prepare the deviation plan for the small diameter tumor, the long travel distance in the lung parenchyma, and hemoptysis during puncture. Complete ablation can be achieved by fully identifying the anatomical features of the tumor and its surrounding structures, shortening the travel distance in the lung parenchyma and increasing the ablation range.
Lobectomy and systematic nodules resection has been the standard surgical procedure for non-small cell lung cancer (NSCLC). However, increased small-size lung cancer has been identified with the widespread implementation of low-dose computed tomography (LDCT) screening, and it is controversial whether it is proper to choose lobar resection for the pulmonary nodules. Numerous retrospective researches and randomized clinical trials, such as JCOG0201, JCOG0804/WJOG4507L, JCOG0802 and CALGB/Alliance 140503, revealed that the sublobar resection was safe and effective for NSCLC with maximum tumor diameter≤2 cm and with consolidation tumor ratio (CTR)≤0.25, and that segmentectomy was superior to lobectomy with significant differences in 5-year overall survival rate and respiratory function for patients with small-size (≤2 cm, CTR>0.5) NSCLC and should be the standard surgical procedure. It is the principle for multiple primary lung cancer that priority should be given to primary lesions with secondary lesions considered, and it is feasible to handle the multiple lung nodules based on the patients' individual characteristics.
Although surgical resection remains to be the best treatment strategy for stageⅠnon-small cell lung cancer (NSCLC), percutaneous thermal ablation offers an important option for patients who are unable to undergo surgical resection. Currently, there are three main thermal ablation methods used in the treatment of lung cancer, including radiofrequency ablation (RFA), microwave ablation (MWA) and argon-helium cryoablation (AHC). With the improvement of technique and the accumulation of experience in the treatment of lung cancer, some limitations are disclosed in the initial application of RFA, such as heat sink effect, skin burns and rapid carbonization. These shortcomings have been overcome in the development of MWA and AHC. The feasibility and safety of thermal ablation for the treatment of lung cancer has been demonstrated and its efficacy has been significantly improved (especially for the tumour diameter≤3 cm). This article will focus on the application and recent research developments of these ablation techniques in the treatment of lung cancer.