Feasibility Study Of Ultrasound-guided Percutaneous Microwave Ablation On Treatment Of Lymphatic Metastatic Carcinoma In Cervical Part

Purposes: (1) To observe morphologic changes after the ablations by using an implanted antenna that could be internally cooled with a working frequency on 2450MHz microwave in vitro porcine tissue. (2) To observe pathologic changes and ranges after ablation of ultrasound-guided percutaneous microwave on lymphatic in vivo porcine. (3) To observe the microwave ablation's pathologic changes and ranges on lymph node of cervical part in patients with hypopharyngeal carcinoma. Then the feasibility of ultrasound-guided percutaneous microwave ablation on lymphatic in cervical part is studied.Materials and Methods: (1) Tissues is separated according to magnitude of output energy and action time. 2450MHz rigid implanted internally cooled microwave antennae are directly inserted into porcine liver tissues during ablation experiments, and temperature curves are simultaneously recorded at every selected time spots by iron-constantan couple temperature-measuring system. (2) Antennae of 2450MHz rigid implanted internally cooled microwave are inserted into lymph nodes in vivo porcine under ultrasound-guided percutaneous. 12 experiments are done which are used continuous wave irradiation pattern. 1 week later, animals are executed euthanasia. Tissues from neck part of porcine are dissected to observe the pathologic change. (3) 2450MHz rigid implanted internally cooled microwave antennae are inserted into lymph nodes of cervical part in patients with hypopharyngeal carcinoma. The pathologic changes are observed under transmission electron microscope and light microscope after ablation.Results: (1) The circumscription of pathologic changes caused by 2450MHz microwave ablation lesions is all elliptical and radial symmetry about the antenna, but the distribution of z axis was asymmetrical. The temperatures of spots in direction of z < 0 are higher than the ones of corresponding spots in direction of z > 0. The coagulation areas of 54℃are enlarged by increasing power in general. (2) Gross manifestations of ablation lesions after ablation with ultrasound-guided percutaneous in vivo porcine are corresponding with the pathological exhibition。The ablation shape can be controlled with changing the times and power magnitudes. (3) The results that 2450MHz rigid implanted internally cooled microwave antennae were inserted into lymph nodes in patients with hypopharyngeal carcinoma. With ultrasound-guided percutaneous and directly insert are effect and safe. The apoptosis could be observed under transmission electron microscope.Conclusions: The ablation circumscriptions in porcine tissues and lymphatic tissues in vivo porcine with ultrasound-guided percutaneous and lymphatic of cervical part in patients with hypopharyngeal carcinoma.is steady. The circumscription can be controlled by changing the power of ablation through real time monitoring with ultrasound according the size of the lymphatic. Therefore, this technique will demonstrate potentially applicable advantages and potential in clinical ablation treatments of recrudescent cervical metastatic cancer.