Objective: To completely coagulate deep tumor and protect normal tissue by using microwave electrode is vivo and in vitro animal experimental study, under US-guided percutaneous microwave coagulation.
Method: The Ultrasound Microwave Therapy-I (UMT-I) equipment was utilized at 2450 MHz in frequency.
Results: Microwave coagulation could produce a stable necrosis area of 2cm in diameter with irradiation at 60-80W for 60-180 seconds, and the corresponding temperature at its surrounding area was 61.95 +/- 5.81 degrees C. Microwave induced coagulation of tumor correlated well with the sonographic changes. The shape of coagulated area was elliptic when 27 mm or 9 mm of the inner conductor of electrode was exposed, and the temperature of the shaft of the electrode raised smaller and slowly based on our animal experimental study, 15 nodules of 12 patients with liver cancer were microwave-coagulated under US-guide. The temperature of tumor surrounding area raised to 54-69.5 degrees C during operation. After treatment, all lesions had smaller size, hypoechogenicity and disappearance of blood flow. AFP titer dropped in 7 patients and normalized in 4.
Conclusion: US-guided microwave for the treatment of liver cancer is effective in coagulating deep tumor and protecting normal tissue.