Summary： This study aimed to examine the optimal conditions of laser-induced interstitial ther- motherapy （LITT） via a single-needle delivery system, and the ablation-related pathological and ultra- sonic changes. ...Summary： This study aimed to examine the optimal conditions of laser-induced interstitial ther- motherapy （LITT） via a single-needle delivery system, and the ablation-related pathological and ultra- sonic changes. Ultrasound （US）-guided LITT （EchoLaser system） was performed at the output power of 2--4 Wattage （W） for 1-10 min in ex vivo bovine liver. Based on the results of the ex vivo study, the output power of 3 and 4 W with different durations was applied to in vivo rabbit livers （n=24）, and VX2 tumors implanted in the hind limbs of rabbits （n=24）. The ablation area was histologically determined by hematoxylin-eosin （HE） staining. Traditional US and contrast enhanced ultrasound （CEUS） were used to evaluate the treatment outcomes. The results showed： （1） In the bovine liver, ablation disruption was grossly seen, including a strip-like ablation crater, a carbonization zone anteriorly along the fiber tip, and a surrounding gray-white coagulation zone. The coagulation area, 1.2 cm in length and 1.0 cm in width, was formed in the bovine liver subjected to the ablation at 3 W for 5 min and 4 W for 4 rain, and it extended slightly with the ablation time. （2） In the rabbit liver, after LITT at 3 W for 3 min and more, the coagulation area with length greater than or equal to 1.2 cm, and width greater than or equal to 1.0 cm, was found. Similar coagulation area was seen in the implanted VX2 carcinoma at 3 W for 5 min. （3） Gross examination of the liver and carcinoma showed three distinct regions： ablation cra- ter/carbonization, coagulation and congestion distributed from the center outwards. （4） Microscopy re- vealed four zones after LITT, including ablation crater/carbonization, coagulation, edema and conges- tion from the center outwards. A large area with coagulative necrosis was observed around a vessel in the peripheral area with edema and hyperemia. （5） The size of coagulation was consistent well to the CEUS findings. It was concluded that EchoLaser system at low power can produce a coagulation area larger than 1.0 cm×1.0 cm during a short time period. The real-time US imaging can be used to effec- tively guide and assess the treatment.展开更多
The influence of heat source by laser irradiating on tissue temperature was simulated with the Ansys program, and the distribution of tissue temperature under the heat source was shown. Compared with others, the simul...The influence of heat source by laser irradiating on tissue temperature was simulated with the Ansys program, and the distribution of tissue temperature under the heat source was shown. Compared with others, the simulation method with aasys program is more intuitionistic and can offer very good reference for Laser-induced iaterstitial thermotherapy.展开更多
基金supported by grants from the National Natural Science Foundation of China(No.81000616)the Natural Science Foundation of Hubei Province,China(No.2009cdb264 and No.2012ffb02526)
文摘Summary： This study aimed to examine the optimal conditions of laser-induced interstitial ther- motherapy （LITT） via a single-needle delivery system, and the ablation-related pathological and ultra- sonic changes. Ultrasound （US）-guided LITT （EchoLaser system） was performed at the output power of 2--4 Wattage （W） for 1-10 min in ex vivo bovine liver. Based on the results of the ex vivo study, the output power of 3 and 4 W with different durations was applied to in vivo rabbit livers （n=24）, and VX2 tumors implanted in the hind limbs of rabbits （n=24）. The ablation area was histologically determined by hematoxylin-eosin （HE） staining. Traditional US and contrast enhanced ultrasound （CEUS） were used to evaluate the treatment outcomes. The results showed： （1） In the bovine liver, ablation disruption was grossly seen, including a strip-like ablation crater, a carbonization zone anteriorly along the fiber tip, and a surrounding gray-white coagulation zone. The coagulation area, 1.2 cm in length and 1.0 cm in width, was formed in the bovine liver subjected to the ablation at 3 W for 5 min and 4 W for 4 rain, and it extended slightly with the ablation time. （2） In the rabbit liver, after LITT at 3 W for 3 min and more, the coagulation area with length greater than or equal to 1.2 cm, and width greater than or equal to 1.0 cm, was found. Similar coagulation area was seen in the implanted VX2 carcinoma at 3 W for 5 min. （3） Gross examination of the liver and carcinoma showed three distinct regions： ablation cra- ter/carbonization, coagulation and congestion distributed from the center outwards. （4） Microscopy re- vealed four zones after LITT, including ablation crater/carbonization, coagulation, edema and conges- tion from the center outwards. A large area with coagulative necrosis was observed around a vessel in the peripheral area with edema and hyperemia. （5） The size of coagulation was consistent well to the CEUS findings. It was concluded that EchoLaser system at low power can produce a coagulation area larger than 1.0 cm×1.0 cm during a short time period. The real-time US imaging can be used to effec- tively guide and assess the treatment.
文摘The influence of heat source by laser irradiating on tissue temperature was simulated with the Ansys program, and the distribution of tissue temperature under the heat source was shown. Compared with others, the simulation method with aasys program is more intuitionistic and can offer very good reference for Laser-induced iaterstitial thermotherapy.
