Research Of The Safety And Validity Treatment Of Rabbit Liver Cancer With Steep Pulse

Steep pulse(SP) is a new tissue ablation technique in which certain short duration electrical fields are used to permanently permeabilize the cell membrane, presumably through the formation of nanoscale defects in the membrane, which causes cell death only the targeted tissue without destroying critical structures.Because it could ablate tissue non termally, controllably, quickly, and safely; it seems promising to become an additional device in tumor combined therapy. SP has gotten considerable attention. In this study , the rabbit VX2 liver cancer model were treated by steep pulse , and then the safety and efficiency were detetmined.The main results are as follows:PART 1 RESEARCH OF THE DOSE-EFFECT RELATIONSHIP OF STEEP PULSE IN THE TREATMENT OF RABBIT LIVER CANCERObjective To investigate the optimal dosage of steep pulse in the treatment of rabbit VX2 liver cancer.Material and methods The VX2 liver cancer models were established in 30 New Zealand rabbits, and then rabbits were randomly divided into five group: 700V,800V,900V,1000V and control group.The experimental group received SP therapy; the control group did not receive any therapy. After 3 days, rabbits were sacrificed to measure the volume of the necrosis tissue and observe the pathological changes of target tissue. Results Coagulation necrosis occurred in tumor tissues exposed to electrical pulse field, with a dose-dependent manner. The necrosis area increased gradually with the increasing of the electric-field intensity. When the tumor tissue was exposed to electrical pulsed fields of 900 V, the tumor tissue appeared the necrosis obviously.And there was not clear to find any activity cancer cell. The 900V may be considered as the optimal dosage for the treatment of rabbit liver VX2 tumor.Observe the the pathological changes of target tissue:the disorder cells of control group were heteromorphism . There was clear to find the cells with karyokinesis. The tissues treated by SP were coagulation necrosis and the necrosis outline coincided with the simulation model of steep pulse field distribution .Conclusion There was a dose-dependence manner when ablating cancer with SP. The 900V may be considered as the optimal dosage for the treatment of rabbit liver VX2 cancer.The electric fields distribution on the rabbits liver cancer in vivo was similar with the the simulation model of steep pulse field distribution .PART 2 RESEARCH OF THE SAFETY AND VALIDITY OF STEEP PULSE IN THE TREATMENT OF RABBIT LIVER CANCERObjective To investigate the safety and validity of steep pulse in the treatment of rabbit liver cancer.Material and methods 20 New Zealand rabbits were established the VX2 liver cancer model .The rabbits were randomly divided into two groups: the experimental group received SP therapy; the control group did not receive any therapy.The liver function, renal function and hemogram were examined at predetermined times. The curative effect and the life span of the rabbits were followed.Results Liver function of the experiment group changed apparently in 24 hours(P<0.05) and restored gradually to the normal level in the 4th day(P>0.05).There was no significant difference between before and after SP treatment in renal function and hemogram of the experiment group (P>0.05). Liver function ,renal function and hemogram of the control group were no significant difference between before and after blank treatment (P>0.05). The survival durations were 67.2 days and 34.7 days in experimental and control groups, respectively. There was a significant difference in survival curve between the experimental group and control group( P<0.05). It seemed that the survival period of tumor-bearing rabbit maybe prolonged.Conclusion These results suggested that SP can treated the rabbit VX2 liver cancer safely and validly. Steep pulse seems promising to become an additional device in tumor combined therapy.