Experimental Study On High Intensity Focused Ultrasound Irradiation In Porcine Pancreas And Clinical Application Study In Pancreatic Cancer

Objective: To explore the theoretical evidences and evaluate its feasibility and safety of HIFU's clinical application in pancreatic cancer by observing biochemistry and pathological change in swines pancreas damaged by HIFU.Methods: 6 mongrel pigs were randomly divided into two groups as A and B.After successful intravenous anesthesia by 3% butaylone, FEP-BY02 type HIFU was applied to irradiate in vivo porcine pancreas in group A and B. range 3 cm×3cm,t2(intermission time)∶t1 (unit transmit time)≈150ms:150ms, treatment times at each spot ,60 ,focus sound power density ,800W/cm2,step distance,4mm,row pitch ,4mm,layer distance, 5mm.The porcines were killed at the instant time ( group A) and on the fifth day after the operation. (group B). TTC staining and Hematoxylin and eosin (HE) staining was used to observe the pathological changes of injured pancreases. The level of blood and urine amylase and so on were examined regularly before and after HIFU. All 37 patients were irradiated by FEP-BY02 HIFU system in conscious status. step distance and row pitch , 4mm,layer distance, 5mm .input power, 400-600W ,t2(intermission time)∶t1 (unit transmit time)≈120ms:150ms,treatment times at each spot ,50-60,at least one hour every treat ,cover tumer at least one time. In order to evaluate the safety ,the change of blood and urine amylase,Liver and kidney function and so on were monitored befoe and after treat after a week. The body temperature,pulse,blood pressure,pain or not,skin burn,perforation of intestine and stomach also were inspect. Observe CA19-9,NRS,the change of pain-killer,weight,the appearance of CT and ultrasound,survival time so as to assess efficacy.Results: During the operation the state of swines were smooth and the survivability was fine. There were no serious complications HIFU-induced such as skin burns ,acute pancreatitis ,damage to the stomach or intestine were observed in group B and A. Coagulation necrosis regions were found in all HIFU irradiation region in specimens of group A and B. The level of blood and urine amylase were steady in five days in group B. After HIFU,the CBR(cilnical benefit response) of all 37 patients are 72.9%(27/37); 83.7%(31/37)patients ultrasound echo upgraded ;the tumer size change of CT: 29.7 %(11/37)obviously shrink, 49.2 % ( 29/59 ) no change, 22% ( 8/37 ) swelling.The concentration of CA19-9 decreased from 69.6±15.4U/mlto 18.5±6.3U/ml after HIFU. There were also no serious complications HIFU-induced such as skin burns ,acute pancreatitis ,damage to the stomach or intestine in 37 patients.Conclusion: The use of US-guided HIFU in the ablation of vivo swine is safe , effective and feasible.It can result in coagulation necrosis in pancreatic tissue . HIFU offered a effective and safe local method for the treatment of pancreatic cancer.