AIM:To evaluate the safety and clinical application of high-intensity focused ultrasound(HIFU)therapy for unresectable pancreatic cancer(PC).METHODS:Thirty PC patients(16 cases in stage III and 14 cases in stage IV)with visualized pancreatic tumors were admitted for HIFU therapy as an optional local therapy in addition to systemic chemotherapy or chemoradiotherapy.Informed consent was obtained.This study began at the end of 2008 and was approved by the ethics committee of our hospital[Institutional Review Board(IRB):890].The HIFU device used was the FEP-BY02(Yuande Bio-Medical Engineering,Beijing,China).RESULTS:The mean tumor size after HIFU therapy changed to 30.9±1.7 mm from 31.7±1.7 mm at pre-therapy.There were no significant changes in tumor size,mean number of treatment sessions(2.7±0.1 mm),or mean total treatment time(2.4±0.1 h).The rate of symptom relief effect was 66.7%.The effectiveness of primary lesion treatment was as follows:complete response,0;partial response,4;stable disease,22;progressive disease,4.Treatment after HIFU therapy included 2 operations,24 chemotherapy treatments,and 4 best supportive care treatments.Adverse events occurred in 10%of cases,namely pseudocyst formation in 2 cases and mild pancreatitis development in 1.However,no severe adverse events occurred in this study.CONCLUSION:We suggest that HIFU therapy is safe and has the potential to be a new method of combination therapy for PC. AIM: To evaluate the safety and clinical application of high-intensity focused ultrasound (HIFU) therapy for unresectable pancreatic cancer (PC). METHODS: Thirty PC patients (16 cases in stage III and 14 cases in stage IV) with visualized pancreatic tumors were admitted for HIFU therapy as an optional local therapy in addition to systemic chemotherapy or chemoradiotherapy. Informed consent was obtained. This study began at the end of 2008 and was approved by the ethics committee of our hospital [Institutional Review Board (IRB): 890] The HIFU device used was the FEP-BY02 (Yuande Bio-Medical Engineering, Beijing, China) .RESULTS: The mean tumor size after HIFU therapy changed to 30.9 ± 1.7 mm from 31.7 ± 1.7 mm at pre-therapy. Where were no The significant changes in tumor size, mean number of treatment sessions (2.7 ± 0.1 mm), or mean total treatment time (2.4 ± 0.1 h). The rate of symptom relief effect was 66.7%. The effectiveness of primary lesion treatment was as follows: complete response, 0; partial response, 4; stabl e disease, 22; progressive disease, 4. Treatment after HIFU therapy included 2 operations, 24 chemotherapy treatments, and 4 best supportive care treatments. Adverse events occurred in 10% of cases, respectively, pseudocyst formation in 2 cases and mild pancreatitis development in 1 .However, no severe reverse events occurred in this study. CONCLUSION: We suggest that HIFU therapy is safe and has the potential to be a new method of combination therapy for PC.