Twelve patients were treated with HIFU from October sellekchem 2008 to May 2010. Table 1 summarizes the patients’ data. The 12 patients were determined to be eligible for HIFU treatment by using the following criteria: they had a diagnosis of pancreatic cancer as confirmed by the pathologic findings or by the clinical and imaging findings typical of pancreatic cancer, the tumor was unresectable based on the guidelines of the 6th edition of the American Joint Committee on Cancer (AJCC), the lesion was mainly located in the pancreatic head or body and they had a Karnofsky performance status scale rating of at least 70%.

Table 1 Summary of Patients Treated with High Intensity Focused Ultrasound The following inclusion criteria were used to examine the effect of CCHT: 1) the patients underwent at least three sessions of concurrent treatments, which were defined as HIFU within 24 hours of a gemcitabine injection, 2) initiation of the first CCHT was done within three months of the diagnosis to meet the requirements that concurrent treatment should be the main treatment and 3) there was no history of radiation or cyberknife treatment before and after CCHT. Three of the 12 patients satisfied these criteria and they were categorized into the “CCHT group.” The other nine patients were categorized into the “non-CCHT group.” The High Intensity Focused Ultrasound Device A FEP-BY? HIFU unit (Yuande Biomedical Engineering Limited Corporation, Beijing, China) was used throughout this study (14). The HIFU treatment was performed using an upper HIFU transducer enveloped in a degassed water bladder with the patient lying supine on the treatment table.

The targeted pancreatic tumor was identified using a B-mode ultrasound imaging transducer (GE Logiq 5, Seongnam, Republic of Korea) before the HIFU treatment. The HIFU beam was insonated into the body and moved automatically from spot to spot in an overlapping manner to treat a volume of tissue. Local or general anesthesia was not needed in any of the patients. The patients were fasted for nine hours before the HIFU treatment. The treatment parameters were input target energy: 500-1000 J/spot, input acoustic intensity (spatial average-temporal average intensity, Isata): 1-2 kW/cm2, pulses/spot: 50-70, transit time of a unit pulse (t1): 150 ms and intermission time between pulses (t2): 150 ms, intermission time between spots: 5 sec (duty cycle: 50%, pulse repetition frequency: 3.

3 Hz, sonication duration: 15-21 sec). The acoustic power was adjusted with respect to the tumor depth and the subcutaneous tissue thickness, as measured by ultrasound AV-951 imaging, to achieve the required in situ energy dose (15). To avoid skin burns, a cold ultrasound coupling gel was applied frequently between the water bladder and skin during the procedure.