bjectiveTo evaluate the efficacy and limits of high intensity focused ultrasound (HIFU) in tumor treatment. MethodsThe references about the application of HIFU in tumor treatment in recent years were reviewed.ResultsHIFU caused localized hyperthermia at predictable depth in a few seconds to make the tumor tissue coagulative necrosis without injuring surrounding tissue. HIFU treatment had the advantages of low morbidity, noninvasiveness, avoidance of systemic side effects, and repeatitiveness. However, the utilization of HIFU sometimes could be limited by some factors such as imaging technique, organ movement, incomplete tissue destruction, etc.ConclusionHIFU is a promising noninvasive therapy for tumor treatment, though there are lots of problems to be further studied.
ObjectiveTo explore the effectiveness and safety of high intensity focused ultrasound (HIFU) in the treatment of pancreatic cancer, so as to provide references for its clinical application. MethodsPubMed, EMbase, The Cochrane Library (Issue 11, 2013), CBM, CNKI, VIP and WanFang Data were systematically searched up to November 2013 for randomized clinical trials (RCTs) and clinical controlled trials (CCTs) about HIFU in the treatment of pancreatic cancer. According to inclusion and exclusion criteria, two reviewers independently screened literature, extracted data, and assessed methodological quality of included studies. Then meta-analysis was performed using RevMan 5.0. ResultsA total of 23 studies (19 RCTs and 4 CCTs) were included, of which 14 studies reported safety. The results of meta-analysis showed that:survival rates at the 6th month and the 12th month, overall efficacy and clinical benefit rate in the HIFU plus radiation and chemotherapy group were significantly higher than those in groups treated with three dimensional conformal radiation therapy (3D-CRT) (P < 0.05), gemcitabine (GEM) (P < 0.05), GEM plus cisplatin (DDP) (P < 0.05), and GEM plus 5-fluorouracil (5-FU) (P < 0.05). The adverse effects (mainly including skin damage and fever) in the HIFU plus radiation and chemotherapy group was similar to those in the control group with no significant difference (P > 0.05). ConclusionCurrent evidence suggests that HIFU plus radiation and chemotherapy for pancreatic cancer is superior to other therapies with less adverse reaction. However, the poor quality of the included studies reduces the reliability of outcome to some extent. Thus, it is necessary to regulate and unify the criteria of diagnosis and outcome measures in the treatment of pancreatic cancer and improve the quality of study design and implementation in clinical studies, so as to provide high quality evidence for its clinical application.
The temperature during the brain tumor therapy using high-intensity focused ultrasound (HIFU) should be controlled strictly. This research aimed at realizing uniform temperature distribution in the focal region by adjusting driving signals of phased array transducer. The three-dimensional simulation model imitating craniotomy HIFU brain tumor treatment was established based on an 82-element transducer and the computed tomography (CT) data of a volunteer's head was used to calculate and modulate the temperature distributions using the finite difference in time domain (FDTD) method. Two signals which focus at two preset targets with a certain distance were superimposed to emit each transducer element. Then the temperature distribution was modulated by changing the triggering time delay and amplitudes of the two signals. The results showed that when the distance between the two targets was within a certain range, a focal region with uniform temperature distribution could be created. And also the volume of focal region formed by one irradiation could be adjusted. The simulation results would provide theoretical method and reference for HIFU applying in clinical brain tumor treatment safely and effectively.
A miniaturized, low-cost high-intensity focused ultrasound device is developed for the problems of cross-contamination and uneven sample fragmentation in conventional ultrasound devices. This device generates ultrasonic waves through a concave spherical self-focusing piezoelectric ceramic piece, and creates a cavitation effect in the focusing area to achieve sample fragmentation. The feasibility of the device is demonstrated by physical simulation, then a driving circuit with adjustable power is designed and manufactured to generate 0 ~ 22.4 W acoustic power, and finally paraffin-embedded sample dewaxing experiments are performed to verify the validation of the device. The experimental results show that the dewaxing efficiency and safety of the high-intensity focused ultrasound device is significantly better than those of traditional chemical methods, and this device is comparable with commercial ultrasonic instruments. In summary, the high-intensity focused ultrasound device is expected to be applied in automated nucleic acid extraction and purification equipment and has a broad application prospect in the field of sample pre-processing.
【Abstract】ObjectiveTo investigate the effect of high intensity focused ultrasound (HIFU) on the immunity of patients with advanced primary liver cancer (PLC). MethodsForty cases of PLC admitted to our institution from Mar. 2003 to Dec. 2003 were included in this study. Patients were divided into 2 groups and received either HIFU or radiofrequency ablation (RFA) treatment randomly. CD3, CD4, CD8, CD4/CD8, NK, IL-2, TNF were chosen to assess the immune status before and after treatment. The results were compared statistically. ResultsThe survival rate after HIFU was 80.0%, 61.1%, 42.9%, 33.3% at 3 months, 6 months, 9 months and 1 year respectively, which was similar to that after RFA treatment. The changes of immunity parameters of CD3, CD4, CD8, CD4/CD8, NK, IL-2 and TNF were not significant after HIFU treatment. In addition, the differences of those parameters between HIFU group and RFA group were insignificant. ConclusionThere are no detrimental effects on immunity in the early period after HIFU treatment.
ObjectiveTo explore the application value of high intensity focused ultrasound (HIFU) in the treatment of advanced pancreatic cancer.MethodThe domestic and foreign literatures about studies of HIFU treating advanced pancreatic cancer in recent years were retrieved and summarized.ResultsHIFU could prolong the survival time, control pain, and enhance the body’s immune function in patients with advanced pancreatic cancer. There were no obvious serious complications during the treatment process. The combined treatment with radiotherapy, chemotherapy, and traditional Chinese medicine could obviously prolong the survival time and improve the quality of life for the patients with advanced pancreatic cancer.ConclusionsHIFU is an important component in the comprehensive treatment of advanced pancreatic cancer. However, because there is no uniform standard for the dosage of HIFU treatment, the sample size of many related studies is small, so the research results have certain limitations, so more studies are needed to improve their understanding of advanced pancreatic cancer in order to better serve clinical workin future.
ObjectiveTo evaluate the effects of high intensity focused ultrasound (HIFU) on hepatic cancer cells spreading in blood.Methods AFP mRNA in peripheral blood of 19 patients with hepatocellular carcinoma was detected before and after HIFU therapy by RTPCR.Results①Before HIFU therapy, 11 of 19 cases were AFP mRNA positive (57.9%), while the control group were all negative. AFP mRNA was correlated with some clinical parameters such as serum AFP level, tumor size, portal vein embolism and extrahepatic metastasis (P＜0.05). ②In 8 cases with preoperative AFP mRNA negative, only 2 cases became AFP mRNA positive immediately after therapy, and one of the 2 cases became negative again after 72 hours. One week after HIFU therapy, the AFP mRNA positive rate (31.6%) was much lower than the preoperative positive rate (57.9%), but there was no statistical significance (Pgt;0.05). ③After one week of HIFU therapy, the AFP mRNA positive rate of the group with tumor size less than 8 cm was much lower than that of tumor size larger than 8 cm (P＜0.05). ConclusionHIFU may reduce the spreading of hepatocellular carcinoma cells in blood. It is effective for patients with tumor size less than 8 cm.
Numerical simulation is one of the most significant methods to predict the temperature distribution in high-intensity focused ultrasound (HIFU) therapy. In this study, the adopted numerical simulation was used based on a transcranial ultrasound therapy model taking a human skull as a reference. The approximation of the Westervelt formula and the Pennes bio-heat conduction equation were applied to the simulation of the transcranial temperature distribution. According to the temperature distribution and the Time Reversal theory, the position of the treatable focal region was corrected and the hot spot existing in the skull was eliminated. Furthermore, the influence of the exposure time, input power and the distance between transducer and skull on the temperature distribution was analyzed. The results showed that the position of the focal region could be corrected and the hot spot was eliminated using the Time Reversal theory without affecting the focus. The focal region above 60℃ could be formed at the superficial tissue located from the skull of 20 mm using the hot spot elimination method and the volume of the focal region increases with the exposure time and the input power in a nonlinear form. When the same volume of the focal region was obtained, the more power was inputted, the less the exposure time was needed. Moreover, the volume of the focal region was influenced by the distance between the transducer and the skull.