High-intensity focused ultrasound combined with transarterial chemoembolization for unresectable hepatocellular carcinoma: long-term follow-up and clinical analysis

Safety of Sonazoid in Assisting High-Intensity Focused Ultrasound Ablation Therapy for Advanced Liver Malignant Lesions: A Single-Arm Clinical Study

OBJECTIVE

The aim of the study described here was to evaluate the safety of Sonazoid-assisted high-intensity focused ultrasound (HIFU) in the treatment of advanced malignant liver lesions.

METHODS

A single-arm study was designed to enroll participants who were diagnosed with advanced primary liver cancer or liver metastases and proposed to receive Sonazoid assistance during HIFU treatment. Serological examination was conducted within 1 wk, and side effects in each patient were monitored for 1 mo. To evaluate therapeutic efficacy, the contrast-enhanced magnetic resonance imaging was performed 1 mo after treatment, and short-term follow-up was conducted a year later.

RESULTS

A total of 17 participants (12 male, 5 female) with an average age of 58 y (range: 46-73 y) were enrolled, including 11 patients with hepatocellular carcinoma, 2 patients with hepatic metastasis and 4 patients with cholangiocarcinoma. The total volume of tumor mass was 111.82 (11.01-272.30) cm3. The average total ablation time for a patient was 2021 ± 1030 s, and the energy efficiency factor was 5979.7 (3108.0, 45634.5) J/cm3. Immediately after HIFU treatment, 1 patient (5.9%) achieved complete response (CR), 4 patients (23.5%) had a moderate response, 8 patients (47.1%) had partial reperfusion and 4 patients (23.5%) had stable disease (SD). The average ablation rate for all the tumors was 51.5 ± 26.7%. The level of glutamic-pyruvic transaminase (ALT) was mildly increased in 71.6% (12/17) of patients after HIFU therapy. Mean ALT values before and after treatment were 22 (14, 35) U/L and 36 (25, 41) U/L, respectively (Z = 1.947, p = 0.051). Mild or obvious edema in skin and subcutaneous soft tissues were observed in 76.5% of patients, but no serious side effects were found. Twelve months after treatment, the follow-up results revealed that 1 patient (5.8%) achieved a CR, 8 patients (47.1%) had SD and 8 patients (47.1%) had progressive disease. The estimated median time to progression was 11 mo after treatment, with a 95% confidence interval of 6, 11 for all involved patients.

CONCLUSION

Use of Sonazoid is safe and feasible for improving HIFU ablation efficiency during the treatment of advanced malignant liver lesions. The therapeutic efficacy of Sonazoid-assisted HIFU needs to be explored in additional controlled clinical investigations.

Controlled Hyperthermia With High-Intensity Focused Ultrasound and Ultrasound Contrast Agent Microbubbles in Porcine Liver

OBJECTIVE

The objective of this work was to study microbubble-enhanced temperature elevation with high-intensity focused ultrasound (HIFU) at different acoustic pressures and under image guidance. The microbubbles were administered with either local or vascular injections (that mimic systemic injections) in perfused and non-perfused ex vivo porcine liver under ultrasound image guidance.

METHODS

Porcine liver was insonified for 30 s with a single-element HIFU transducer (0.9 MHz, 0.413 ms, 82% duty cycle, focal pressures of 0.6-3.5 MPa). Contrast microbubbles were injected either locally or through the vasculature. A needle thermocouple at the focus measured temperature elevation. Diagnostic ultrasound (Philips iU22, C5-1 probe) guided placement of the thermocouple and delivery of microbubbles and monitored the procedure in real time.

RESULTS

At lower acoustic pressures (0.6 and 1.2 MPa) in non-perfused liver, inertial cavitation of the injected microbubbles led to greater temperatures at the focus compared with HIFU-only treatments. At higher pressures (2.4 and 3.5 MPa) native inertial cavitation in the tissue (without injecting microbubbles) resulted in temperature elevations similar to those after injecting microbubbles. The heated area was larger when using microbubbles at all pressures. In the presence of perfusion, only local injections provided a sufficiently high concentration of microbubbles necessary for significant temperature enhancement.

CONCLUSION

Local injections of microbubbles provide a higher concentration of microbubbles in a smaller area, avoiding acoustic shadowing, and can lead to higher temperature elevation at lower pressures and increase the size of the heated area at all pressures.

HIFU for the treatment of gastric cancer with liver metastases with unsuitable indications for hepatectomy and radiofrequency ablation: a prospective and propensity score-matched study

Background

The purpose of this study was to explore the efficacy and safety of high intensity focused ultrasound (HIFU) in gastric cancer with liver metastasis (GCLM) patients who were contraindicated for either hepatectomy or radiofrequency ablation (RFA).

Methods

This is a prospective, observational study on GCLM patients with 1–3 liver metastases. The primary gastric lesions were thoroughly resected and any case that exhibited extra-hepatic metastasis was excluded. A 1:2:2 propensity score-matching analysis was performed using a logistic regression model on the HIFU group, best supportive care (BSC) group, and palliative chemotherapy (PC) group. The primary endpoints include progression-free survival (PFS) and overall survival (OS).

Results

Forty patients were finally included, there were 8 cases in HIFU group, 16 cases in BSC group, and 16 cases in PC group. The median follow-up time for the entire cohort was 10 months. The median PFS was 16.5 months in HIFU group, 2 months in BSC group, and 5 months in PC group. The median OS was 27.5 months in the HIFU group, 7 months in the BSC group, and 11.5 months in the PC group. Additionally, no grade 3 or higher adverse events occurred in the HIFU group.

Conclusion

The results of this study showed that HIFU treatment could improve the long-term prognosis of GCLM patients without a significant increase in the occurrence of adverse events. Compared with PC and BSC, HIFU is the preferred treatment option when GCLM patients without extra-hepatic metastasis are unable to undergo either surgery or RFA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01307-y.

High-intensity focused ultrasound alone or combined with transcatheter arterial chemoembolization for the treatment of hepatocellular carcinoma with unsuitable indications for hepatectomy and radiofrequency ablation: a phase II clinical trial

OBJECTIVES

This study aims to evaluate the efficacy and safety of high-intensity focused ultrasound (HIFU) alone or combined with transcatheter arterial chemoembolization (TACE) for patients with hepatocellular carcinoma (HCC) but were contraindicated for hepatectomy and radiofrequency ablation (RFA).

METHODS

Patients between 20 and 80 years of age with 1-3 foci of HCC were selected. Included patients have had primary or recurrent liver lesions with no evidence of extra-hepatic metastasis prior to the study. Patients were treated with ultrasound-guided HIFU alone or HIFU combined with TACE (treated with TACE once within 4 weeks prior to receiving HIFU).

RESULTS

Thirty-seven patients were enrolled, for a total of 45 lesions. The 2-year local control (LC) rate was 73.0% and the median LC time was 22 months. The 2-year progression-free survival (PFS) was 29.7% and the median PFS time was 9 months. Finally, the 2-year overall survival (OS) was 70.3%, and the median OS time was 24 months. The most common adverse events (AEs) were elevated liver enzymes, followed by fatigue, and pain, no grade 4 AEs or death occurred. Multivariate analysis showed that age, Child-Pugh class, and the number of tumors were independent prognostic factors for PFS and that the AFP levels and the number of tumors were significantly correlated with the OS.

CONCLUSIONS

This study indicates that the HIFU/HIFU combined with TACE treatment is safe, and is capable of achieving both a good LC rate and a considerably good prognosis. The procedure should be considered for patients who were deemed unsuitable for other local treatments.

Systematic review of the role of high intensity focused ultrasound (HIFU) in treating malignant lesions of the hepatobiliary system

BACKGROUND

High Intensity Focused Ultrasound (HIFU) is an emerging non-invasive, targeted treatment of malignancy. The aim of this review was to assess the efficacy, safety and optimal technical parameters of HIFU to treat malignant lesions of the hepatobiliary system.

METHODS

A systematic search of the English literature was performed until March 2020, interrogating Pubmed, Embase and Cochrane Library databases. The following key-words were input in various combinations: 'HIFU', 'High intensity focussed ultrasound', 'Hepatobiliary', 'Liver', 'Cancer' and 'Carcinoma'. Extracted content included: Application type, Exposure parameters, Patient demographics, and Treatment outcomes.

RESULTS

Twenty-four articles reported on the clinical use of HIFU in 940 individuals to treat malignant liver lesions. Twenty-one studies detailed the use of HIFU to treat hepatocellular carcinoma only. Mean tumour size was 5.1 cm. Across all studies, HIFU resulted in complete tumour ablation in 55% of patients. Data on technical parameters and the procedural structure was very heterogeneous. Ten studies (n = 537 (57%) patients) described the use of HIFU alongside other modalities including TACE, RFA and PEI; 66% of which resulted in complete tumour ablation. Most common complications were skin burns (15%), local pain (5%) and fever (2%).

CONCLUSION

HIFU has demonstrated benefit as a treatment modality for malignant lesions of the hepatobiliary system. Combining HIFU with other ablative therapies, particularly TACE, increases the efficacy without increasing complications. Future human clinical studies are required to determine the optimal treatment parameters, better define outcomes and explore the risks and benefits of combination therapies.

High-Intensity Focused Ultrasound Ablation for Unresectable Primary and Metastatic Liver Cancer: Real-World Research in a Chinese Tertiary Center With 275 Cases

This retrospective analysis was conducted to evaluate the feasibility and safety of high-intensity focused ultrasound ablation for primary liver cancer and metastatic liver cancer. Patients with liver cancer who received high-intensity focused ultrasound were included in this analysis, including a primary liver cancer cohort (n=80) and a metastatic liver cancer cohort (n=195). The primary endpoint of our research was tumor response. The secondary endpoints included survival outcomes, visual analog scale pain scores, alpha-fetoprotein relief, and complications. Objective response rate and disease control rate were observed to be 71.8% and 81.2%, respectively, in patients with primary liver cancer and were 63.7% and 83.2% in cases with metastatic liver cancer. Alpha-fetoprotein levels and visual analogue scale levels significantly decreased after treatment compared with the baseline levels in patients with primary liver cancer (p<0.05). Median overall survival was estimated to be 13.0 and 12.0 months in the primary liver cancer and metastatic liver cancer cohorts. The 1-year survival rate was 70.69% and 48.00%, respectively. Multivariate regression analysis showed that visual analogue scale ≥ 5, longest diameter ≥ 5 cm, and portal vein invasion were the independent risk factors for poor survival in primary liver cancer. For patients with metastatic liver cancer, independent risk factors were identified as visual analogue scale ≥ 5, longest diameter ≥ 5 cm, existence of extrahepatic metastases, existence of portal vein invasion, and time to high-intensity focused ultrasound treatment from diagnosis < 3 months. Severe adverse events were rarely reported. In conclusion, high-intensity focused ultrasound might be an effective and safe option for patients with liver cancer regardless of primary and metastatic lesions.

Feasibility of High-Intensity Focused Ultrasound for Hepatocellular Carcinoma after Stereotactic Body Radiation Therapy: Initial Experience

The purpose of this initial clinical observation was to investigate the safety and effect of high-intensity focused ultrasound (HIFU) for patients with hepatocellular carcinoma (HCC) after stereotactic body radiation therapy (SBRT). Twenty patients who had been treated with SBRT, with 24 local residuals, received HIFU ablation. The changes of periphery blood cell count and serum biochemistry were observed before HIFU and 1 week after. Contrast-enhanced magnetic resonance imaging before HIFU and 2 weeks after was performed to assess the effect of HIFU. All patients received follow-up. The mean ± standard deviation follow-up time was 19.3 ± 18.0 mo. The median survival time and 1-y survival rate were 21 mo and 76.2%. Seventeen residual lesions (70.8%) received complete ablation and seven received partial ablation, with a mean ablation ratio of 75.8% ± 18.2%. No significant differences were found in periphery blood cell counts or serum biochemistry 1 week after HIFU compared with before HIFU. No severe adverse reactions related to HIFU were observed. Thus, we believe that HIFU can safely and effectively ablate residual HCC after SBRT, which may be a feasible option for patients with HCC who have local residuals after SBRT.

Phenotypic alterations in liver cancer cells induced by mechanochemical disruption

Hepatocellular carcinoma (HCC) is a highly fatal disease recognized as a growing global health crisis worldwide. Currently, no curative treatment is available for early-to-intermediate stage HCC, characterized by large and/or multifocal tumors. If left untreated, HCC rapidly progresses to a lethal stage due to favorable conditions for metastatic spread. Mechanochemical disruption of cellular structures can potentially induce phenotypic alterations in surviving tumor cells that prevent HCC progression. In this paper, HCC response to mechanical vibration via high-intensity focused ultrasound and a chemical disruptive agent (ethanol) was examined in vitro and in vivo. Our analysis revealed that mechanochemical disruption caused a significant overproduction of reactive oxygen species (ROS) in multiple HCC cell lines (HepG2, PLC/PRF/5, and Hep3B). This led to a decrease in cell viability and long-term proliferation due to increased expression and activity of death receptors TNFR1 and Fas. The cells that survived mechanochemical disruption had a reduced expression of cancer stem cell markers (CD133, CD90, CD49f) and a diminished colony-forming ability. Mechanochemical disruption also impeded HCC migration and their adhesion to vascular endothelium, two critical processes in hematogenous metastasis. The HCC transformation to a non-tumorigenic phenotype post mechanochemical disruption was confirmed by a lack of tumor spheroid formation in vitro and complete tumor regression in vivo. These results show that mechanochemical disruption inhibits uncontrolled proliferation and reduces tumorigenicity and aggressiveness of HCC cells through ROS overproduction and associated activation of TNF- and Fas-mediated cell death signaling. Our study identifies a novel curative therapeutic approach that can prevent the development of aggressive HCC phenotypes.

Ablation plus Transarterial Embolic Therapy for Hepatocellular Carcinoma Larger than 3 cm: Science, Evidence, and Future Directions

Thermal ablation is widely regarded as definitive therapy for early-stage hepatocellular carcinoma, but its efficacy decreases in tumors greater than 3 cm. Extensive clinical studies have supported improved outcomes provided through combining transarterial embolic therapy with ablation in the treatment of larger tumors. This article will provide a survey of the science and data for combination therapy in both thermal and nonthermal ablation modalities, as well as describe emerging applications.

Efficacy and Safety of Drug-Eluting Beads Transarterial Chemoembolization by CalliSpheres® in 275 Hepatocellular Carcinoma Patients: Results From the Chinese CalliSpheres® Transarterial Chemoembolization in Liver Cancer (CTILC) Study

The purpose of this study was to investigate the efficacy and safety of drug-eluting beads transarterial chemoembolization (DEB-TACE) treatment in Chinese hepatocellular carcinoma (HCC) patients and the prognostic factors for treatment response as well as survival. A total of 275 HCC patients were included in this prospective study. Treatment response was assessed by modified Response Evaluation Criteria in Solid Tumors (mRECIST), and progression-free survival (PFS) as well as overall survival (OS) were determined. Liver function and adverse events (AEs) were assessed before and after DEB-TACE operation. Complete response (CR), partial response (PR), and objective response rate (ORR) were 22.9%, 60.7%, and 83.6%, respectively. The mean PFS was 362 (95% CI: 34.9–375) days, the 6-month PFS rate was 89.4 ± 2.1%, while the mean OS was 380 (95% CI: 370–389) days, and the 6-month OS rate was 94.4 ± 1.7%. Multivariate logistic regression revealed that portal vein invasion (p = 0.011) was an independent predictor of worse clinical response. Portal vein invasion (p = 0.040), previous cTACE treatment (p = 0.030), as well as abnormal serum creatinine level (BCr) (p = 0.017) were independent factors that predicted worse ORR. In terms of survival, higher Barcelona Clinic Liver Cancer (BCLC) stage (p = 0.029) predicted for worse PFS, and abnormal albumin (ALB) (p = 0.011) and total serum bilirubin (TBIL) (p = 0.009) predicted for worse OS. The number of patients with abnormal albumin, total protein (TP), TBIL, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were augmented at 1 week posttreatment and were similar at 1–3 months compared with baseline. The most common AEs were pain, fever, nausea, and vomiting, and no severe AEs were observed in this study. DEB-TACE was effective and tolerable in treating Chinese HCC patients, and portal vein invasion, previous cTACE treatment, abnormal BCr, ALB, and TBIL appear to be important factors that predict worse clinical outcome.

Experimental Study of Retention on the Combination of Bifidobacterium with High-Intensity Focused Ultrasound (HIFU) Synergistic Substance in Tumor Tissues

High intensity focused ultrasound (HIFU) has been recently regarded to be a new type of technique for non-invasive ablation of local tumors and HIFU synergists could significantly improve its therapeutic efficiency. The therapeutic efficiency of HIFU is greatly limited by the low retention of HIFU synergists in the target area and short residence time. This study aimed to explore a method to increase the deposition of HIFU synergists in tumors. Cationic lipid nanoparticle can be used to enhance the HIFU ablation effect, but there is still a problem for it that the deposition amount in the tumor tissue is small and the residence time is short. Bifidobacterium is highly biosafe and can be selectively colonized in the hypoxic zone of tumor tissue. Cationic lipid nanoparticles can be observed in vitro by attachment to bifidobacterium by electrostatic adsorption. And the effect of the proliferation of bifidobacterium in tumor tissues on the retention amount and retention time of cationic lipid nanoparticles in vivo was evaluated. Results showed that the cationic lipid nanoparticles were linked to the surface of Bifidobacterium effectively in vitro, while in vivo, the retention amount and retention time of cationic lipid nanoparticles could be increased by Bifidobacterium in tumor tissues, which provided a new method for improving the therapeutic efficiency of HIFU.

Value of texture analysis based on enhanced MRI for predicting an early therapeutic response to transcatheter arterial chemoembolisation combined with high-intensity focused ultrasound treatment in hepatocellular carcinoma

AIM

To evaluate the potential value of texture analysis (TA) based on contrast-enhanced magnetic resonance imaging (MRI) for predicting an early response of patients with hepatocellular carcinoma (HCC) who were treated with transcatheter arterial chemoembolisation (TACE) combined with high-intensity focused ultrasound (HIFU).

MATERIALS AND METHODS

Patients with HCC (n=89) who underwent contrast-enhanced MRI at 1.5 T 1 week before and 1 week, 1 month, and 3 months after TACE/HIFU were included in this retrospective study. Early responses were evaluated by two radiologists according to the Response Evaluation Criteria in Cancer of the Liver (RECICL). An independent Student's t-test and the Mann-Whitney U-test were used to compare the TA parameters between the complete response (CR) group and the non-complete response (NCR) group. Logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the predictive value of the NCR lesions.

RESULTS

Among the 89 patients, 58 showed CR and 31 showed NCR. Before TACE/HIFU, the CR group showed higher uniformity and energy but lower entropy than the NCR group (p<0.05). After TACE/HIFU, the CR group showed higher uniformity and energy but lower entropy and skewness than the NCR group (p<0.05). The logistic regression and ROC curve analyses showed that the entropy before TACE/HIFU and the skewness and entropy 1 week after TACE/HIFU were predictors of an early response.

CONCLUSION

TA parameters based on contrast-enhanced MRI images 1 week before and after TACE/HIFU may act as imaging biomarkers to predict an early response of patients with HCC.

High intensity focused ultrasound (HIFU) applied to hepato-bilio-pancreatic and the digestive system-current state of the art and future perspectives

BACKGROUND

High intensity focused ultrasound (HIFU) is emerging as a valid minimally-invasive image-guided treatment of malignancies. We aimed to review to current state of the art of HIFU therapy applied to the digestive system and discuss some promising avenues of the technology.

METHODS

Pertinent studies were identified through PubMed and Embase search engines using the following keywords, combined in different ways: HIFU, esophagus, stomach, liver, pancreas, gallbladder, colon, rectum, and cancer. Experimental proof of the concept of endoluminal HIFU mucosa/submucosa ablation using a custom-made transducer has been obtained in vivo in the porcine model.

RESULTS

Forty-four studies reported on the clinical use of HIFU to treat liver lesions, while 19 series were found on HIFU treatment of pancreatic cancers and four studies included patients suffering from both liver and pancreatic cancers, reporting on a total of 1,682 and 823 cases for liver and pancreas, respectively. Only very limited comparative prospective studies have been reported.

CONCLUSIONS

Digestive system clinical applications of HIFU are limited to pancreatic and liver cancer. It is safe and well tolerated. The exact place in the hepatocellular carcinoma (HCC) management algorithm remains to be defined. HIFU seems to add clear survival advantages over trans arterial chemo embolization (TACE) alone and similar results when compared to radio frequency (RF). For pancreatic cancer, HIFU achieves consistent cancer-related pain relief. Further research is warranted to improve targeting accuracy and efficacy monitoring. Furthermore, additional work is required to transfer this technology on appealing treatments such as endoscopic HIFU-based therapies.

Clinical Application of High-intensity Focused Ultrasound in Cancer Therapy

The treatment of cancer is an important issue in both developing and developed countries. Clinical use of ultrasound in cancer is not only for the diagnosis but also for the treatment. Focused ultrasound surgery (FUS) is a noninvasive technique. By using the combination of high-intensity focused ultrasound (HIFU) and imaging method, FUS has the potential to ablate tumor lesions precisely. The main mechanisms of HIFU ablation involve mechanical and thermal effects. Recent advances in HIFU have increased its popularity. Some promising results were achieved in managing various malignancies, including pancreas, prostate, liver, kidney, breast and bone. Other applications include brain tumor ablation and disruption of the blood-brain barrier. We aim at briefly outlining the clinical utility of FUS as a noninvasive technique for a variety of types of cancer treatment.

Hypocrellin B in hepatocellular carcinoma cells: Subcellular localization and sonodynamic damage

PURPOSE

To study subcellular localization of hypocrellin B in hepatocellular carcinoma cells, and hypocrellin B-mediated sonodynamic action-induced cell damage.

MATERIALS AND METHODS

After incubation with 2.5 μM of hypocrellin B, human hepatocellular carcinoma HepG2 cells were exposed to ultrasound waves for 8 sec at an intensity of 0.46 W/cm(2). Clonogenic survival of HepG2 cells was measured using a colony forming assay and light microscope. Ultrastructural morphology was observed using transmission electron microscope (TEM) and mitochondrial membrane potential (MMP) was assessed using confocal laser scanning microcope (CLSM) after rhodamine 123 staining. Additionally, subcellular localization of hypocrellin B in HepG2 cells with organelle probe staining was also observed using CLSM.

RESULTS

The colony forming units of HepG2 cells decreased substantially after sonodynamic treatment. The results of TEM showed microvilli disappearance, apoptotic body formation, swollen mitochondria with loss of cristae and mitochondrial myelin-like features (or membrane whorls). Collapse of MMP was found in the treated cells. Hypocrellin B was distributed in mitochondria and lysosomes as well as in endoplasmic reticulum and Golgi apparatus.

CONCLUSIONS

The findings demonstrated that sonodynamic action of hypocrellin B induced mitochondrial damage, survival inhibition, and apoptosis of HepG2 cells. Additionally, other subcellular organelles such as endoplasmic reticulum, Golgi apparatus and lysosomes were also the targets of hypocrellin B-mediated sonodynamic action as well as mitochondria.

Effective strategy of the combination of high-intensity focused ultrasound and transarterial chemoembolization for improving outcome of unresectable and metastatic hepatoblastoma: a retrospective cohort study

The combination of high-intensity focused ultrasound (HIFU) and transarterial chemoembolization (TACE) has been experimentally performed in a variety of malignant tumors, and its validity has not yet been evaluated for hepatoblastoma (HB). We evaluated the disease-response rate, resection rate, and toxicity in children with unresectable or metastatic HB (stage III and stage IV HB) after sequential treatment with TACE plus HIFU in a controlled clinical trial. The 35 patients with unresectable or metastatic HB were nonrandomly assigned to HIFU ablation (n = 12) or C5V chemotherapy (n = 23). The rates of complete resection, tumor response, and treatment toxicity were evaluated for both regimens. Nine patients who received C5V and 10 patients who received TACE plus HIFU became operable (P = .02). The 3-year event-free survival and overall survival rates were 43.03% and 56.68% in the C5V group and 38.57% and 57.86% in the TACE plus HIFU group, respectively. Acute grade 3 or 4 adverse events, including neutropenia, thrombocytopenia, and anemia, were more frequent in patients treated with C5V therapy than in patients receiving TACE plus HIFU. HIFU ablation achieved a higher rate of complete resection and a lower rate of severe complications compared with C5V treatment in children with advanced HB (Chinese Clinical Trials Registry No. ChiCTR-PRCH-08000182).

Comparison of percutaneous ablation technologies in the treatment of malignant liver tumors

Tumor ablation is a minimally invasive technique used to deliver chemical, thermal, electrical, or ultrasonic damage to a specific focal tumor in an attempt to achieve substantial tumor destruction or complete eradication. As the technology continues to advance, several image-guided tumor ablations have emerged to effectively manage primary and secondary malignancies in the liver. Percutaneous chemical ablation is one of the oldest and most established techniques for treating small hepatocellular carcinomas. However, this technique has been largely replaced by newer modalities including radiofrequency ablation, microwave ablation, laser-induced interstitial thermotherapy, cryoablation, high-intensity-focused ultrasound ablation, and irreversible electroporation. Because there exist significant differences in underlying technological bases, understanding each mechanism of action is essential for achieving desirable outcomes. In this article, the authors review the current state of each ablation method including technological and clinical considerations.

Extracorporeal ultrasound-guided high intensity focused ultrasound: implications from the present clinical trials

Extracorporeal ultrasound-guided high intensity focused ultrasound (HIFU) has been clinically used for 15 years, and over 36000 cases have been reported. However, there yet lacked a consensus in the clinical values, suggesting the necessity of checking clinical findings. Clinical trials were searched and data reevaluated. HIFU was hardly performed alone; almost all present anticancer means have been applied during an HIFU treatment, and a specific regimen varied between trials; there were heterogeneity and disagreement between trials. The complexity made it difficult to distinguish the effect of HIFU. Based upon evaluable data, the efficacy of HIFU was similar to that of radio frequency, chemoembolization, chemotherapy, radiotherapy, or hormone therapy; a combined therapy did not improve the efficacy. The survival rate of HIFU plus radiotherapy was lower than that of radical surgery in liver cancers. Adverse events had no downtrend in the past years. HIFU was not a standardized procedure where the intensity and insonation mode were modified constantly throughout a treatment, limiting an evaluation from the perspective of ultrasonics. These implied that HIFU should be applied as an alternative at most occasions. The present clinical trials had defects making against the understating of HIFU.

First experience of high-intensity focused ultrasound combined with transcatheter arterial embolization as local control for hepatoblastoma

The purpose of this study was to assess the effectiveness of high-intensity focused ultrasound (HIFU) combined with transarterial chemoembolization (TACE) in treating pediatric hepatoblastoma. Twelve patients with initially unresectable hepatoblastoma were enrolled in the study. All patients received chemotherapy, TACE, and HIFU ablation. Follow-up materials were obtained in all patients. The tumor response, survival rate, and complications were analyzed. Complete ablation was achieved in 10 patients (83.3%), and the alpha-fetoprotein level was also decreased to normal in these patients. The mean follow-up time was 13.3 ± 1.8 months (range, 2-25 months). At the end of follow-up, two patients died from tumor progression, the other 10 patients were alive. One patient was found to have lung metastasis after HIFU and had an operation to remove the lesion. The median survival time was 14 months, and the 1- and 2-year survival rates were 91.7% and 83.3%, respectively. Complications included fever, transient impairment of hepatic function, and mild malformation of ribs.

CONCLUSION

HIFU combined with TACE is a safe and promising method with a low rate of severe complications. As a noninvasive approach, it may provide a novel local therapy for patients with unresectable hepatoblastoma.

High intensity focused ultrasound, liver disease and bridging therapy

High-intensity focused ultrasound (HIFU) is a non-invasive modality that uses an extracorporeal source of focused ultrasound energy. This technique was introduced by Lynn et al and is able to induce coagulative necrosis in selected tissues without damaging adjacent structures. Although HIFU has been studied for 50 years, recent technological developments now allow its use for tumours of the liver, prostate and other sites. In liver disease, HIFU has been used to treat unresectable, advanced stages of hepatocellular carcinoma (HCC) and liver metastases. Hepatocellular carcinoma is a serious health problem worldwide and is endemic in some areas because of its association with hepatitis B and C viruses (in 20% of cases). Liver transplantation (LT) has become one of the best treatments available because it removes both the tumour and the underlying liver disease such as cirrhosis (which is present in approximately 80% of cases). The prerequisite for long-term transplant success depends on tumour load and strict selection criteria regarding the size and number of tumour nodules. The need to obtain the optimal benefit from the limited number of organs available has prompted strict selection criteria limited to only those patients with early HCC who have a better long-term outcome after LT. The so-called “bridging therapy” has the aim of controlling disease burden for patients who are on the organ transplant waiting list. Amongst various treatment options, transarterial chemoembolisation and radiofrequency ablation are the most popular treatment choices. Recently, Cheung et al demonstrated that HIFU ablation is a safe and effective method for the treatment of HCC patients with advanced cirrhosis as a bridging therapy and that it reduced the dropout rate from the liver transplant waiting list. In this commentary, we discuss the current value of HIFU in the treatment of liver disease, including its value as a bridging therapy, and examine the potential advantages of other therapeutic strategies.

Pulsed high-intensity focused ultrasound enhances apoptosis of pancreatic cancer xenograft with gemcitabine

We sought to investigate whether concurrent exposure to pulsed high-intensity focused ultrasound (HIFU) and the chemotherapeutic drug gemcitabine would enhance apoptosis in pancreatic cancer. A pancreatic cancer xenograft model was established using BALB/c nude mice and human pancreatic cancer cells (PANC-1). In the first study, mice were randomly allocated into one of four groups: control (n = 4), HIFU alone (n = 4), gemcitabine (GEM) alone (n = 28) and concurrent treatment with HIFU and gemcitabine (HIGEM) (n = 28). The GEM and HIGEM groups were subdivided into four subgroups (16 mice) according to the drug dose injected (50-200 mg/kg) and another four subgroups (16 mice) according to the time interval between drug injection and HIFU treatment (each subgroup, n = 4). Apoptosis rates were evaluated using the TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) assay and percentage of necrosis, as evaluated with Harris' hematoxylin solution and eosin Y stain, 3 d after treatment. The second study was performed to evaluate tumor growth rates of the four groups. Each group was treated weekly for 3 wk, and tumor size was periodically measured for up to 4 wk from the beginning of treatment. In the first study, overall rates of apoptosis were significantly higher in the HIGEM group than in the GEM group (p = 0.02). In a subgroup analysis, HIGEM was superior to GEM in enhancing apoptosis at gemcitabine dosages of 150-200 mg/kg gemcitabine and intervals between gemcitabine and HIFU less than 2 h (p = 0.01). In the second study, HIGEM treatment resulted in the slowest tumor growth. However, despite a visible distinction, none of the differences found between the HIGEM and GEM groups were statistically significant (p > 0.05). Treatment with both HIFU and gemcitabine might enhance cell apoptosis and reduce tumor growth in pancreatic carcinoma. For this concurrent treatment, a high dosage of gemcitabine and a short-term delay before HIFU are recommended to maximize the therapeutic effect.

Hepatocellular carcinoma: Clinical study of long-term survival and choice of treatment modalities

AIM: To analyze the prognostic factors of 5-year survival and 10-year survival in hepatocellular carcinoma (HCC) patients, and to explore the reasons for long-term survival and provide choice of treatment modalities for HCC patients.

METHODS: From January 1990 to October 2012, 8450 HCC patients were included in a prospective database compiled by the Information Center after hospital admission. Long-term surviving patients were included in a 10-year survival group (520 patients) and a 5-year survival group (1516 patients) for analysis.The long-term survival of HCC patients was defined as the survival of 5 years or longer. Clinical and biologic variables were assessed using univariate and multivariate analyses. The survival of patients was evaluated by follow-up data.

RESULTS: The long-term survival of HCC patients was associated with the number of lesions, liver cirrhosis and Child-Pugh classification. It was not found to be associated with tumor diameter, histological stage, and pretreatment level of serum α-fetoprotein. The differences in clinical factors between the 5-year survival and the 10-year survival were found to be the number of lesions, liver cirrhosis, Child-Pugh classification, and time elapsed until first recurrence or metastasis. The survival period of different treatment modalities in the patients who survived for 5 years and 10 years showed significant differences: (in order of significance) surgery alone > surgery-transcatheter arterial chemoembolization (TACE) > TACE-radiofrequency ablation (RFA) > TACE alone > surgery-TACE-RFA. The 10-year survival of HCC patients was not associated with the choice of treatment modality.

CONCLUSION: This retrospective study elucidated survival outcomes, prognostic factors affecting survival and treatment modalities in HCC patients.

Survival analysis of high-intensity focused ultrasound therapy versus radiofrequency ablation in the treatment of recurrent hepatocellular carcinoma

OBJECTIVE

To evaluate our preliminary experience of high-intensity focused ultrasound (HIFU) for the treatment of recurrent hepatocellular carcinoma (HCC).

BACKGROUND

HIFU is a new thermal ablative therapy for HCC. Whether it incurs survival benefit similar to that of radiofrequency ablation (RFA) remains uncertain.

METHODS

Clinicopathological data of 27 patients who received HIFU ablation and 76 patients who received RFA for recurrent HCC from October 2006 to October 2009 were reviewed. Survival outcomes between the 2 groups were compared using the log-rank test. A value of P < 0.05 was considered significant.

RESULTS

The median follow-up was 27.9 months. There was no difference in tumor size (HIFU, 1.7 cm; RFA, 1.8 cm; P = 0.28) between the 2 groups. Procedure-related morbidity rate was 7.4% in the HIFU group and 6.5% in the RFA group (P = 1.00). Skin burn and pleural effusion were the 2 morbidities associated with HIFU. There was no hospital mortality in the HIFU group, whereas 2 deaths occurred in the RFA group. The 1-, 2-, and 3-year disease-free survival rates were 37.0%, 25.9%, and 18.5%, respectively, for the HIFU group, and 48.6%, 32.1%, and 26.5%, respectively for the RFA group (P = 0.61). The 1-, 2-, and 3-year overall survival rates were 96.3%, 81.5%, and 69.8%, respectively, for the HIFU group, and 92.1%, 76.1%, and 64.2%, respectively, for the RFA group (P = 0.19).

CONCLUSIONS

Our preliminary experience in using HIFU for recurrent HCC is promising. Further studies are needed to explore its treatment value for primary HCC.

High-intensity focused ultrasound: advances in technology and experimental trials support enhanced utility of focused ultrasound surgery in oncology

High-intensity focused ultrasound (HIFU) is a rapidly maturing technology with diverse clinical applications. In the field of oncology, the use of HIFU to non-invasively cause tissue necrosis in a defined target, a technique known as focused ultrasound surgery (FUS), has considerable potential for tumour ablation. In this article, we outline the development and underlying principles of HIFU, overview the limitations and commercially available equipment for FUS, then summarise some of the recent technological advances and experimental clinical trials that we predict will have a positive impact on extending the role of FUS in cancer therapy.

Magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) ablation of liver tumours

Recent decades have seen a paradigm shift in the treatment of liver tumours from invasive surgical procedures to minimally invasive image-guided ablation techniques. Magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) is a novel, completely non-invasive ablation technique that has the potential to change the field of liver tumour ablation. The image guidance, using MR imaging and MR temperature mapping, provides excellent planning images and real-time temperature information during the ablation procedure. However, before clinical implementation of MR-HIFU for liver tumour ablation is feasible, several organ-specific challenges have to be addressed. In this review we discuss the MR-HIFU ablation technique, the liver-specific challenges for MR-HIFU tumour ablation, and the proposed solutions for clinical translation.