High-intensity focused ultrasound treatment for patients with unresectable pancreatic cancer

Study Protocol of a Randomized, Two-Arm, Phase I/II Trial Investigating the Feasibility, Safety, and Efficacy of Local Treatment with US-Guided High-Intensity Focused Ultrasound in Combination with Palliative Chemotherapy in Inoperable Pancreatic Cancer

BACKGROUND

Pancreatic adenocarcinoma (PaC) still has a dismal prognosis, and despite medical advances, a bleak 5-year survival rate of only 8%, largely due to late diagnosis and limited curative surgical options for most patients. Frontline palliative treatment shows some survival advantages. However, the high disease mortality is accompanied by high morbidity including cancer-related pain and additional symptoms, which strongly impair patients' quality of life (QOL). At present, there is no established strategy for local therapy for PaC primarily aiming to manage local tumor growth and alleviate associated symptoms, particularly pain. In recent years, non-invasive high-intensity focused ultrasound (HIFU) has shown promising results in reducing cancer pain and tumor mass, improving patients' QOL with few side effects.

STUDY DESIGN

This is the first randomized controlled trial worldwide including 40 patients with inoperable pancreatic adenocarcinoma randomized into two groups: group A undergoing standard chemotherapy; and group B undergoing standard chemotherapy plus local HIFU treatment. This study aims to establish a robust evidence base by examining the feasibility, safety, and efficacy of US-guided HIFU in combination with standard palliative systemic therapy for unresectable PaC. Primary endpoint assessments will focus on parameters including safety issues (phase I), and local response rates (phase II).

Repeated high‑intensity focused ultrasound combined with iodine‑125 seed interstitial brachytherapy offers improved quality of life and pain control for patients with advanced pancreatic cancer: A 52‑patient retrospective study

Patients diagnosed with pancreatic cancer who have 5-year survival rates of ~5% are typically in the advanced stage. Pancreatic cancer has become the third leading cause of cancer-related death in the United States and there is still a lack of effective treatments to improve patient survival rate. Hence, the purpose of the present retrospective study was to assess the potential clinical impact of repeated high-intensity focused ultrasound (HIFU) combined with iodine-125 (125I) interstitial brachytherapy for the treatment of patients with advanced pancreatic cancer who were ineligible for or declined surgery and chemotherapy. A total of 52 patients diagnosed with advanced pancreatic cancer were included in the study. At least one course of HIFU therapy combined with percutaneous ultrasound-guided 125I seed implantation was administered to each patient. The clinical assessment included an evaluation of Karnofsky Performance Scale (KPS) score at baseline, and at 1 and 2 months after combined therapy. Pain intensity was additionally evaluated with the numerical rating score (NRS). Overall survival (OS) times and survival rates at 3, 6, 9 and 12 months after combined treatment were evaluated. Adverse events commonly associated with HIFU and 125I seed implantation were recorded, and the severity of adverse events was graded according to the Common Terminology Criteria for Adverse Events, version 4. All 52 patients received successful repeated HIFU treatment combined with 125I seed implantation and were included in the analysis of efficacy and safety. The median OS time of patients was estimated to be 13.1 months (95% CI, 11.3-14.8). The survival rates at 3, 6, 9 and 12 months were 100.0, 86.5, 61.5 and 53.8%, respectively. The mean KPS score was 62.7±6.3 at baseline, 73.7±7.9 at 1 month and 68.8±6.5 at 2 months after combined treatment. KPS score increased significantly after combined therapy. The mean NRS score was 6.7±1.6 at baseline, and 4.7±1.7 and 5.4±1.5 at 1 and 2 months after combined treatment, respectively. The number of patients with severe pain and the NRS score were both significantly lower at 1 and 2 months after 125I seed implantation compared with those at baseline. No serious complications were detected during the follow-up period. In conclusion, the present study demonstrated the survival benefit and improvement in quality of life of patients with advanced pancreatic cancer receiving repeated HIFU treatment combined with 125I interstitial brachytherapy, which may provide new ideas and methods for the treatment of pancreatic cancer.

US-guided high-intensity focused ultrasound in pancreatic cancer treatment: a consensus initiative between Chinese and European HIFU centers

Purpose: Ultrasound-guided high-intensity focused ultrasound (USgHIFU) represents a safe and effective non-invasive thermoablative technique for managing inoperable pancreatic cancer. This treatment method significantly alleviates disease-related symptoms and reduces pancreatic tumor volume. However, the current body of evidence is constrained by a lack of randomized controlled trials. The utilization of USgHIFU is primarily indicated for patients with unresectable, locally advanced, or metastatic pancreatic cancer, particularly those experiencing symptoms due to a locally advanced primary tumor.Methods: This collaborative consensus paper, involving European and Chinese HIFU centers treating pancreatic cancer, delineates criteria for patient selection, focusing on those most likely to benefit from USgHIFU treatment. Consideration is given to endpoints encompassing symptom alleviation, local response rates, other oncological outcomes, as well as overall and progression-free survival. Additionally, this paper defines relevant contraindications, side effects, and complications associated with USgHIFU. The publication also explores the feasibility and role of USgHIFU within the context of palliative care, including standard systemic chemotherapy.Results: The non-invasive local treatment of advanced pancreatic cancer using HIFU should be regarded as an adjunctive option alongside systemic chemotherapy or best supportive care for managing this aggressive disease. Based on the ability of USgHIFU therapy to mitigate pain and reduce primary tumor volume, it should be considered as a complementary therapy for symptomatic patients with inoperable pancreatic cancer and as a potential means of tumor debulking. The underutilized yet promising USgHIFU exhibits the potential to enhance patients' quality of life by alleviating cancer-related pain. Experts in the field should evaluate this treatment option be evaluated by experts in this field, with this consensus paper potentially serving as a guiding resource for the medical community.Conclusions: US-guided HIFU for advanced pancreatic cancer addresses treatment goals, available options, success rates, and limitations. As a non-invasive, effective local therapy, complementary to chemotherapy and best supportive care, it plays a pivotal role in pain relief, reducing of tumor volume, and potentially improving survival rates.

EUS-guided ablation with the HybridTherm Probe as second-line treatment in patients with locally advanced pancreatic ductal adenocarcinoma: A case-control study

Background and Objectives

Data on the clinical efficacy of EUS-guided ablation using the HybridTherm-Probe (EUS-HTP) in locally advanced pancreatic ductal adenocarcinoma (LA-PDAC) are lacking. The aim of the study was to assess the impact of EUS-HTP added to chemotherapy (CT) on overall survival (OS) and progression-free survival (PFS) of LA-PDAC patients with local disease progression (DP) after first-line therapy, compared to CT alone in controls.

Methods

LA-PDAC cases, prospectively treated by EUS-HTP, were retrospectively compared to matched controls (1:2) receiving standard treatment. Study endpoints were the OS and PFS from local DP after first-line therapy, compared through log-rank test calculating hazard ratios and differences in restricted mean OS/PFS time (RMOST/RMPFST) within prespecified time points (4, 6, and 12 months).

Results

Thirteen cases and 26 controls were included. Clinical, tumor, and therapy features before and after first-line therapy were case-control balanced. The median OS and PFS were not significantly improved in cases over controls (months: 7 vs. 5 and 5 vs. 3, respectively). At 4 and 6 months, the RMPFST difference was in favor of cases (P = 0.0001 and P = 0.003, respectively). In cases and controls not candidate to further CT (N = 5 and N = 9), the median OS and PFS were not significantly improved in cases over controls (months: 6 vs. 3 and 4 vs. 2, respectively), but the RMPFST difference was in favor of cases at 4 months (P = 0.002).

Conclusions

In locally progressive PDAC patients experiencing failure of first-line therapy, EUS-HTP achieves a significantly better RMPFST up to 6 months compared to standard treatment, although without a significant impact on OS.

Low frequency nanobubble-enhanced ultrasound mechanotherapy for noninvasive cancer surgery

Scaling down the size of microbubble contrast agents to the nanometer level holds the promise for noninvasive cancer therapy. However, the small size of nanobubbles limits the obtained bioeffects as a result of ultrasound cavitation, when operating near the nanobubble resonance frequency. Here we show that coupled with low energy insonation at a frequency of 80 kHz, well below the resonance frequency of these agents, nanobubbles serve as noninvasive therapeutic warheads that trigger potent mechanical effects in tumors following a systemic injection. We demonstrate these capabilities in tissue mimicking phantoms, where a comparison of the acoustic response of micro- and nano-bubbles after insonation at a frequency of 250 or 80 kHz revealed that higher pressures were needed to implode the nanobubbles compared to microbubbles. Complete nanobubble destruction was achieved at a mechanical index of 2.6 for the 250 kHz insonation vs. 1.2 for the 80 kHz frequency. Thus, the 80 kHz insonation complies with safety regulations that recommend operation below a mechanical index of 1.9. In vitro in breast cancer tumor cells, the cell viability was reduced to 17.3 ± 1.7% of live cells. In vivo, in a breast cancer tumor mouse model, nanobubble tumor distribution and accumulation were evaluated by high frequency ultrasound imaging. Finally, nanobubble-mediated low frequency insonation of breast cancer tumors resulted in effective mechanical tumor ablation and tumor tissue fractionation. This approach provides a unique theranostic platform for safe, noninvasive and low energy tumor mechanotherapy.

High-intensity focused ultrasound therapy for pancreatic cancer

Pancreatic cancer (PC) has one of the poorest prognoses among solid cancers, and its incidence has increased recently. Satisfactory outcomes are not achieved with current therapies; thus, novel treatments are urgently needed. High-intensity focused ultrasound (HIFU) is a novel therapy for ablating tissue from the outside of the body by focusing ultrasonic waves from multiple sources on the tumor. In this therapy, only the focal area is heated to 80-100 ºC, which causes coagulative necrosis of the tissue, with hardly any impact on the tissue outside the focal area. Although HIFU is a minimally invasive treatment and is expected to be useful, it is not yet generally known. Here, we discuss the usefulness of HIFU treatment for un-resectable advanced PC using the results of previous research, meta-analyses, and systematic reviews on its efficacy and safety. HIFU therapy for un-resectable PC is useful for its anti-tumor effect and pain relief, and is expected to prolong survival time and improve quality of life. Although HIFU for PC has several limitations and further study is needed, this technique can be safely performed on un-resectable advanced PC. In future, HIFU could be utilized as a minimally invasive treatment strategy for PC patients with a poor prognosis.

A meta-analysis evaluating the role of high-intensity focused ultrasound (HIFU) as a fourth treatment modality for patients with locally advanced pancreatic cancer

BACKGROUND

This study aimed to evaluate the outcomes of high-intensity focused ultrasound (HIFU) on patients with advanced pancreatic cancer.

METHODS

A literature search was performed in PubMed, Scopus and Cochrane databases, in accordance with the PRISMA guidelines. The Odds Ratio, Weighted Mean Difference, and 95% Confidence Interval were evaluated by means of the Random-Effects model.

RESULTS

Nineteen articles met the inclusion criteria, incorporating 939 patients. This study reveals that patients in the HIFU group presented increased median overall survival (OS), along with higher OS at 6 and 12 months after treatment compared with the control group (p < 0.05). Furthermore, patients treated with HIFU in conjunction with chemotherapy presented reduced levels of pain (p < 0.05) compared to the traditional treatment group. In addition, HIFU contributed to significant tumor responsiveness, in terms of CA19-9 reduction (p < 0.05). Finally, HIFU was a considerably safe treatment modality with a low incidence of complications.

CONCLUSION

These outcomes suggest that HIFU is a feasible and safe treatment modality for patients with advanced pancreatic cancer and provides enhanced outcomes regarding survival and quality of life. Given the lack of a significant number of randomized clinical trials, this meta-analysis represents the best currently available evidence. New randomized trials assessing HIFU are necessary to further evaluate their outcomes.

Novel Therapeutic Method for Unresectable Pancreatic Cancer-The Impact of the Long-Term Research in Therapeutic Effect of High-Intensity Focused Ultrasound (HIFU) Therapy

High-intensity focused ultrasound (HIFU) is a novel advanced therapy for unresectable pancreatic cancer (PC). HIFU therapy with chemotherapy is being promoted as a novel method to control local advancement by tumor ablation. We evaluated the therapeutic effects of HIFU therapy in locally advanced and metastatic PC. PC patients were treated with HIFU as an optional local therapy and systemic chemotherapy. The FEP-BY02 (Yuande Bio-Medical Engineering) HIFU device was used under ultrasound guidance. Of 176 PC patients, 89 cases were Stage III and 87 were Stage IV. The rate of complete tumor ablation was 90.3%, while that of symptom relief was 66.7%. The effectiveness on the primary lesions were as follows: complete response (CR): n = 0, partial response (PR): n = 21, stable disease (SD): n = 106, and progressive disease (PD): n = 49; the primary disease control rate was 72.2%. Eight patients underwent surgery. The median survival time (MST) after diagnosis for HIFU with chemotherapy compared to chemotherapy alone (100 patients in our hospital) was 648 vs. 288 days (p < 0.001). Compared with chemotherapy alone, the combination of HIFU therapy and chemotherapy demonstrated significant prolongation of prognosis. This study suggests that HIFU therapy has the potential to be a novel combination therapy for unresectable PC.

Is high-intensity focused ultrasound (HIFU) an option for neoadjuvant therapy for borderline resectable pancreatic cancer patients? - a systematic review

INTRODUCTION

Pancreatic cancer is with the poorest prognosis of all common cancers worldwide. Despite the advances in treatment the results are poor throughout the different methods. Pancreatic resection still yields the best outcome. However only a quarter of the patients present at operable stage. HIFU is a noninvasive technique that can be used to treat pancreatic cancer.

AIM

The aim of this review is to perform a systematic review on the data about the resection rate after HIFU ablation in patients with borderline resectable pancreatic cancer (BRPC) and the impact of this technique over the oncological results.

MATERIALS AND METHODS

The PubMed and Wanfang databases were searched using keywords: pancreatic cancer, HIFU ablation and high-intensity focused ultrasound. All found articles were reviewed. The systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standard guidelines. This study was financially supported by 2019 'Kuan-Ren Elite' Program of 2nd Affiliated Hospital of Chongqing Medical University, China (Grant no. KY2019G019).

RESULTS

The English database search showed 109 papers, of which 3 met the inclusion criteria. The Wanfang database resulted in 110 papers; however, none met the inclusion criteria of the review. From the included studies 97 patients underwent neoadjuvant HIFU ablation ± chemotherapy. Thirty-four patients reached resection (35.1%). In two patients, residual tumor (R) classification was not reported. R0 resection rate in all reported patients is 30.5% (29/95). R1 resection rate is 3.2% (3/95).

CONCLUSION

HIFU is found to be safe and feasible in locally advanced and metastatic pancreatic cancer with proven downstaging and downsizing effects. Further research on role of HIFU ablation as a neoadjuvant treatment for borderline resectable pancreatic cancer is needed.

Acoustically Detonated Microbubbles Coupled with Low Frequency Insonation: Multiparameter Evaluation of Low Energy Mechanical Ablation

Noninvasive ultrasound surgery can be achieved using focused ultrasound to locally affect the targeted site without damaging intervening tissues. Mechanical ablation and histotripsy use short and intense acoustic pulses to destroy the tissue via a purely mechanical effect. Here, we show that coupled with low-frequency excitation, targeted microbubbles can serve as mechanical therapeutic warheads that trigger potent mechanical effects in tumors using focused ultrasound. Upon low frequency excitation (250 kHz and below), high amplitude microbubble oscillations occur at substantially lower pressures as compared to higher MHz ultrasonic frequencies. For example, inertial cavitation was initiated at a pressure of 75 kPa for a center frequency of 80 kHz. Low frequency insonation of targeted microbubbles was then used to achieve low energy tumor cell fractionation at pressures below a mechanical index of 1.9, and in accordance with the Food and Drug Administration guidelines. We demonstrate these capabilities in vitro and in vivo. In cell cultures, cell viability was reduced to 16% at a peak negative pressure of 800 kPa at the 250 kHz frequency (mechanical index of 1.6) and to 10% at a peak negative pressure of 250 kPa at a frequency of 80 kHz (mechanical index of 0.9). Following an intratumoral injection of targeted microbubbles into tumor-bearing mice, and coupled with low frequency ultrasound application, significant tumor debulking and cancer cell death was observed. Our findings suggest that reducing the center frequency enhances microbubble-mediated mechanical ablation; thus, this technology provides a unique theranostic platform for safe low energy tumor fractionation, while reducing off-target effects.

Focused Ultrasound (FUS) for Chronic Pain Management: Approved and Potential Applications

Chronic pain is one of the leading causes of disability and disease burden worldwide, accounting for a prevalence between 6.9% and 10% in the general population. Pharmacotherapy alone results ineffective in about 70-60% of patients in terms of a satisfactory degree of pain relief. Focused ultrasound is a promising tool for chronic pain management, being approved for thalamotomy in chronic neuropathic pain and for bone metastases-related pain treatment. FUS is a noninvasive technique for neuromodulation and for tissue ablation that can be applied to several tissues. Transcranial FUS (tFUS) can lead to opposite biological effects, depending on stimulation parameters: from reversible neural activity facilitation or suppression (low-intensity, low-frequency ultrasound, LILFUS) to irreversible tissue ablation (high-intensity focused ultrasounds, HIFU). HIFU is approved for thalamotomy in neuropathic pain at the central nervous system level and for the treatment of facet joint osteoarthritis at the peripheral level. Potential applications include HIFU at the spinal cord level for selected cases of refractory chronic neuropathic pain, knee osteoarthritis, sacroiliac joint disease, intervertebral disc nucleolysis, phantom limb, and ablation of peripheral nerves. FUS at nonablative dosage, LILFUS, has potential reversible and tissue-selective effects. FUS applications at nonablative doses currently are at a research stage. The main potential applications include targeted drug and gene delivery through the Blood-Brain Barrier, assessment of pain thresholds and study of pain, and reversible peripheral nerve conduction block. The aim of the present review is to describe the approved and potential applications of the focused ultrasound technology in the field of chronic pain management.

Stent Insertion With High Intensity-Focused Ultrasound Ablation for Biliary Obstruction Caused by Pancreatic Carcinoma: A Randomized Controlled Trial

PURPOSE

This study was designed to assess the clinical efficacy of stent insertion with high intensity-focused ultrasound ablation (HIFUA) in patients with malignant biliary obstruction (MBO) as a consequence of pancreatic carcinoma (PC).

MATERIALS AND METHODS

This was a single-center, open-label, prospective, randomized controlled trial. Consecutive patients with MBO caused by PC were randomly assigned to undergo stent insertion with or without HIFUA from June 2019 to February 2020. This study was registered at ClinicalTrials.gov (NCT03962478).

RESULTS

In total, 92 patients were enrolled in this study and assigned to the stent-only (n=46) or combined (stent+HIFUA; n=46) treatment groups. Stent insertion was associated with a 100% technical success rate. For patients in the combination treatment group, 26, 18, and 2 patients underwent 2, 3, and 4 cycles of HIFUA, respectively. A positive clinical response to HIFUA treatment was noted in 38 patients (82.6%). Stent dysfunction was detected in 9 and 15 patients in the combination and stent-only groups, respectively (P=0.154), while median stent patency in these 2 groups was 188 and 120 days, respectively (P<0.001). All patients died over the course of the follow-up, with median survival periods of 218 and 140 days in the combination and stent-only treatment groups, respectively (P=0.001). The only detected predictor of prolonged survival was HIFUA treatment (P=0.004), and there were no significant differences in complication rates between these 2 treatment groups.

CONCLUSION

A combination of stent insertion and HIFUA can improve stent patency and overall survival in patients suffering from MBO because of PC relative to stent insertion alone.

Improving quality of life in pancreatic cancer patients following high-intensity focused ultrasound (HIFU) in two European centers

OBJECTIVES

Pancreatic cancer patients often have a high symptom burden, significantly impairing patients' quality of life (QOL). Nevertheless, there are hardly any reports on the impact of high-intensity focused ultrasound (HIFU) on the QOL of treated patients. For the first time, this study evaluated the effect of HIFU on QOL and compared these results in two European centers.

METHODS

Eighty patients with advanced pancreatic cancer underwent HIFU (50 in Germany, 30 in Bulgaria). Clinical assessment included evaluation of QOL and symptoms using the EORTC QLQ-C30 questionnaire at baseline and 1, 3, and 6 months after HIFU. Pain intensity was additionally evaluated with the numerical rating score (NRS).

RESULTS

Compared to baseline, global health significantly improved 3 and 6 months after HIFU treatment (p = 0.02). Functional subscales including physical, emotional, and social functioning were considerably improved at 6 months (p = 0.02, p = 0.01, and p = 0.01, respectively) as were leading symptom pain (p = 0.04 at 6 months), fatigue (p = 0.03 at 3 and p = 0.01 at 6 months), and appetite loss (p = 0.01 at 6 months). Moreover, pain intensity measured by NRS revealed effective and strong pain relief at all time points (p < 0.001). Reported effects were independent of tumor stage, metastatic status, and country of treatment.

CONCLUSIONS

This study showed that HIFU represents an effective treatment option of advanced pancreatic cancer improving QOL by increasing global health and mitigation of physical complaints with a low rate of side effects, independent of the examiner. Therefore, HIFU is a worthwhile additional treatment besides systemic palliative chemotherapy or best supportive care in management of this aggressive disease.

KEY POINTS

• In a prospective two-center study, it was shown that HIFU represents an effective treatment option of advanced pancreatic cancer improving QOL. • HIFU in pancreatic cancer patients is associated with a low rate of side effects, independent of the performer. • HIFU is a worthwhile additional treatment besides systemic palliative chemotherapy or best supportive care in management of this aggressive disease.

Effect of Pulsed Focused Ultrasound on the Native Pancreas

Pulsed focused ultrasound (pFUS) utilizes short cycles of sound waves to mechanically shake cells within tissues which, in turn, causes transient local increases in cytokines, growth factors and cell adhesion molecules. Although the effect of pFUS has been investigated in several different organs including the kidney, muscle and heart, its effect on the pancreas has not been investigated. In the present work, we applied pFUS to the rodent pancreas with the following parameters: 1.1-MHz frequency, 5-Hz pulse repetition frequency, 5% duty cycle, 10-ms pulse length, 160-s duration. Low-intensity pFUS had a spatial average temporal average intensity of 11.5 W/cm² and a negative peak pressure of 3 MPa; high-intensity pFUS had a spatial average temporal average intensity of 18.5 W/cm² and negative peak pressure of 4 MPa. Here we found that pFUS changed the expression of several cytokines while having no effect on the underlying tissue histology or health of pancreatic cells (as reflected by no significant change in plasma levels of amylase and lipase). Furthermore, we found that this effect on cytokine expression in the pancreas was acoustic intensity dependent; while pFUS at low intensities turned off the expression of several cytokines, at high intensities it had the opposite effect and turned on the expression of these cytokines. The ability to non-invasively manipulate the microenvironment of the pancreas using sound waves could have profound implications for priming and modulating this organ for the application of cellular therapies in the context of both regenerative medicine (i.e., diabetes and pancreatitis) and oncology (i.e., pancreatic cancer).

Stent insertion with high-intensity focused ultrasound ablation for distal biliary obstruction secondary to pancreatic carcinoma

We determined the clinical effectiveness and long-term outcomes in patients with distal biliary obstruction (DBO) secondary to pancreatic carcinoma (PC) who were treated by self-expanded metallic stent (SEMS) insertion with or without high-intensity focused ultrasound (HIFU) ablation.From January 2014 to December 2018, consecutive patients with DBO secondary to PC underwent SEMS insertion with or without HIFU ablation in our center. The long-term outcomes were compared between the 2 groups.During the included period, 75 patients underwent SEMS insertion with (n = 34) or without (n = 41) HIFU ablation in our center. SEMS insertion was successfully performed in all patients. Liver function was significantly improved after SEMS insertion in both groups. An average of 2.9 HIFU treatment sessions per patient were performed. Twenty patients (stent + HIFU group: 7; stent-only group: 13) experienced stent dysfunction (P = .278). The clinical response rate to HIFU ablation was 79.4%. The median stent patency was significantly longer in the stent with HIFU group than in the stent-only group (175 vs 118 days, P = .005). The median survival was significantly longer in the stent with HIFU group compared with the stent-only group (211 versus 136 days, P = .004). An Eastern Cooperative Oncology Group (ECOG) Performance Status of 3 (hazard ratio: 0.300; P = .002) and subsequent HIFU ablation (hazard ratio: 0.508; P = .005) were associated with prolonged survival.HIFU ablation following stent insertion can prolong the stent patency and survival for patients with DBO secondary to PC.

A Retrospective Case Series Of High-Intensity Focused Ultrasound (HIFU) In Combination With Gemcitabine And Oxaliplatin (Gemox) On Treating Elderly Middle And Advanced Pancreatic Cancer

Purpose

This retrospective study was conducted to evaluate the safety and efficacy of high-intensity focused ultrasound (HIFU) ablation combined with Gemcitabine and Oxaliplatin (Gemox) for the treatment of middle and advanced pancreatic cancer in elderly patients.

Methods

Forty-seven patients with pancreatic cancer treated with HIFU and Gemox were evaluated for inclusion, and 38 cases were finally included. The primary endpoint was safety. Secondary endpoints included the response rate, the clinical benefit response (CBR), overall survival (OS), progression-free survival (PFS).

Results

After combination therapy of HIFU and Gemox, severe complications were rarely reported, and no treatment-related death occurred. The rate of three or four-degree myelosuppression was low, and no obvious impairment of hepatorenal function was observed. Pancreatitis and gastrointestinal injury did not occurred. The disease control rate (DCR) was estimated to be 76.3%, including complete remission (CR), partial remission (PR), stable disease (SD) in 1, 6, 22 cases, respectively. And the objective response rate (ORR) was 18.4%. The clinical benefit rate (CBR) was 68.4%, with the pain significantly relieved (P<0.01). The serum level of CA19-9 showed significant changes after HIFU treatment. The median overall survival (OS) was 12.5 months, with a 6-month and 12-month OS rate of 82.13% and 59.34%, respectively. Stratified analyses did not reveal any significant difference between patients in different stages.

Conclusion

Elderly patients (≥ 60 years old) with pancreatic cancer would experience tolerable toxicity and obtain good clinical benefits from the combination therapy of HIFU ablation and Gemox.

Role of the novel gene BZW2 in the development of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in adults. Basic leucine zipper and W2 domains 2 (BZW2) is a member of the basic-region leucine zipper (bZIP) superfamily of transcription factors. Here, we found that BZW2 expression was substantially increased in both human HCC tissues and cell lines, which was correlated with the clinical progression of patients with HCC. Silence of BZW2 in HCC cells by infecting with the lentivirus for delivering BZW2 shRNA (short hairpin RNA), prohibits cell progression, as determined by the suppressed cell proliferation, clonality, invasion, and increased cell apoptosis. Furthermore, overexpression of BZW2 promotes drug resistance of HCC cells, as shown by the attenuated suppression of cell viability and invasion following rapamycin (RAPA) treatment. Mechanistically, overexpression (or silence) of BZW2 in HCC cells significantly stimulates (or decreases) the activation of the PI3K/AKT/mTOR signaling pathway, which is responsible for HCC progression. Thus, increased BZW2 expression in HCC can induce HCC progression and drug resistance via stimulating the PI3K/AKT/mTOR pathway, which may represent a new therapeutic target for HCC.

Acoustic radiation force imaging using a single-shot spiral readout

The purpose of this study is to develop and validate rapid magnetic resonance acoustic radiation force imaging (MR-ARFI) using a single shot spiral readout for focused ultrasound (FUS) guidance and for local tissue displacement measurements. A magnetic resonance guided FUS system was used to focus a 3 MHz ultrasound beam to a predetermined position. MR-ARFI was performed with a Bruker 7 T MRI using a modified single-shot spiral readout, with additional motion encoding gradients that convert local displacement into the phase image. Post processing was then used to analyze the resulting displacement and to evaluate the method's performance for the detection of tissue changes resulting from thermal ablation. The single-shot spiral readout acquires a single MR-ARFI image in one second, which is up to two orders of magnitude faster than conventional 2D spin-warp spin echo that acquires the k-space data line by line. The ARFI displacement in tissue mimicking phantoms was detected and localized with less than 5% geometric distortion. The ARFI displacement was also measured pre and post thermal ablation in an ex vivo chicken breast. For transmitted peak negative pressure of 8.6 MPa, the maximum displacement of the tissue that was ablated to 70 °C was 78% lower than the pre-ablated tissue. Since spiral readout is not prone to geometrical distortion, it is well-suited for FUS guidance, without generating undesired temperature elevation. Additionally, local displacement measurements of tissues can be performed rapidly during thermal ablation procedures and may help to assess the success of the treatment.

High-intensity focused ultrasound enhances the effect of bufalin by inducing apoptosis in pancreatic cancer cells

Purpose

High-intensity focused ultrasound (HIFU) has the potential to be an effective therapeutic strategy for pancreatic cancer (PC). However, owing to the high malignancy and poor prognosis of PC, the use of HIFU therapy alone is not sufficient to impair the progression of PC. Bufalin, a compound extracted from traditional medicine, is known to inhibit the growth and progression of PC cells. However, the effect of the combination therapy of HIFU plus bufalin (HIFU+bufalin) is still uncertain.

Materials and methods

A colony formation assay and flow cytometry were performed to measure the growth and induction of apoptosis in PC cells. Western blotting was used to explore the potential mechanism of HIFU and bufalin therapy. The in vivo efficacy of HIFU+bufalin was tested in a MiaPaCa₂ xenograft model.

Results

Bufalin inhibited the growth of PC cells more obviously compared to HIFU. Combining bufalin with HIFU further decreased the growth of MiaPaCa₂ cells compared with single therapy in vitro. Flow cytometry results showed that the percentage of surviving MiaPaCa₂ cells in the bufalin-treated group and the HIFU-treated group was approximately three-fold and two-fold higher than in the HIFU+bufalin-treated group. Contrasting results were found in Panc-1 cells. Biochemical analysis revealed that HIFU+bufalin treatment elevated PARP expression and increased caspase-8 activation in MiaPaCa₂ and Panc-1 cells. HIFU+bufalin significantly reduced the growth of MiaPaCa₂ tumors compared with HIFU or bufalin treatment alone. HIFU+bufalin treatment decreased Ki67 staining and increased activated caspase-3 and caspase 8 staining, when compared with HIFU or bufalin treatment alone in mouse tumors.

Conclusion

HIFU enhanced the effect of bufailn by inducing apoptosis in PC cells. A combination of HIFU and bufalin may be employed as an alternative therapeutic strategy for PC.

Thermal ablation of pancreatic cancer: A systematic literature review of clinical practice and pre-clinical studies

PURPOSE

Pancreatic cancer is a challenging malignancy with low treatment option and poor life expectancy. Thermal ablation techniques were proposed as alternative treatment options, especially in advanced stages and for unfit-for-surgery patients. This systematic review describes the thermal ablative techniques -i.e., Laser (LA), Radiofrequency (RFA), Microwave (MWA) Ablation, High-Intensity Focused Ultrasound (HIFU) and cryoablation- available for pancreatic cancer treatment. Additionally, an analysis of the efficacy, complication rate and overall survival for each technique is conducted.

MATERIAL AND METHODS

This review collects the ex vivo, preclinical and clinical studies presenting the use of thermal techniques in the pancreatic cancer treatment, searched up to March 2018 in PubMed and Medline. Abstracts, letters-to-the-editor, expert opinions, reviews and non-English language manuscripts were excluded.

RESULTS

Sixty-five papers were included. For the ex vivo and preclinical studies, there are: 12 records for LA, 8 for RFA, 0 for MWA, 6 for HIFU, 1 for cryoablation and 3 for hybrid techniques. For clinical studies, 1 paper for LA, 14 for RFA, 1 for MWA, 17 for HIFU, 1 for cryoablation and 1 for hybrid techniques.

CONCLUSIONS

Important technological advances are presented in ex vivo and preclinical studies, as the real-time thermometry, nanotechnology and hybrid techniques to enhance the thermal outcome. Conversely, a lack of standardization in the clinical employment of the procedures emerged, leading to contrasting results on the safety and feasibility of some analyzed techniques. Uniform conclusions on the safety and feasibility of these techniques for pancreatic cancer will require further structured investigation.

Response of patients with locally advanced pancreatic adenocarcinoma to high-intensity focused ultrasound treatment: a single-center, prospective, case series in China

Purpose

Patients with unresectable locally advanced pancreatic cancer (LAPC) are still in dire need of effective therapies. We performed this cohort study in order to assess the efficacy and safety of high-intensity focused ultrasound (HIFU) ablation in treating patients with unresectable LAPC.

Patients and methods

Eighty-seven cases with unresectable LAPC from January 2014 to December 2016 were finally recruited according to the inclusion criteria. The primary end point of our study was OS of all the cases, and the secondary end points included 6-month and 12-month survival rate, tumor response rate, carbohydrate antigen (CA) 19-9 response rate, VAS, quality of life, and safety.

Results

All the 87 patients received HIFU ablation successfully, and were included in the efficacy and safety analysis. With a median follow-up of 16 months, median OS was estimated to be 12.2 months, with 95 % CI of 11.1–12.7 months. The 6-month and 12-month survival rates were 94.25% (95% CI =86.74–97.57) and 50.85% (95% CI =38.17–62.21), respectively. Multivariate analysis revealed that patients with VAS <4, Karnofsky performance status ≥80, and tumor size <3 cm have a significant improvement in their OS (adjusted HR [aHR] =0.26 [95% CI =0.12–0.57], P=0.001; aHR =0.34 [95% CI =0.17–0.68], P=0.02; and aHR =0.39 [95% CI =0.20–0.78], P=0.007; respectively). Tumor responses were observed in 32 (36.8%) of 87 patients and CA 19-9 response rate was 56.2%. Global health status, physical function, emotional function, and cognitive function of patients were significantly improved after HIFU treatment, and symptoms of fatigue and pain were significantly reduced. A total of 28.7% (25/87) of patients reported adverse events (AEs), mainly including fatigue (14/87), abdominal pain (7/87), fever (7/87), nausea (5/87), and rash (4/87). No severe AEs and HIFU-related deaths were reported.

Conclusion

HIFU ablation might be a potentially effective and safe therapeutic option for the patients with unresectable LAPC.

A portable high-intensity focused ultrasound system for the pancreas with 3D electronic steering: a preclinical study in a swine model

PURPOSE

The aim of this animal study was to evaluate the safety and feasibility of a portable, ultrasonography-guided, high-intensity focused ultrasound (USg-HIFU) system to treat the pancreas.

METHODS

Eight swine were included. Using a portable HIFU device (ALPIUS 900, Alpinion Medical Systems), ablations were performed on the pancreas in vivo. Different acoustic intensities were applied (1.7 kW/cm2 or 1.5 kW/cm2 , n=2 [group A for a pilot study]; 1.5 kW/ cm2 , n=3 [group B]; and 1.2 kW/cm2 , n=3 [group C]). Magnetic resonance imaging (MRI) was performed immediately (group A) or 7 days (groups B and C) after HIFU treatment. In groups B and C, serum amylase and lipase levels were measured on days 0 and 7, and performance status was observed every day. Necropsy was performed on days 0 (group A) or 7 (groups B and C) to assess the presence of unintended injuries and to obtain pancreatic and peripancreatic tissue for histological analysis.

RESULTS

Ablation was noted in the pancreas in all swine on MRI, and all pathologic specimens showed coagulation necrosis in the treated area. The mean ablation areas on MRI were 85.3±38.1 mm2, 90.7±21.2 mm2, and 54.4±30.6 mm2 in groups A, B, and C, respectively (P>0.05). No animals showed evidence of complications, except for one case of a pseudocyst in group B.

CONCLUSION

This study showed that pancreas ablation using a portable USg-HIFU system may be safe and feasible, and that coagulation necrosis of the pancreas was successfully achieved with a range of acoustic intensities.

[High-intensity focused ultrasound (HIFU) for tumor pain relief in inoperable pancreatic cancer : Evaluation with the pain sensation scale (SES)]

BACKGROUND

High-intensity focused ultrasound (HIFU) in combination with palliative standard therapy is an innovative and effective treatment option for pain reduction in patients with inoperable pancreatic cancer.

OBJECTIVE

Evaluation of the effects of additive ultrasound (US)-guided HIFU treatment in inoperable pancreatic cancer on the sensory and affective pain perception using validated questionnaries.

MATERIAL AND METHODS

In this study 20 patients with locally advanced inoperable pancreatic cancer and tumor-related pain were treated by US-guided HIFU (6 stage III, 12 stage IV according to UICC and 2 with local recurrence after surgery). Ablation was performed using the JC HIFU system (HAIFU, Chongqing, China) with an ultrasonic device for real-time imaging. Clinical assessment included evaluation of pain severity using validated questionnaires with particular attention to the pain sensation scale (SES) with its affective and sensory component and the numeric rating scale (NRS).

RESULTS

The average pain reduction after HIFU was 2.87 points on the NRS scale and 57.3 % compared to the mean baseline score (n = 15, 75 %) in 19 of 20 treated patients. Four patients did not report pain relief, however, the previous opioid medication could be stopped (n = 2) or the analgesic dosage could be reduced (n = 2). No pain reduction was achieved in one patient. Furthermore, after HIFU emotional as well as sensory pain aspects were significantly reduced (before vs. 1 week after HIFU, p < 0.05 for all pain scales).

CONCLUSION

US-guided HIFU can be used for effective and early pain relief and reduction of emotional and sensory pain sensation in patients with locally advanced pancreatic cancer.

Focused ultrasound for immuno-adjuvant treatment of pancreatic cancer: An emerging clinical paradigm in the era of personalized oncotherapy

Current clinical treatment regimens, including many emergent immune strategies (e.g., checkpoint inhibitors) have done little to affect the devastating course of pancreatic ductal adenocarcinoma (PDA). Clinical trials for PDA often employ multi-modal treatment, and have started to incorporate stromal-targeted therapies, which have shown promising results in early reports. Focused ultrasound (FUS) is one such therapy that is uniquely equipped to address local and systemic limitations of conventional cancer therapies as well as emergent immune therapies for PDA. FUS methods can non-invasively generate mechanical and/or thermal effects that capitalize on the unique oncogenomic/proteomic signature of a tumor. Potential benefits of FUS therapy for PDA include: (1) emulsification of targeted tumor into undenatured antigens in situ, increasing dendritic cell maturation, and increasing intra-tumoral CD8+/ T regulatory cell ratio and CD8+ T cell activity; (2) reduction in intra-tumoral hypoxic stress; (3) modulation of tumor cell membrane protein localization to enhance immunogenicity; (4) modulation of the local cytokine milieu toward a Th1-type inflammatory profile; (5) up-regulation of local chemoattractants; (6) remodeling the tumor stroma; (7) localized delivery of exogenously packaged immune-stimulating antigens, genes and therapeutic drugs. While not all of these results have been studied in experimental PDA models to date, the principles garnered from other solid tumor and disease models have direct relevance to the design of optimal FUS protocols for PDA. In this review, we address the pertinent limitations in current and emergent immune therapies that can be improved with FUS therapy for PDA.

A meta-analysis of palliative treatment of pancreatic cancer with high intensity focused ultrasound

BACKGROUND

Pancreatic adenocarcinoma is currently the fourth-leading cause of cancer-related death. Up to 60-90% of patients with advanced disease suffer cancer-related pain, severely impacting their quality of life. Current management involves primarily pharmacotherapy with opioid narcotics and celiac plexus neurolysis; unfortunately, both approaches offer transient relief and cause undesired side-effects. High intensity focused ultrasound (HIFU) is a non-invasive thermal ablation technique that has been used to treat pancreatic cancer. This meta-analysis aims to evaluate the role of HIFU in pain palliation of advanced unresectable pancreatic adenocarcinoma.

METHODS

An electronic search was performed in PubMed Medline database up to the end of July 2016, for unresectable pancreatic cancer pain palliation with HIFU. Pertinent studies were identified through the PubMed search engine using the following keywords: HIFU, pancreas, pancreatic cancer, pain and palliation. Additional studies were included after manual search of the selected bibliographies. Pain palliation results reported in each study were analyzed using a logit-transformed random-effects model using the inverse variance method, with the DerSimonian-Laird estimator for τ2, and Cochran's Q test for heterogeneity among studies. The I2 was calculated to assess the percentage of the total variability in the different effect size estimates that can be attributed to heterogeneity among the true effects. A rank correlation test of funnel plot asymmetry was done to assess possible publication bias.

RESULTS

The meta-analysis includes a total number of 23 studies with 865 patients, 729 with pancreatic cancer. The population enrolled ranges from 3 patients in the smallest series, up to 61 in the largest study. τ2 (variance among studies) was 0.195, and I2 (percentage of variation among studies) was 40% (95% CI: 1-64%); the Q test p-value was 0.026, indicating significant heterogeneity among studies. Among 639 patients treated with HIFU, 567 complained of pancreatic pain before the treatment and 459 patients experienced partial or complete pain relief after treatment. The random effects estimate of the proportion of patients with pain reduction was 0.81 (95% CI: 0.76-86).

CONCLUSIONS

HIFU appears to be an effective tool for pain palliation in advanced pancreatic cancer. Studies assessing treatment in patients with pancreatic adenocarcinoma are limited by factors such as small sample sizes and heterogeneity in clinical definitions and assessments. Prospective randomized and standardized studies are necessary to confirm the effectiveness of HIFU in relieving pain, and to evaluate for any potential impact on tumor control and patient survival.

Therapeutic Effects of Microbubbles Added to Combined High-Intensity Focused Ultrasound and Chemotherapy in a Pancreatic Cancer Xenograft Model

Objective

To investigate whether high-intensity focused ultrasound (HIFU) combined with microbubbles enhances the therapeutic effects of chemotherapy.

Materials and Methods

A pancreatic cancer xenograft model was established using BALB/c nude mice and luciferase-expressing human pancreatic cancer cells. Mice were randomly assigned to five groups according to treatment: control (n = 10), gemcitabine alone (GEM; n = 12), HIFU with microbubbles (HIFU + MB, n = 11), combined HIFU and gemcitabine (HIGEM; n = 12), and HIGEM + MB (n = 13). After three weekly treatments, apoptosis rates were evaluated using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay in two mice per group. Tumor volume and bioluminescence were monitored using high-resolution 3D ultrasound imaging and in vivo bioluminescence imaging for eight weeks in the remaining mice.

Results

The HIGEM + MB group showed significantly higher apoptosis rates than the other groups (p < 0.05) and exhibited the slowest tumor growth. From week 5, the tumor-volume-ratio relative to the baseline tumor volume was significantly lower in the HIGEM + MB group than in the control, GEM, and HIFU + MB groups (p < 0.05). Despite visible distinction, the HIGEM and HIGEM + MB groups showed no significant differences.

Conclusion

High-intensity focused ultrasound combined with microbubbles enhances the therapeutic effects of gemcitabine chemotherapy in a pancreatic cancer xenograft model.

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.

High-intensity focused ultrasound (HIFU) for pancreatic carcinoma: evaluation of feasibility, reduction of tumour volume and pain intensity

OBJECTIVES

Prognosis of patients with locally advanced pancreatic adenocarcinoma is extremely poor. They often suffer from cancer-related pain reducing their quality of life. This prospective observational study aimed to evaluate feasibility, local tumour response, and changes in quality of life and symptoms in Caucasian patients with locally advanced pancreatic cancer treated by ultrasound-guided high-intensity focused ultrasound (HIFU).

METHODS

Thirteen patients underwent HIFU, five with stage III, eight with stage IV UICC disease. Ten patients received simultaneous palliative chemotherapy. Postinterventional clinical assessment included evaluation of quality of life and symptom changes using standardized questionnaires. CT and MRI follow-up evaluated the local tumour response.

RESULTS

HIFU was successfully performed in all patients. Average tumour reduction was 34.2 % at 6 weeks and 63.9 % at 3 months. Complete or partial relief of cancer-related pain was achieved in 10 patients (77 %), five of whom required less analgesics for pain control. Quality of life was improved revealing increased global health status and alleviated symptoms. HIFU treatment was well tolerated. Eight patients experienced transient abdominal pain directly after HIFU.

CONCLUSIONS

HIFU ablation of pancreatic carcinoma is a feasible, safe and effective treatment with a crucial benefit in terms of reduction of tumour volume and pain intensity.

KEY POINTS

• US-guided HIFU is feasible and safe for patients with unresectable pancreatic cancer. • HIFU can considerably reduce tumour volume and cancer-related pain. • Patients treated with HIFU experienced significant and lasting reduction of pain intensity. • HIFU has a crucial clinical benefit for patients with pancreatic cancer.

Pancreatic Solid and Cystic Neoplasms: Diagnostic Evaluation and Intervention

High-resolution imaging modalities, such as multi-detector computed tomography, MR imaging, and endoscopic ultrasound, are frequently used alone or in combination to characterize focal solid and cystic pancreatic neoplasms. Imaging in solid pancreatic neoplasms, typically adenocarcinoma and neuroendocrine tumors, is primarily used to detect and stage the extent of the tumor and to determine if complete surgical resection for cure is feasible. In cystic pancreatic masses, imaging aims to differentiate benign nonmucinous cystic lesions from potentially or frankly malignant mucin-producing cysts. Several noninvasive and invasive treatment options can be performed if surgical resection is not possible or contraindicated.

The use of high-intensity focused ultrasound as a novel treatment for painful conditions-a description and narrative review of the literature

High-intensity focused ultrasound (HIFU) is a non-invasive technique that allows a small, well-circumscribed thermal lesion to be generated within a tissue target. Tissue destruction occurs due to direct heating within the lesion and the mechanical effects of acoustic cavitation. HIFU has been used in a broad range of clinical applications, including the treatment of malignancies, uterine fibroids and cardiac arrhythmias. Interest in the use of the technique to treat pain has recently increased. A number of painful conditions have been successfully treated, including musculoskeletal degeneration, bone metastases and neuropathic pain. The exact mechanism by which HIFU results in analgesia remains poorly understood, but it is thought to be due to localised denervation of tissue targets and/or neuromodulatory effects. The majority of studies conducted investigating the use of HIFU in pain are still at an early stage, although initial results are encouraging. Further research is indicated to improve our understanding of the mechanisms underlying this treatment and to fully establish its efficacy; however, it is likely that HIFU will play a role in pain management in the future. This narrative review provides a synthesis of the recent, salient clinical and basic science research related to this topic and gives a general introduction to the mechanisms by which HIFU exerts its effects.

An MRI-conditional motion phantom for the evaluation of high-intensity focused ultrasound protocols

BACKGROUND

The respiratory motion of abdominal organs is a serious obstacle in high-intensity focused ultrasound (HIFU) treatment with magnetic resonance imaging (MRI) guidance. In this study, a two-dimensional (2D) MRI-conditional motion phantom device was developed in order to evaluate HIFU protocols in synchronized and non-synchronized ablation of moving targets.

MATERIALS AND METHODS

The 2D phantom device simulates the respiratory motion of moving organs in both the left-right and craniocaudal directions. The device consists of MR-conditional materials which have been produced by a three-dimensional (3D) printer.

RESULTS

The MRI compatibility of the motion phantom was tested successfully in an MRI scanner. In vitro experiments were carried out to evaluate HIFU ablation protocols that are minimally affected by target motion.

CONCLUSION

It was shown that only in synchronized mode does HIFU produce thermal lesions, as tested on a gel phantom mimicking the moving target. The MRI-conditional phantom device was shown to be functional for its purpose and can be used as an evaluation tool for testing HIFU protocols for moving targets in an MRI environment. Copyright © 2015 John Wiley & Sons, Ltd.

Generation and Quantitative Analysis of Pulsed Low Frequency Ultrasound to Determine the Sonic Sensitivity of Untreated and Treated Neoplastic Cells

Low frequency ultrasound in the 20 to 60 kHz range is a novel physical modality by which to induce selective cell lysis and death in neoplastic cells. In addition, this method can be used in combination with specialized agents known as sonosensitizers to increase the extent of preferential damage exerted by ultrasound against neoplastic cells, an approach referred to as sonodynamic therapy (SDT). The methodology for generating and applying low frequency ultrasound in a preclinical in vitro setting is presented to demonstrate that reproducible cell destruction can be attained in order to examine and compare the effects of sonication on neoplastic and normal cells. This offers a means by which to reliably sonicate neoplastic cells at a level of consistency required for preclinical therapeutic assessment. In addition, the effects of cholesterol-depleting and cytoskeletal-directed agents on potentiating ultrasonic sensitivity in neoplastic cells are discussed in order to elaborate on mechanisms of action conducive to sonochemotherapeutic approaches.

3D perfused brain phantom for interstitial ultrasound thermal therapy and imaging: design, construction and characterization

Thermal therapy has emerged as an independent modality of treating some tumors. In many clinics the hyperthermia, one of the thermal therapy modalities, has been used adjuvant to radio- or chemotherapy to substantially improve the clinical treatment outcomes. In this work, a methodology for building a realistic brain phantom for interstitial ultrasound low dose-rate thermal therapy of the brain is proposed. A 3D brain phantom made of the tissue mimicking material (TMM) had the acoustic and thermal properties in the 20-32 °C range, which is similar to that of a brain at 37 °C. The phantom had 10-11% by mass of bovine gelatin powder dissolved in ethylene glycol. The TMM sonicated at 1 MHz, 1.6 MHz and 2.5 MHz yielded the amplitude attenuation coefficients of 62  ±  1 dB m(-1), 115  ±  4 dB m(-1) and 175  ±  9 dB m(-1), respectively. The density and acoustic speed determination at room temperature (~24 °C) gave 1040  ±  40 kg m(-3) and 1545  ±  44 m s(-1), respectively. The average thermal conductivity was 0.532 W m(-1) K(-1). The T1 and T2 values of the TMM were 207  ±  4 and 36.2  ±  0.4 ms, respectively. We envisage the use of our phantom for treatment planning and for quality assurance in MRI based temperature determination. Our phantom preparation methodology may be readily extended to other thermal therapy technologies.

High intensity focused ultrasound: A noninvasive therapy for locally advanced pancreatic cancer

The noninvasive ablation of pancreatic cancer with high intensity focused ultrasound (HIFU) energy is received increasingly widespread interest. With rapidly temperature rise to cytotoxic levels within the focal volume of ultrasound beams, HIFU can selectively ablate a targeted lesion of the pancreas without any damage to surrounding or overlying tissues. Preliminary studies suggest that this approach is technical safe and feasible, and can be used alone or in combination with systemic chemotherapy for the treatment of patients with locally advanced pancreatic cancer. It can effectively alleviate cancer-related abdominal pain, and may confer an additional survival benefit with few significant complications. This review provides a brief overview of HIFU, describes current clinical applications, summarizes characteristics of continuous and pulsed HIFU, and discusses future applications and challenges in the treatment of pancreatic cancer.

Emerging HIFU applications in cancer therapy

High intensity focused ultrasound (HIFU), is a promising, non-invasive modality for treatment of tumours in conjunction with magnetic resonance imaging or diagnostic ultrasound guidance. HIFU is being used increasingly for treatment of prostate cancer and uterine fibroids. Over the last 10 years a growing number of clinical trials have examined HIFU treatment of both benign and malignant tumours of the liver, breast, pancreas, bone, connective tissue, thyroid, parathyroid, kidney and brain. For some of these emerging indications, HIFU is poised to become a serious alternative or adjunct to current standard treatments--including surgery, radiation, gene therapy, immunotherapy, and chemotherapy. Current commercially available HIFU devices are marketed for their thermal ablation applications. In the future, lower energy treatments may play a significant role in mediating targeted drug and gene delivery for cancer treatment. In this article we introduce currently available HIFU systems, provide an overview of clinical trials in emerging oncological targets, and briefly discuss selected pre-clinical research that is relevant to future oncological HIFU applications.

High-intensity focused ultrasound treatment for advanced pancreatic cancer

Pancreatic cancer is under high mortality but has few effective treatment modalities. High-intensity focused ultrasound (HIFU) is becoming an emerging approach of noninvasively ablating solid tumor in clinics. A variety of solid tumors have been tried on thousands of patients in the last fifteen years with great success. The principle, mechanism, and clinical outcome of HIFU were introduced first. All 3022 clinical cases of HIFU treatment for the advanced pancreatic cancer alone or in combination with chemotherapy or radiotherapy in 241 published papers were reviewed and summarized for its efficacy, pain relief, clinical benefit rate, survival, Karnofsky performance scale (KPS) score, changes in tumor size, occurrence of echogenicity, serum level, diagnostic assessment of outcome, and associated complications. Immune response induced by HIFU ablation may become an effective way of cancer treatment. Comments for a better outcome and current challenges of HIFU technology are also covered.

Real-time monitoring of HIFU treatment using pulse inversion

Ultrasound (US) imaging is widely used for the real-time guidance of high-intensity focused ultrasound (HIFU) treatment at a relatively low cost. However, ultrasound image guided HIFU (USgHIFU) is limited in the real-time monitoring of HIFU treatment due to the large amplitude HIFU signals received by the US imaging transducer. The amplitude of the HIFU scattered signal is generally much higher than the amplitude of the pulse-echo signal received by the imaging transducer. This creates an interference pattern obscuring the image of the tissue. As such, it is difficult to monitor lesion location. This paper proposes a real-time monitoring method to be performed concurrently with the HIFU insonation, but without HIFU interference, which allows for the improvement of treatment accuracy and safety in USgHIFU. The proposed method utilizes the physical properties of pulse inversion which is capable of removing the fundamental and odd harmonic components of the HIFU interference. Therefore, it is possible to secure the desired spectral bandwidth used to construct US images for HIFU treatment monitoring. The performance of the proposed method was evaluated through experiments with both a bovine serum albumin phantom and a chicken breast. The results demonstrated that the proposed method is capable of providing interference-free US images, thus successfully allowing for US imaging during HIFU treatment.