Radiofrequency ablation of unresectable primary and metastatic hepatic malignancies: results in 123 patients

Endoscopic loco-regional treatment in controlling pancreatic neuroendocrine tumors (PNETs) behavior: a case series and literature review

Pancreatic neuroendocrine tumors (PNETs) are considered rare pancreatic neoplasms, and it is a challenging disease entity due to its indolent behavior and is difficult to manage. Diagnostic challenge is usually found in the imaging-based approach, such as transabdominal ultrasound, abdominal CT scan, and abdominal MRI. Surgery is still the main key player in controlling the disease. The main problems in clinical practice are the early detection of small PNETs lesion and non-functional PNET (NF-PNET) cases. Most cases usually come with large tumor size or metastatic disease. Endoscopic ultrasound (EUS) has been well-known as the most sensitive tool for early detection of pancreatic malignancy. It has now also been developed for managing pancreatic cancer, such as tumor ablation therapy. We presented four variety of PNETs cases (one patient with non-functioning PNETs and three patients with functioning PNETs) who have been successfully treated with EUS-guided radiofrequency ablation (RFA) with good control of tumor growth during follow-up. One patient with a large-size insulinoma could have the tumor controlled gradually after several EUS-RFA sessions. No adverse events or major complications were observed during and after the EUS-RFA procedure. EUS has been shown as a promising tool not only for more accurate diagnosis but also for tumor growth control. However, it would need further comparison studies between EUS and surgical approaches to make a better treatment strategy.

Overexpression of PLK1 Molecule Following Incomplete Thermal Ablation Promotes the Proliferation and Invasion of Residual Hepatocellular Carcinoma

TAT, a widely used treatment for HCC, can exacerbate the progression of residual HCC. The present study investigated the mechanism of action of PLK1 following ITA of HCC. The PLK1 levels in HCC were determined using qRT-PCR from clinical patient samples, IHC from tissue microarray, and data from globally high-throughput data and microarrays. The PLK1 levels and their effect on the biological phenotype of heat-stress HCC cells were evaluated through in vitro experiments. We detected PLK1 abnormal expression in HCC models of nude mice subjected to ITA. We detected the effects of different PLK1 expression levels on EMT pathway proteins. PLK1 exhibited an overexpression in HCC tissues with an SMD of 1.19 (3414 HCC and 3036 non-HCC tissues were included), distinguishing HCC from non-HCC effectively (AUC = 0.9). The qRT-PCR data from clinical HCC patient samples and IHC from HCC tissue microarray results also indicated an overexpressed level. In the incomplete ablation models, an increased PLK1 expression was found in both heat-stress cells and subcutaneous tumors. The upregulation of PLK1 following ITA was found to enhance the malignancy of HCC and exacerbate the proliferation, migration, and invasion of residual HCC cells, whereas PLK1 knockdown suppressed the biological malignancy of HCC cells. Meanwhile, PLK1 has different regulatory effects on various EMT pathway proteins. PLK1 promotes the progression of residual HCC by activating EMT pathway after ITA, which might provide a novel idea for the treatment and prognosis of residual HCC.

Treatment of Warthin's Tumors of the Parotid Gland With Radiofrequency Ablation: A Systematic Review of the Current Literature

Objective: Warthin's tumors of the parotid gland can be safely observed. Definitive treatment usually requires parotidectomy under general anesthesia. The decision to operate on Warthin's tumors of the parotid gland can be complicated in patients who wish to avoid risks of surgery and general anesthesia. This systematic review explores the potential of radiofrequency ablation (RFA) as a minimally invasive alternative. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) model was used to collect 3 relevant studies that focused on RFA treatment for Warthin's tumors. The cumulative averages for tumor size and cosmetic scores were then quantified for patients with Warthin's tumors who underwent RFA therapy. The PRISMA systematic review method was employed to the PubMed and EMBASE databases. The comprehensive search term "Warthin Tumor Treatment" yielded 1299 articles from the years 1955 to 2023, 3 of which met inclusion criteria and were then selected. Results: The 3 quantitative studies collectively assessed 37 patients with Warthin's tumors treated with RFA. Patients experienced an average tumor size reduction of 85.03% at 12 months post-RFA. There were minimal complications associated with RFA in these patients. Conclusion: This study suggests that RFA is an alternative to parotidectomy for the symptomatic treatment of Warthin's tumors. RFA procedures demonstrated substantial tumor size reduction with few complications. However, further meta-analysis and comparison with alternative treatments is warranted to establish RFA's role in treatment of Warthin's tumors. The study is limited by its reliance on only 2 databases and a lack of comprehensive examination of different RFA settings.

Intraoperative radiofrequency ablation for unresectable abdominal paraganglioma: a case report

For pheochromocytoma and paraganglioma (PPGL), the efficacy of percutaneous ablative therapies in achieving control of metastatic tumors measuring <3 cm had been demonstrated in only few reports, and intraoperative radiofrequency ablation (RFA) of locally invasive primary PPGLs has not been reported. We presented the case of a 31-year-old man who had a 9-cm functioning unresectable PPGL. He was treated with 13 cycles of cytotoxic chemotherapy without objective tumor response, according to the Response Evaluation Criteria in Solid Tumors (RECIST). Subsequently, magnetic resonance imaging revealed a 9.0 × 8.6 × 6.0-cm retroperitoneal mass that extended to the inferior portion of the inferior vena cava, the inferior mesenteric artery, and the infrarenal aorta. Biochemical evaluation demonstrated high level of plasma normetanephrine (20.2 nmol/L, normal range <0.9 nmol/L). Genetic investigation showed the germline pathogenic variant c.1591delC (p. Ser198Alafs*22) in the SDHB gene. I131-metaiodobenzylguanidine scintigraphy was negative and Ga68-dotatate PET-CT scan showed high tumor uptake without distant metastases. On open laparotomy, tumor debulking was not possible. Therefore, intraoperative RFA was performed by a highly experienced team of interventional radiologists. At 12 months after the RFA, the tumor volume decreased from 208 to 45 mL (78%), plasma normetanephrine decreased from 20.2 to 2.6 nmol/L (87%), and the doxazosin dose was reduced from 16 to 8 mg/day. To our best knowledge, this was the first report on intraoperative RFA that markedly reduced the size of a large primary unresectable PPGL, along with clinical and biochemical responses.

Single-fiber probes for combined sensing and imaging in biological tissue: recent developments and prospects

Single-fiber-based sensing and imaging probes enable the co-located and simultaneous observation and measurement (i.e., 'sense' and 'see') of intricate biological processes within deep anatomical structures. This innovation opens new opportunities for investigating complex physiological phenomena and potentially allows more accurate diagnosis and monitoring of disease. This prospective review starts with presenting recent studies of single-fiber-based probes for concurrent and co-located fluorescence-based sensing and imaging. Notwithstanding the successful initial demonstration of integrated sensing and imaging within single-fiber-based miniaturized devices, the realization of these devices with enhanced sensing sensitivity and imaging resolution poses notable challenges. These challenges, in turn, present opportunities for future research, including the design and fabrication of complex lens systems and fiber architectures, the integration of novel materials and other sensing and imaging techniques.

Efficacy and safety of radiofrequency ablation in the treatment of inoperable patients with pulmonary malignant nodules

BACKGROUND

Radiofrequency ablation (RFA) has been recently applied as an alternative treatment in the patients with pulmonary malignancies. The aim of our study was to assess the incidence of complications and survival rate of RFA for malignant lung nodules, and evaluate the efficacy and safety of RFA in the treatment of inoperable patients with pulmonary malignant nodules.

METHODS

The clinical data of 50 patients with primary and metastatic lung malignant nodules treated with RFA from June 2015 and July 2017 in Hebei General Hospital were considered, and the characteristics and clinical data of these patients were analysed. Complications, progression-free survival and overall survival at 1, 2 and 5 years of these patients were evaluated.

RESULTS

Following the procedure. There were no major complications and deaths during the operation. 26 (52%) patients presented mild-to-moderate chest pain that was easily controlled by analgesic drugs. 8 (16%) patients with pneumothorax, 4 (8%) haemoptysis, 6 (12%) pneumonia, 7 (14%) pleural effusion and 1 (2%) postoperative bronchopleural fistula. Needle-track implantation was observed in 2 (4%) patients. Median progression-free survival (PFS) was 24.6 months. The PFS at 1, 2, 5 years was 76%, 52% and 20%, respectively. Median overall survival (OS) was 35.5 months. The OS at 1, 2 and 5 years was 80%, 58% and 32%, respectively.

CONCLUSION

RFA is a safe and effective alternative treatment for the inoperable patients with primary or metastatic pulmonary malignant nodules. The clinical impact and long-term results of RFA need to be further confirmed in a larger series of patients, and RFA should ideally be compared with surgery.

Percutaneous ablative therapies for hepatocellular carcinoma in the caudate lobe of the liver: efficacy and outcome

OBJECTIVE

To assess the efficacy and outcomes of percutaneous ablative therapies for hepatocellular carcinoma (HCC) in the caudate lobe.

METHODS

Patients within Milan criteria, who underwent thermal ablation (RFA/MWA) for HCC were analyzed. Based on the inclusion-criteria, patients were categorized in two groups. Group-1 (caudate-lobe HCC) and Group-2 (non-caudate-lobe HCC). Both the groups were analyzed for technical success (TS), local tumor progression (LTP), disease-free survival (DFS), and overall survival (OS) were compared between both the groups. Predictive factors for LTP, DFS, or OS in the study cohort were analyzed using appropriate statistical analyses.

RESULTS

Twenty-one patients qualified to be in Group-1 while 130 patients fulfilled the criteria for Group-2. TS of 90.5 and 97.7% was seen after the first session of ablation for Group-1 and group-2 respectively, while a TS of 95.2% (Group-1) and 100% (Group-2) was achieved after second session. The right-intercostal-approach was used in 66.7% (n = 14) and the anterior-epigastric-approach was used in 33.3% (n = 7) of patients having caudate-lobe HCC. Procedure-related complications in both the groups were comparable. Although, statistically insignificant, LTP in the Group-1 (19.5%, n = 4) was twice that of non-caudate lobe HCC (8.5%, n = 11). The cumulative DFS rate was better in Group-2 while OS in both groups were comparable. Multivariate analysis showed: tumor size and ablative margin of 5 mm being independent predictors of LTP after percutaneous-ablation of caudate-lobe HCC.

CONCLUSION

Ablative therapies for HCC in caudate lobe is feasible and safe with comparable LTP and OS to non-caudate lobe HCC. Tumor size >2 cm and lack of 5 mm ablative margin are independent predictors of LTP.

ADVANCES IN KNOWLEDGE

1. Percutaneous ablation of caudate lobe HCC is feasible using anterior epigastric approach or right intercostal approach. 2. These approaches may allow a safe and effective ablation of caudate lobe HCC with results comparable to non-caudate HCC ablation.

Impact of endoscopic ultrasound-guided radiofrequency ablation in managing pancreatic malignancy

Pancreatic malignancy is still the most lethal gastrointestinal malignancy. It has a very poor prognosis with low survival rate. Surgery is still the main treatment option for pancreatic malignancy. Most patients already have locally advanced and even late stage disease due to non-specific abdominal symptoms. Even though some cases are still suitable for surgical treatment, due to its aggressiveness adjuvant chemotherapy is becoming the standard treatment for controlling the disease. Radiofrequency ablation (RFA) is a thermal therapy that has been used as one of the standard treatments for liver malignancy. It can also be performed intraoperatively. There are several reports on percutaneous RFA treatment for pancreatic malignancy using transabdominal ultrasound and guided by computed tomography scan. However, due to its anatomical location and the risk of high radiation exposure, these methods seem to be very limited. Endoscopic ultrasound (EUS) has been widely used for pancreatic abnormality evaluation due to its ability to detect more accurately, especially small pancreatic lesions, compared to other imaging modalities. By the EUS approach, it is easier to achieve good visualization of tumor ablation and necrosis as the echoendoscope position is closer to the tumor area. Based on studies and a recent meta-analysis, EUS-guided RFA is a promising treatment approach for most pancreatic malignancy cases, but most studies only collected data from a small sample size. Larger studies are needed before clinical recommendations can be made.

Neoadjuvant Therapy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is characterized by low resection and high postoperative recurrence rates, and conventional treatment strategies have failed to meet clinical needs. Neoadjuvant therapy (NAT) is widely employed in the routine management of several solid tumors because it increases resectability and reduces the rate of postoperative recurrence. However, a consensus has not been reached regarding the effects of NAT on HCC. As systemic therapy, particularly targeted therapy and immunotherapy, is given for HCC treatment, accumulating evidence shows that the “spring” of NAT for HCC is imminent. In the future, HCC researchers should focus on identifying biomarkers for treatment response, explore the mechanisms of resistance, and standardize the endpoints of NAT.

The Efficacy of Radiofrequency Ablation for Bone Tumors Unsuitable for Radical Excision

Background

Bone tumors can cause severe pain and poor quality of life due to recurrence and non-achievement of complete remission after surgery, chemotherapy, or radiotherapy. Radiofrequency ablation (RFA) can be considered for minimally invasive treatment of bone tumors that are difficult to radically excise. In this study, RFA was performed for bone tumors that were difficult to radically excise and did not respond to surgery, chemotherapy, or radiotherapy due to their large sizes and/or locations. The purpose of this study was to retrospectively analyze the clinical characteristics and survival rates of bone tumors after RFA and provide one more treatment option for the future.

Methods

There were 43 patients with bone tumors who underwent percutaneous RFA at our hospital from April 2007 to October 2017. The median age of the patients was 59 years (range, 31–75 years), and the median follow-up duration was 67.2 months (range, 10.2–130.5 months). Of the 43 patients, 26 were male and 17 were female. Thirty-four cases were metastatic bone tumors, 5 were chordomas, 3 were osteosarcomas, and 1 was a giant cell tumor. Pain and functional ability of the patients were evaluated using a visual analog scale (VAS) and the Musculoskeletal Tumor Society (MSTS) functional scoring system, respectively. Scores were recorded preoperatively, 1 week postoperatively, and 4 weeks postoperatively. The 1-year, 2-year, and 5-year survival rates were evaluated using the Kaplan-Meier method.

Results

The mean VAS score was 8.21 preoperatively. The mean VAS score at 1 week, 4 weeks, 12 weeks, and 24 weeks postoperatively were 3.91, 3.67, 3.31, and 3.12, respectively. The mean preoperative MSTS score was 64.0% (range, 32%–87%). The mean postoperative MSTS score was 71.0% (range, 40%–90%). The 1-year, 2-year, and 5-year survival rates were 95.3%, 69.8%, and 30.2%, respectively.

Conclusions

As per our study findings, RFA was effective in reducing pain and improving functional ability of patients with bone tumors that were difficult to radically excise.

Interventional Radiology Approaches for Liver Metastases from Thyroid Cancer: A Case Series and Overview of the Literature

Background

Liver metastases (LMs) from thyroid cancer (TC) are relatively uncommon in clinical practice and their management is challenging. Interventional radiology loco-regional treatments (LRTs), including radiofrequency ablation (RFA) and trans-arterial chemoembolization (TACE), have been successfully employed to treat LMs from various types of cancer.

Methods

We analyzed the role of LRTs in the management of unresectable LMs from differentiated and medullary TCs performed at our institution from 2015 to 2020. A review of the available English literature regarding this topic was also performed.

Results

Six hepatic LRTs were performed in 4 TC patients with LMs, in 2 cases after the start of treatment with a tyrosine kinase inhibitor (TKI). A partial response was obtained in 2 patients; the diameter of the largest targeted lesion was 18 mm in both of them. The remaining procedures were performed on larger lesions and a stable disease was achieved in all but one case. Acute LRT-related complications were transient and mild. In literature, the largest studies were focused on TACE in LMs from MTC, showing good tolerance and remarkable disease control, especially in case of limited liver tumour involvement.

Conclusion

LRTs for LMs represent a valuable option for the treatment of metastatic TC in case of isolated hepatic progression or for symptoms relief, also after the start of TKI treatment as part of a multimodal approach. The best disease control is obtained when hepatic metastatic burden is limited. These procedures are generally well tolerated; however, a cautious multidisciplinary selection of the candidates is mandatory.

High Prevalence of Adrenal Remnant Tissue in Patients Undergoing Bilateral Adrenalectomy for Cushing's Disease

Bilateral adrenalectomy (BLA) is a treatment option for patients with Cushing's Disease (CD) if transsphenoidal pituitary surgery fails or is not a therapeutic option. For most patients, BLA eliminates endogenous glucocorticoid and mineralocorticoid production, but for a small number of patients, endogenous secretion of adrenal hormones from adrenal tissue continues or recurs, leading to signs and symptoms of hypercortisolism. If adrenal tissue is confined to the adrenal bed, it is considered adrenal remnant tissue, while if it is outside the adrenal bed, it is considered adrenal rest tissue. We retrospectively evaluated morning serum cortisol, nighttime serum cortisol, nighttime salivary cortisol, and 24-h urine free cortisol on at least three occasions in 10 patients suspected of having endogenous cortisol production. Imaging of adrenal remnant tissue was also reviewed. Ten of 51 patients who underwent BLA during this time period had adrenal remnant/rest tissue marked by detectable endogenous glucocorticoid production; 9 of the 10 patients had signs and symptoms of hypercortisolism. Localization and treatment proved difficult. We conclude that the incidence of adrenal remnant/rest tissue in those undergoing BLA following unsuccessful pituitary surgery was 12% although there may have been a selection bias affecting this prevalence. The first indication of remnant tissue occurrence is a reduction in glucocorticoid replacement with symptoms of hypercortisolism. If this occurs, endogenous cortisol production should be tested for by cortisol measurements using a highly specific cortisol assay while the patient is taking dexamethasone or no glucocorticoid replacement. Endocrinologists need to monitor the development of both adrenal remnant tissue and Nelson's syndrome following BLA.

c-Met/MAPK pathway promotes the malignant progression of residual hepatocellular carcinoma cells after insufficient radiofrequency ablation

Radiofrequency ablation (RFA) is popularly used in the treatment of hepatocellular carcinoma (HCC). However, the accelerated malignant progression of residual HCC cells after RFA is the main obstacle for the application of this technology in HCC treatment. In the present study, HepG2 cells, an established human HCC cell line, experienced repeatedly with heat treatment, survived cells, HepG2-H cells, were used to simulate residual HCC cells after RFA. The abilities of proliferation, colony formation, and migration were compared between HepG2 and HepG2-H cells. Then, RNA sequencing was used to explore the difference in genes expression between two groups of cells. Subsequently, the level of c-Met, one of membranous receptors of MAPK signal pathway, was measured by RT-qPCR and western blot; the effect of c-Met inhibition on the malignant progression of HepG2-H cells was evaluated. The results showed that HepG2-H cells exhibited higher abilities in the proliferation, colony formation, and migration than that of HepG2 cells. Moreover, differentially expressed genes between two groups of cells were prominently enriched in MAPK signal pathway. The level of c-Met in HepG2-H cells was significantly higher than that in HepG2 cells, and the inhibition in the activity of c-Met could repress the malignant behaviors of HepG2-H cells. These results indicated that the accelerated malignant progression of residual HCC cells after RFA can be partly attributed to the overexpression of c-Met and the activation of MAPK signal pathway. Therefore, we proposed that RFA followed by c-Met inhibitor intake maybe is a better treatment protocol for HCC.

A single-institutional experience with low dose stereotactic body radiation therapy for liver metastases

AIM

This study reports a single-institutional experience treating liver metastases with stereotactic body radiation therapy (SBRT).

MATERIALS AND METHODS

107 patients with 169 lesions were assessed to determine factors predictive for local control, radiographic response, and overall survival (OS). Machine learning techniques, univariate analysis, and the Kaplan-Meier method were utilized.

RESULTS

Patients were treated with a relatively low median dose of 30 Gy in 3 fractions. Fractions were generally delivered once weekly. Median biologically effective dose (BED) was 60 Gy, and the median gross tumor volume (GTV) was 12.16 cc. Median follow-up was 7.36 months. 1-year local control was 75% via the Kaplan-Meier method. On follow-up imaging, 43%, 40%, and 17% of lesions were decreased, stable, and increased in size, respectively. 1-year OS was 46% and varied by primary tumor, with median OS of 34.3, 25.1, 12.5, and 4.6 months for ovarian, breast, colorectal, and lung primary tumors, respectively. Breast and ovarian primary patients had better OS (p < 0.0001), and lung primary patients had worse OS (p = 0.032). Higher BED values, the number of hepatic lesions, and larger GTV were not predictive of local control, radiographic response, or OS. 21% of patients suffered from treatment toxicity, but no grade ≥3 toxicity was reported.

CONCLUSION

Relatively low-dose SBRT for liver metastases demonstrated efficacy and minimal toxicity, even for patients with large tumors or multiple lesions. This approach may be useful for patients in whom higher-dose therapy is contraindicated or associated with high risk for toxicity. OS depends largely on the primary tumor.

Biliary cooling during radiofrequency ablation of liver tumours close to central biliary tree: A systematic review and pooled analysis

INTRODUCTION

Biliary cooling during radiofrequency ablation (RFA) of liver tumour has been proposed as a protective measure for RFA-related biliary complications in cases whereby the RFA site is close to central biliary tree. This systematic review aims to assess the effect of biliary cooling during RFA on: 1) the development of biliary complications and 2) tumour recurrence rates at ablation site.

METHODOLOGY

A systematic literature search was performed using the PubMed/EMBASE databases using PRISMA methodology (2000-2019). The initial search yielded 75 reports which were potentially suitable for inclusion. Studies reporting at least one outcome of interest were considered to be suitable for inclusion. Conference abstracts, case reports and animal studies were excluded. Data was retrieved from each study on patient demographics, tumour characteristics, method of cooling, biliary complications, local tumour recurrence and duration of follow-up.

RESULTS

The final number of studies which met the inclusion criteria was 7, involving 100 patients. There were no randomized controlled trials identified after the literature search. The mean age of the patients included was 65 years. Biliary cooling was performed with the use of a nasobiliary tube in 4 out of 7 studies, via a choledochal incision in 2 out of 7 studies and through the cystic duct in a single study. The overall biliary stricture rate was 2% and the overall tumour recurrence rate at RFA treated site was 14.5%.

CONCLUSION

Biliary complications appear to be low after biliary cooling during RFA close to central biliary tree. More evidence is required to assess the tumour recurrence rates.

Fully laparoscopic thermo-ablation of liver malignancies with or without liver resection: tumor location is an independent local recurrence risk factor

BACKGROUND

The aim of this study was to analyze risk factors of local recurrence (LR) after exclusive laparoscopic thermo-ablation (TA) with or without associated liver resection.

METHODS

Between 2012 and 2017, among 385 patients who underwent 820 TA in our department, 65 (17%) patients (HCC = 11, LM = 54) had exclusive laparoscopic TA representing 112 lesions (HCC = 17, LM = 95). TA was associated with other procedures in 57% of cases (liver resection 81%). All TA were done without liver clamping. Median tumor size was 1.8 cm [ranges from 0.3 to 4.5], 18% of the lesions were larger than 3 cm in size and 11% close to major liver vessels. Tumors locations were 77.5% in right liver, 36% in S7&S8, and 46% in S7&S8&S4a.

RESULTS

Mortality was nil and morbidity rate 15.4% including Dindo-Clavien > II grade 3%. The median follow-up was 24 months [0.77-75]. Per lesion LR rate after TA was 18% (n = 19 patients) with a mean time of 7.6 months. Among patients with LR, 18 (95%) could have been re-treated successfully (new resection = 11, re-TA = 7). Multivariate analyses revealed that tumor location in S7 alone, S7&S8 and/or S7, S8, or S4a were independent risk factors of LR after TA.

CONCLUSIONS

Exclusive laparoscopic TA is a safe and an effective tool to treat liver malignancies with or without liver resection. Other than classical risk factors, tumor location in upper segments of the liver, are independent risk factors for LR.

Emerging hyperthermia applications for pediatric oncology

Local application of hyperthermia has a myriad of effects on the tumor microenvironment as well as the host's immune system. Ablative hyperthermia (typically > 55 °C) has been used both as monotherapy and adjuvant therapy, while mild hyperthermia treatment (39-45 °C) demonstrated efficacy as an adjuvant therapy through enhancement of both chemotherapy and radiation therapy. Clinical integration of hyperthermia has especially great potential in pediatric oncology, where current chemotherapy regimens have reached maximum tolerability and the young age of patients implies significant risks of late effects related to therapy. Furthermore, activation of both local and systemic immune response by hyperthermia suggests that hyperthermia treatments could be used to enhance the anticancer effects of immunotherapy. This review summarizes the state of current applications of hyperthermia in pediatric oncology and discusses the use of hyperthermia in the context of other available treatments and promising pre-clinical research.

Ablation or Resection for Colorectal Liver Metastases? A Systematic Review of the Literature

Background: Successful use of ablation for small hepatocellular carcinomas (HCC) has led to interest in the role of ablation for colorectal liver metastases (CRLM). However, there remains a lack of clarity about the use of ablation for colorectal liver metastases (CRLM), specifically its efficacy compared with hepatic resection. Methods: A systematic review of the literature on ablation or resection of colorectal liver metastases was performed using MEDLINE, Cochrane Library, and Embase until December 2018. The aim of this study was to summarize the evidence for ablation vs. resection in the treatment of CRLM. Results: This review identified 1,773 studies of which 18 were eligible for inclusion. In the majority of the studies, overall survival (OS) and disease-free survival (DFS) were significantly higher and local recurrence (LR) rates were significantly lower in the resection groups. On subgroup analysis of solitary CRLM, resection was associated with improved OS, DFS, and reduced LR. Three series assessed the outcome of resection vs. ablation for technically resectable CRLM, and showed improved outcome in the resection group. In fact, there were no studies showing a survival advantage of ablation compared to resection in the treatment of CRLM. Conclusions: Resection remains the "gold standard" in the treatment of CRLM and should not be replaced by ablation at present. This review supports the use of ablation only as an adjunct to resection and as a single treatment option when resection is not safely possible.

Factors predicting ablation site recurrence following percutaneous microwave ablation of colorectal hepatic metastases

BACKGROUND

Microwave ablation (MWA) is a recognised treatment option for liver metastases. The size of the tumour is a well-established factor that influences the success of MWA. However, the effect of "heat sink" on the success of MWA for hepatic metastases is unclear. The aim of this study was to determine whether heat sink effect is a factor that contributes to ablation site recurrence (ASR).

METHODS

A prospectively maintained database of patients who underwent percutaneous MWA for treatment of colorectal liver metastases was analysed. Imaging and demographic characteristics were compared between metastases that recurred following ablation and those that did not. Proximity to a large hepatic vein was defined as <10 mm.

RESULTS

126 ablations in 87 patients met the inclusion criteria and were studied over a median follow-up period of 28 (12-75) months. ASR was detected in 43 ablations (34%) and was associated with clinical risk score (CRS) ≥2 (OR 2.2 95% CI 1.3-3.3, p = 0.029), metastasis size (OR 0.953 95% CI (0.929-0.978), p < 0.001) and proximity to a large hepatic vein (OR 7.5 95%CI 2.4-22.8, p < 0.001). Proximity to a large hepatic vein was not associated with reduced overall survival (OS) but was associated with liver-specific recurrence (HR 4.7 95%CI 1.7-12.5, p = 0.004).

CONCLUSIONS

In addition to tumour size proximity to large hepatic venous structures is an independent predictor of ASR and liver-specific recurrence following MWA. However, this was not associated with overall survival.

Impact of concomitant ablation on the perioperative outcomes of patients with colorectal liver metastases undergoing hepatectomy: a propensity score matched nationwide analysis

BACKGROUND

Intraoperative ablation (IA) is often performed at the time of liver resection (LR) for colorectal liver metastases (CRLMs) but its impact on postoperative outcomes remains poorly understood.

METHODS

The ACS-NSQIP targeted hepatectomy database was used to identify patients who underwent LR vs LR + IA for CRLMs during 2014-2016. Perioperative outcomes were compared following propensity score match based on age, receipt of neoadjuvant therapy, operative approach, liver resection type, tumor diameter and number of metastases.

RESULTS

Among 1,384 patients, 692 (50%) underwent LR alone and 692 (50%) underwent LR + IA. After propensity score matching, overall morbidity (22% vs 13%, P < 0.0001) was increased among patients undergoing LR alone compared to LR + IA, whereas mortality did not differ (1.1% vs 0.8%, P=0.5911). On multivariable analysis, ASA class ≥3 (OR: 1.5, 95% CI: 1.06-2.3), preoperative biliary stent (OR: 3.5, 95% CI: 0.9-13.01), biliary reconstruction (OR: 5.02, 95% CI: 1.3-18.6), operative time > 245 minutes (OR: 1.8, 95% CI:1.3-2.4) and IA (OR:0.5, 95% CI:0.3-0.7) were associated with overall morbidity.

CONCLUSIONS

In this propensity matched nationwide analysis of patients undergoing LR for CRLM, the use of concomitant IA was associated with decreased postoperative morbidity compared to LR alone. These findings suggest that IA combined with LR is a safe approach that may expand the number of patients who are candidates for curative-intent surgical strategies.

Neoadjuvant and adjuvant treatment strategies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common liver malignancy worldwide and a major cause of cancer-related mortality for which liver resection is an important curative-intent treatment option. However, many patients present with advanced disease and with underlying chronic liver disease and/or cirrhosis, limiting the proportion of patients who are surgical candidates. In addition, the development of recurrent or de novo cancers following surgical resection is common. These issues have led investigators to evaluate the benefit of neoadjuvant and adjuvant treatment strategies aimed at improving resectability rates and decreasing recurrence rates. While high-level evidence to guide treatment decision making is lacking, recent advances in locoregional and systemic therapies, including antiviral treatment and immunotherapy, raise the prospect of novel approaches that may improve the outcomes of patients with HCC. In this review, we evaluate the evidence for various neoadjuvant and adjuvant therapies and discuss opportunities for future clinical and translational research.

Endoscopic Ultrasound-Guided Ablation of Liver Tumors

"Endoscopic ultrasound (EUS)-guided ablative therapies have advanced significantly and have led to experimental applications in locations that have been difficult to image and/or reach with percutaneous approaches, such as the caudate and left lobe of the liver. EUS-guided treatments of the liver are under development. The literature has shown that many percutaneous ablative techniques are readily adaptable for EUS. In this review, the authors discuss the current developments on EUS-guided ablation of liver tumors, including injection of sclerosants, thermal therapy, and EUS-guided portal injection of chemotherapy."

Early modifications of circulating microRNAs levels in metastatic colorectal cancer patients treated with regorafenib

Biomarkers able to improve the cost/benefit ratio are urgently needed for metastatic colorectal cancer patients that are eligible to receive regorafenib. Here, we measured plasma levels of ten circulating microRNAs (c-miRNAs) and we investigated their early changes during treatment, as well as possible correlation with clinical outcome. Ten literature-selected c-miRNAs were quantified by qRT-PCR on plasma samples collected at baseline (d1) and after 15 days of treatment (d15). C-miRNAs showing significant changes were further analyzed to establish correlations with outcome. A decision tree-based approach was employed to define a c-miRNA signature able to predict the outcome. Results achieved in an exploratory cohort were tested in a validation group. In the exploratory cohort (n = 34), the levels of c-miR-21 (p = 0.06), c-miR-141 (p = 0.04), and c-miR-601 (p = 0.01) increased at d15 compared with d1. A c-miRNA signature involving c-miR-21, c-miR-221, and c-miR-760 predicted response to treatment (p < 0.0001) and was significantly associated to PFS (HR = 10.68; 95% CI 3.2-35.65; p < 0.0001). In the validation cohort (n = 36), the increase in c-miR-21 (p = 0.02) and c-miR-601 (p = 0.02) levels at d15 was confirmed, but the associations with outcome were not. Our data indicate that early changes of c-miRNA levels might be influenced by regorafenib treatment. However, further studies are needed to establish the predictive power of such modifications.

Robotic versus Freehand Needle Positioning in CT-guided Ablation of Liver Tumors: A Randomized Controlled Trial

Purpose To compare the accuracy of freehand versus robotic antenna placement in CT-guided microwave ablation (MWA) of liver tumors. Materials and Methods This study was conducted as a prospective single-center nonblinded randomized controlled trial (Netherlands Trial Registry, NTR6023). Eligible study participants had undergone clinically indicated CT-guided MWA of liver tumors and were able to receive a CT contrast agent. Randomization was performed per tumor after identification on contrast material-enhanced CT images. The primary outcome was the number of antenna repositionings, which was compared by using the Mann-Whitney U test. Secondary outcomes were lateral targeting error stratified by in-plane and out-of-plane targets and targeting time. Results Between February 14 and November 12, 2017, 31 participants with a mean age of 63 years (range, 25-88 years) were included: 17 women (mean age, 57 years; range, 25-77 years) and 14 men (mean age, 70 years; range, 52-88 years). The freehand study arm consisted of 19 participants, while the robotic study arm consisted of 18 participants; six participants with multiple tumors were included in both arms. Forty-seven tumors were assessed; five tumors were excluded from the analysis because of technical limitations. In the robotic arm, no antenna repositioning was required. In the freehand arm, a median of one repositioning was required (range, zero to seven repositionings; P < .001). For out-of-plane targets, lateral targeting error was 10.1 mm ± 4.0 and 5.9 mm ± 2.9 (P = .007) for freehand and robotic procedures, respectively, and for in-plane targets, lateral targeting error was 6.2 mm ± 2.7 and 7.7 mm ± 5.9, respectively (P = .51). Mean targeting time was 19 minutes (range, 8-55 minutes) and 36 minutes (range, 3-70 minutes; P = .001) for freehand and robotic procedures, respectively. Conclusion Robotic antenna guidance reduces the need for antenna repositioning in microwave ablation to accurately target liver tumors and increases accuracy for out-of-plane targets. However, targeting time was greater with robotic guidance than with freehand targeting. © RSNA, 2019.

Oliguric acute kidney injury after microwave ablation of large liver tumors: incidence and preventive measures

PURPOSE

Acute kidney injury (AKI), especially oliguric AKI, is a recognized complication following microwave ablation (MWA) of large liver tumors. This study evaluated the clinical features, mechanisms, risk factors and prevention strategies for oliguric AKI after MWA of large liver tumors.

METHODS

From March 2011 to May 2015, 441 patients with liver tumors ≧5 cm received MWA in our hospital. The clinical features, prevention strategies, further mechanisms and possible risk factors for oliguric AKI after MWA were analyzed.

RESULTS

One hundred four (23.6%) patients had AKI after MWA; 11 (10.6%) patients had oliguric AKI, and 93 (89.4%) patients had nonoliguric AKI. All patients with nonoliguric AKI recovered without any special treatments. The eleven patients with oliguric AKI received appropriate treatments and had completely normal renal function three months later. Using double needles for ablation was a risk factor for nonoliguric AKI, while high preoperative levels of red blood cells (RBC), hemoglobin (HGB) and albumin (Alb) were risk factors for oliguric AKI. The decrease levels of hemoglobin were significantly high in oliguric AKI patients (p < .05). Patients with oliguric AKI had abnormally high postoperative transaminase and renal function indicators. Compared to postoperative prevention, intraoperative prevention significantly lowered the occurrence of oliguric AKI (0% vs. 3.7%, p = .018) and shortened the hospital stay.

CONCLUSIONS

Patients who underwent MWA for large liver tumors are prone to develop oliguric AKI. Implementation of intraoperative strategies during MWA can effectively prevent the occurrence of this severe complication.

Long-term survival after percutaneous irreversible electroporation of inoperable colorectal liver metastases

Background

For colorectal liver metastases (CRLM) that are not amenable to surgery or thermal ablation, irreversible electroporation (IRE) is a novel local treatment modality and additional option.

Methods

This study is a retrospective long-term follow-up of patients with CRLM who underwent IRE as salvage treatment.

Results

Of the 24 included patients, 18 (75.0%) were male, and the median age was 57 (range: 28-75) years. The mean time elapsed from diagnosis to IRE was 37.9±37.3 months. Mean overall survival was 26.5 months after IRE (range: 2.5-69.2 months) and 58.1 months after diagnosis (range: 14.8-180.1 months). One-, three-, and five-year survival rates after initial diagnosis were 100.0%, 79.2%, and 41.2%; after IRE, the respective survival rates were 79.1%, 25.0%, and 8.3%. There were no statistically significant differences detected in survival after IRE with respect to gender, age, T- or N-stage at the time of diagnosis, size of metastases subject to IRE, number of hepatic lesions, or time elapsed between IRE and diagnosis.

Conclusion

For nonresectable CRLM, long-term survival data emphasize the value of IRE as a new minimally invasive local therapeutic approach in multimodal palliative treatment, which is currently limited to systemic or regional therapies in this setting.

New microwave ablation system for unresectable liver tumors that forms large, spherical ablation zones

BACKGROUND AND AIM

The aim of this study was to assess the efficacy of a new microwave ablation (MWA) system, the Emprint Ablation System, for the ablation of unresectable large liver tumors (≥ 30 mm).

METHODS

Twenty-one hepatic tumors (mean diameter, 34.7 mm) from 21 patients who underwent percutaneous MWA were included in this cross-sectional study. A volume analyzer based on computed tomography imaging was used for all patients within the month before and month after the procedure to evaluate the shape and volume of ablation zones. In addition, computed tomography imaging was performed again 3 months after the procedure to evaluate the presence of residual tumors and local recurrence.

RESULTS

Mean ablation time was 11.3 min, and mean overall procedure time was 33.4 min. An ablated adrenal gland-induced Takotsubo (stress) cardiomyopathy occurred immediately after MWA as a major complication in one patient. Roundness index A, B, and C presented a mean value of 0.94, 0.94, and 1.01, respectively (all values near 1 is a perfect sphere), indicating that a spherical ablation zone was achieved. The mean ablation volume was larger than the volume of tumors (24.5 vs 41.7 cm³ ). Residual tumors were confirmed in only 4.8% of tumors after a single ablation session. There was no local recurrence.

CONCLUSIONS

In our experience, the new MWA system provides an effective treatment option for unresectable large liver tumors. However, to ablate the liver tumors safely, it is necessary to consider the surrounding organs, such as the adrenal glands.

Altmetric Versus Bibliometric Perspective Regarding Publication Impact and Force

BACKGROUND

Bibliometric and Altmetric analyses highlight key publications, which have been considered to be the most influential in their field. The hypothesis was that highly cited articles would correlate positively with levels of evidence and Altmetric scores (AS) and rank.

METHODS

Surgery as a search term was entered into Thomson Reuter's Web of Science database to identify all English-language full articles. The 100 most cited articles were analysed by topic, journal, author, year, institution, and AS.

RESULTS

By bibliometric criteria, eligible articles numbered 286,122 and the median (range) citation number was 574 (446-5746). The most cited article (Dindo et al.) classified surgical complications by severity score (5746 citations). Annals of Surgery published most articles and received most citations (26,457). The country and year with most publications were the USA (n = 50) and 1999 (n = 11). By Altmetric criteria, the article with the highest AS was by Bigelow et al. (AS = 53, hypothermia's role in cardiac surgery); Annals of Surgery published most articles, and the country and year with most publications were USA (n = 4) and 2007 (n = 3). Level-1-evidence articles numbered 13, but no correlation was found between evidence level and citation number (SCC 0.094, p = 0.352) or AS (SCC = 0.149, p = 0.244). Median AS was 0 (0-53), and in articles published after the year 2000, AS was associated with citation number (r = 0.461, p = 0.001) and citation rate index (r = 0.455, p = 0.002). AS was not associated with journal impact factor (r = 0.160, p = 0.118).

CONCLUSION

Bibliometric and Altmetric analyses provide important but different perspectives regarding article impact, which are unrelated to evidence level.

Extracellular matrix collagen I promotes the tumor progression of residual hepatocellular carcinoma after heat treatment

Background

Accelerated malignant behaviors induced by insufficient thermal ablation have been increasingly reported, however, the exact mechanisms are still unclear. Here, we investigated the importance of the extracellular matrix (ECM) in modulating the progression of residual hepatocellular carcinoma (HCC) after heat treatment.

Methods

Heat-exposed residual HCC cells were cultured in different ECM gels. We used basement membrane gel (Matrigel) to simulate the normal microenvironment and collagen I to model the pathological stromal ECM. The alterations of morphology and parameters of proliferation, epithelial-mesenchymal transition (EMT) and stemness were analyzed in vitro and in vivo.

Results

Increased collagen I deposition was observed at the periablational zone after incomplete RFA of HCC in a xenograft model. The markers of cell proliferation, EMT, motility and progenitor-like traits of heat-exposed residual HCC cells were significantly induced by collagen I as compared to Matrigel (p values all < 0.05). Importantly, collagen I induced the activation of ERK phosphorylation in heat-exposed residual HCC cells. ERK1/2 inhibitor reversed the collagen I-promoted ERK phosphorylation, cell proliferative, protrusive and spindle-like appearance of heat-treated residual HCC cells in vitro. Moreover, collagen I promoted the in vivo tumor progression of heat-exposed residual HCC cells, and sorafenib markedly reversed the collagen I-mediated protumor effects.

Conclusions

Our findings demonstrate that collagen I could enhance the aggressive progression of residual HCC cells after suboptimal heat treatment and sorafenib may be a treatment approach to thwart this process.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4820-9) contains supplementary material, which is available to authorized users.

Early Results after Radiofrequency-Assisted Liver Resection

Aims and background

Intraoperative blood loss during liver resection remains a major concern due to its association with higher postoperative complications and shorter long-term survival. The aim of this study was to assess the feasibility and safety of a novel concept for liver resection using a radiofrequency energy-assisted technique.

Methods

From January 2001 to July 2002, 42 patients were operated on using radiofrequency energy-assisted liver resection. Radiofrequency energy was applied along the resection edge to create a ‘zone of desiccation’ prior to resection with a scalpel.

Results

Median resection time was 50 mins (range, 30–110). The median blood loss during resection was 30 mL (range, 15–992). Mean preoperative and postoperative hemoglobin values were 13.7 g/dL (SD ± 1.6) and 11.8 g/dL (SD ± 1.4), respectively. No blood transfusion was registered, nor was any mortality observed. There were 3 postoperative complications, one subphrenic abscess, one chest infection and one biliary leak from a hepatico-jejunostomy. Median postoperative stay was 8 days (range, 5–86).

Conclusions

Liver resection assisted by radiofrequency energy is feasible, easy and safe. This novel technique offers a new method for ‘transfusion-free’ resection without the need for sutures, ties, staples, tissue glue or admission to an intensive care unit.

Reduced microperfusion due to portal vein thrombosis: Impact on the outcome of percutaneous thermal tumor ablation

PURPOSE

To determine the influence of pre-interventionally existing portal vein thrombosis on the ablation success of percutaneous tumor ablation of HCC.

MATERIALS AND METHODS

15 patients with HCC and pre-existing portal vein thrombosis underwent thermal tumor ablation. We retrospectively analyzed the pre- and post-interventionally performed CT and MRI scans in terms of technical success as well as the complication rate. The portal vein thrombosis was classified into segmental, lobar and central thrombus.

RESULTS

In 13/15 cases (87%) complete ablation with no evidence of residual tumor tissue was seen 6 weeks after the procedure in contrast-enhanced MRI scans and contrast-enhanced ultrasound (CEUS). No major and 2 minor complications were observed after the ablation procedure.

CONCLUSION

Reduced perfusion due to pre-interventionally existing portal vein thrombosis has no significant impact on the ablation success or the complication rate.

The Role of Protein Loss and Denaturation in Determining Outcomes of Heating, Cryotherapy, and Irreversible Electroporation on Cardiomyocytes

Atrial fibrillation (AF) currently affects millions of people in the U.S. alone. Focal therapy is an increasingly attractive treatment for AF that avoids the debilitating effects of drugs for disease control. Perhaps the most widely used focal therapy for AF is heat-based radiofrequency (heating), although cryotherapy (cryo) is rapidly replacing it due to a reduction in side effects and positive clinical outcomes. A third focal therapy, irreversible electroporation (IRE), is also being considered in some settings. This study was designed to help guide treatment thresholds and compare mechanism of action across heating, cryo, and IRE. Testing was undertaken on HL-1 cells, a well-established cardiomyocyte cell line, to assess injury thresholds for each treatment method. Cell viability, as assessed by Hoechst and propidium iodide (PI) staining, was found to be minimal after exposure to temperatures ≤−40 °C (cryo), ≥60 °C (heating), and when field strengths ≥1500 V/cm (IRE) were used. Viability was then correlated to protein denaturation fraction (PDF) as assessed by Fourier transform infrared (FTIR) spectroscopy, and protein loss fraction (PLF) as assessed by bicinchoninic acid (BCA) assay after the three treatments. These protein changes were assessed both in the supernatant and the pellet of cell suspensions post-treatment. We found that dramatic viability loss (≥50%) correlated strongly with ≥12% protein change (PLF, PDF or a combination of the two) in every focal treatment. These studies help in defining both cellular thresholds and protein-based mechanisms of action that can be used to improve focal therapy application for AF.

The relationship between applied energy and ablation zone volume in patients with hepatocellular carcinoma and colorectal liver metastasis

Objectives

To study the ratio of ablation zone volume to applied energy in computed tomography (CT)-guided radiofrequency ablation (RFA) and microwave ablation (MWA) in patients with hepatocellular carcinoma (HCC) in a cirrhotic liver and in patients with colorectal liver metastasis (CRLM).

Methods

In total, 90 liver tumors, 45 HCCs in a cirrhotic liver and 45 CRLMs were treated with RFA or with one of two MWA devices (MWA_A and MWA_B), resulting in 15 procedures for each tumor type, per device. Device settings were recorded and the applied energy was calculated. Ablation volumes were segmented on the contrast-enhanced CT scans obtained 1 week after the procedure. The ratio of ablation zone volume in milliliters to applied energy in kilojoules was determined for each procedure and compared between HCC (R_HCC) and CRLM (R_CRLM), stratified according to ablation device.

Results

With RFA, R_HCC and R_CRLM were 0.22 mL/kJ (0.14–0.45 mL/kJ) and 0.15 mL/kJ (0.14–0.22 mL/kJ; p = 0.110), respectively. With MWA_A, R_HCC was 0.81 (0.61–1.07 mL/kJ) and R_CRLM was 0.43 (0.35–0.61 mL/kJ; p = 0.001). With MWA_B, R_HCC was 0.67 (0.41–0.85 mL/kJ) and R_CRLM was 0.43 (0.35–0.61 mL/kJ; p = 0.040).

Conclusions

With RFA, there was no significant difference in energy deposition ratio between tumor types. With both MWA devices, the ratios were higher for HCCs. Tailoring microwave ablation device protocols to tumor type might prevent incomplete ablations.

Key Points

• HCCs and CRLMs respond differently to microwave ablation

• For MWA, CRLMs required more energy to achieve a similar ablation volume

• Tailoring ablation protocols to tumor type might prevent incomplete ablations

Two-Stage Hepatectomy vs One-Stage Major Hepatectomy with Contralateral Resection or Ablation for Advanced Bilobar Colorectal Liver Metastases

BACKGROUND

Both 2-stage hepatectomy (TSH) and 1-stage hepatectomy (OSH) represent feasible strategies for resection of advanced bilobar colorectal liver metastases (CLM). However, the influence of the surgical approach on postoperative outcomes and overall survival (OS) is unknown. To define the optimal surgical approach for advanced bilobar CLM requiring right hemihepatectomy, we compared short-term and long-term outcomes after TSH and OSH with contralateral resection or radiofrequency ablation (RFA).

STUDY DESIGN

We retrospectively reviewed 227 patients with bilobar CLM, who underwent right or extended right hepatectomy with treatment of synchronous CLM in segments I, II, and/or III, between 1998 and 2015. Postoperative outcomes and OS were compared between patients who underwent TSH and those who underwent OSH.

RESULTS

Of the 227 patients, 126 (56%) underwent at least the first stage of TSH, and 101 (44%) underwent OSH, 29 (13%) without RFA and 72 (32%) with RFA. Two-stage hepatectomy was associated with a lower incidence of postoperative major complications (14% vs 26%, p = 0.03) and postoperative hepatic insufficiency (6% vs 20%, p = 0.001) than OSH. The 5-year OS rate was higher for patients assigned to TSH than for those who underwent OSH (35% vs 24%, p = 0.016). Patients who completed both stages of TSH had a higher 5-year OS rate than patients who underwent OSH without RFA (50% vs 20%, p = 0.023) or OSH with RFA (50% vs 24%, p < 0.0001).

CONCLUSIONS

In patients with advanced bilobar CLM, TSH is associated with fewer complications than OSH. Both TSH in intention-to-treat analysis and completed TSH in as-treated analysis were associated with better OS than OSH.

Magnetic Resonance Mediated Radiofrequency Ablation

To introduce magnetic resonance mediated radiofrequency ablation (MR-RFA), in which the MRI scanner uniquely serves both diagnostic and therapeutic roles. In MR-RFA scanner-induced RF heating is channeled to the ablation site via a Larmor frequency RF pickup device and needle system, and controlled via the pulse sequence. MR-RFA was evaluated with simulation of electric and magnetic fields to predict the increase in local specific-absorption-rate (SAR). Temperature-time profiles were measured for different configurations of the device in agar phantoms and ex vivo bovine liver in a 1.5 T scanner. Temperature rise in MR-RFA was imaged using the proton resonance frequency method validated with fiber-optic thermometry. MR-RFA was performed on the livers of two healthy live pigs. Simulations indicated a near tenfold increase in SAR at the RFA needle tip. Temperature-time profiles depended significantly on the physical parameters of the device although both configurations tested yielded temperature increases sufficient for ablation. Resected livers from live ablations exhibited clear thermal lesions. MR-RFA holds potential for integrating RF ablation tumor therapy with MRI scanning. MR-RFA may add value to MRI with the addition of a potentially disposable ablation device, while retaining MRI's ability to provide real time procedure guidance and measurement of tissue temperature, perfusion, and coagulation.

Interventional radiofrequency ablation: A promising therapeutic modality in the management of malignant biliary and pancreatic duct obstruction

Background: Malignant biliary and/or pancreatic obstruction has often encountered in the advanced stages of periampullary and cholangicarcinomas. Habib^TM Radiofrequency (RF) ablation has been successfully used in the management of various cancers of liver and pancreas. Percutaneous HPB probe (EMcision Ltd, London, UK) is a new addition to this class of tools. It is an endoluminal Radiofrequency (RF) catheter which works on the principle of ablation and induces coagulative necrosis to recanalize the obstructed duct. The aim of this study is to address the technical details of canalization, feasibilities and outcomes of percutaneous endo-luminal Radiofrequency (RF) catheter in patients with unresectable malignancy with obstructed bile and pancreatic duct (PD). Material and Method: A total of 134 patients with inoperable malignant obstruction of biliary and PD underwent RF based percutaneous endoluminal RF ablation in a tertiary referral centre between December 15^th, 2010 to August 7^th, 2015. This device was used in a sequential manner with an intent to recanalize the obstructed. Following the initial catheter drainage of the duct, subsequent percutaneous endobiliary RF ablation, the metallic stent was placed to recanalize the obstructed bile and PD secondary to unresectable malignancy under real-time fluoroscopic guidance. Results: The percutaneous RF based ablation of obstructed bile duct and PD with metallic stent placement was successfully achieved in 130 (97.01%) cases. The three failures were noted in cases of biliary obstruction whilst, one with PD obstruction. The patency restored in 124 and patients, where the procedure was successfully completed and revealed clinical improvement reported. Conclusion: The percutaneous endoluminal RF based ablation of obstructed duct with metallic stent placement appeared to be a safe, effective procedure and may improve survival in patients with advanced stage cancer presenting with biliary and PD obstruction. Considering the above mentioned evidence, this modality may stand ahead of stenting alone. This could be considered as viable modality in management of such patients where very limited treatment options are available.

Ex vivo human bile duct radiofrequency ablation with a bipolar catheter

BACKGROUND

Management of the primary and secondary tumors of the bile ducts still remains as a major clinical challenge. Radiofrequency (RF) ablation (RFA) of these tumors is feasible but the effect of RF energy on the human common bile duct (CBD) and surrounding tissues has not been investigated. This pilot study aimed to determine the relationship between RF energy and the depth of ablation in the normal human CBD.

METHODS

The study was performed on fresh ex vivo human biliary-pancreatic tissue which had been resected for a pancreatic cyst or mass. The study was conducted within 15 min after resection. A bipolar Habib RFA catheter was placed into the middle of the intact CBD, and three different (5, 7, 10 W) power settings were applied over a 90-s period by an RF generator. Gross and histological examinations were performed. The depth of coagulation necrosis in CBD and the effect of RFA on CBD wall and surrounding pancreas tissue were determined by microscopic examination.

RESULTS

The study included eight tissue samples. 5 W power was applied to three sites and RFA caused only focal epithelial necrosis limited to the CBD mucosa. 7 and 10 W were applied to five sites and coagulation necrosis occurred in all cases. Microscopically, necrosis was transmural, involved accessory bile duct glands, and extended to the surrounding pancreatic tissue in four of these cases. Macroscopically, RFA resulted in circumferential white-yellowish color change extending approximately 2 cm of the CBD.

CONCLUSION

Bipolar RF energy application with 5 W resulted in limited ablation on CBD wall. However, 7 and 10 W generated tissue necrosis which extended through the CBD wall and into surrounding pancreas tissue. Endoscopic biliary RFA is an effective technique for local biliary tissue ablation but the use of high energy may injure surrounding tissue.

Non-invasive monitoring of branched Au nanoparticle-mediated photothermal ablation

Nanoparticle-mediated photothermal therapy for treatment of different types of tumors has attracted tremendous attention in recent years. One major factor that drives this therapy is the ability to carefully control and prevent inadvertent damage to local tissues, while focusing therapeutic heating to specific regions of the tumor tissues. To this end, it is critical to generate efficient heating in the targeted tumors while monitoring the extent and distribution of heating. In our study, we demonstrated the photothermal heating properties of our synthesized branched Au nanoparticles (b-AuNPs) using non-invasive MR thermometry (MRT) techniques to assess its effects both in vitro and in vivo. 75 nm b-AuNPs were synthesized; these b-AuNPs demonstrated strong near infrared (NIR) absorption and high heat transducing efficiency. Proton resonance frequency MRT approaches for monitoring b-AuNPs mediated heating were validated using in vitro agar phantoms and further evaluated during in vivo animal model tumor ablation studies. In vitro phantom studies demonstrated a strong linear correlation between MRT and reference-standard thermocouple measurements of b-AuNPs-mediated heating upon NIR laser irradiation; temperatures increased with both an increase in laser power and increased exposure duration. Localized photothermal heating in regions containing the b-AuNPs was confirmed through MRT generated temperature maps acquired serially at increasing depths during both phantom and in vivo studies. Our results suggested that b-AuNPs exposed to NIR radiation produced highly efficient localized heating that can be accurately monitored dynamically using non-invasive MRT measurements. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2352-2359, 2017.

Mortality and hemorrhagic complications associated with radiofrequency ablation for treatment of hepatocellular carcinoma in patients on hemodialysis for end-stage renal disease: A nationwide survey

BACKGROUND AND AIM

Because of the rarity of invasive treatment for hepatocellular carcinoma (HCC) in patients on hemodialysis (HD) for end-stage renal disease (ESRD), the risks associated with radiofrequency ablation (RFA) in such patients remain uncertain. We used a nationwide database to investigate in-hospital mortality and hemorrhagic complications following RFA in patients on HD for ESRD.

METHODS

Using the Japanese Diagnosis Procedure Combination database, we enrolled patients on HD for ESRD who underwent RFA for HCC. For each patient, we randomly selected up to four non-dialyzed patients using a matched-pair sampling method based on patient age, sex, treatment hospital, and treatment year. In-hospital mortality and hemorrhagic complications were compared between dialyzed and non-dialyzed patients following RFA.

RESULTS

We compared matched-pair samples of 437 dialyzed and 1345 non-dialyzed patients. In patients on HD for ESRD, mortality was significantly lower in those aged ≤70 years than in older patients (P = 0.02). In-hospital mortality was significantly higher in dialyzed ESRD patients than in non-dialyzed patients (1.1% vs 0.15%, respectively; odds ratio = 7.77, P < 0.001). Hemorrhagic complications differed significantly between dialyzed ESRD patients and non-dialyzed patients (3.4% vs 0.87%, respectively; odds ratio = 4.75, P < 0.001).

CONCLUSIONS

In-hospital mortality following RFA was higher in dialyzed ESRD patients than in non-dialyzed patients. The indications for RFA in dialysis-dependent patients should be considered carefully. Patient age may be a useful indicator when considering RFA for HCC in patients on HD for ESRD.

Combined photothermal-chemotherapy of breast cancer by near infrared light responsive hyaluronic acid-decorated nanostructured lipid carriers

In this study, a novel type of hyaluronic acid (HA)-decorated nanostructured lipid carrier (NLC) was prepared and investigated as a light-triggered drug release and combined photothermal-chemotherapy for cancer treatment. Polyhedral gold nanoparticles (Au NPs) with an average size of 10 nm were synthesized and co-encapsulated with doxorubicin (DOX) in the matrix of NLCs with a high drug loading efficiency (above 80%). HA decoration was achieved by the electrostatic interaction between HA and CTAB on the NLC surface. A remarkable temperature increase was observed by exposing the Au NP-loaded NLCs to an NIR laser, which heated the samples sufficiently (above 40 °C) to kill tumor cells. The entrapped DOX exhibited a sustained, stepwise NIR laser-triggered drug release pattern. The biocompatibility of the NLCs was investigated by MTT assay and the cell viability was maintained above 85%, even at high concentrations. The intracellular uptake of free DOX and entrapped DOX, observed by confocal microscopy, revealed two distinct uptake mechanisms, i.e. passive diffusion and endocytosis, respectively. In particular, internalization of the HA-Au-DOX-NLCs was more extensively enhanced than the Au-DOX-NLCs, which was attributed to HA-CD44 receptor-mediated endocytosis. Meanwhile, the internalized NLCs successfully escaped from the lysosomes, increasing the intracellular DOX. The HA-Au-DOX-NLCs IC₅₀ value decreased from 2.3 to 0.6 μg ml^-1 with NIR irradiation at 72 h, indicating the excellent synergistic antitumor effect of photothermal-chemotherapy. The photothermal ablation was further confirmed by a live/dead cell staining assay. Thus, a combined photothermal-chemotherapy approach has been proposed as a promising strategy for cancer treatment.

Parenchymal sparing surgery for colorectal liver metastases: The need for a common definition

BACKGROUND

The definition of parenchymal sparing surgery (PSS) for colorectal liver metastases (CRLM) diverges requiring a clarification of the concept.

METHOD

A consecutive series of patients were treated by PSS for their CRLMs, either by resection or intra-operative ablation (IOA), whenever possible a one-stage surgery and minimal usage of portal vein embolization. Post-operative complications were the primary endpoint with a special focus on post-operative liver failure.

RESULTS

Three hundred and eighty-seven patients underwent a PSS out of which 328 patients received a median of 9 pre-operative cycles of chemotherapy. One hundred and twenty-eight patients had a major resection, combined with IOA in 137 patients and IOA alone in 50 cases. The 5yr-overall survival was 50.3%. There was no difference in post-operative complications between minor and major resections, validating our PSS definition based on the Tumor burden/Healthy liver ratio and not just the retrieved volume.

CONCLUSIONS

PSS is defined as a high ratio of tumoral burden per specimen retrieved while favoring one-stage surgery approach. Our series, using combined resections and IOAs, matches this definition well. Furthermore, complications were correlated neither to chemotherapy nor to liver-induced toxicities, contrary to extended hepatectomies.

Percutaneous thermal ablation for stage IA non-small cell lung cancer: long-term follow-up

Background

Surgical resection is the most effective curative therapy for non-small cell lung cancer (NSCLC). However, many patients are unable to tolerate resection secondary to poor reserve or comorbid disease. Radiofrequency ablation (RFA) and microwave ablation (MWA) are methods of percutaneous thermal ablation that can be used to treat medically inoperable patients with NSCLC. We present long-term outcomes following thermal ablation of stage IA NSCLC from a single center.

Methods

Patients with stage IA NSCLC and factors precluding resection who underwent RFA or MWA from July 2005 to September 2009 were studied. CT and PET-CT scans were performed at 3 and 6 month intervals, respectively, for first 24 months of follow-up. Factors associated with local progression (LP) and overall survival (OS) were analyzed.

Results

Twenty-one patients underwent 21 RFA and 4 MWA for a total of 25 ablations. Fifteen patients had T1a and six patients had T1b tumors. Mean follow-up was 42 months, median survival was 39 months, and OS at three years was 52%. There was no significant difference in median survival between T1a nodules and T1b nodules (36 vs. 39 months, P=0.29) or for RFA and MWA (36 vs. 50 months, P=0.80). Ten patients had LP (47.6%), at a median time of 35 months. There was no significant difference in LP between T1a and T1b tumors (22 vs. 35 months, P=0.94) or RFA and MWA (35 vs. 17 months, P=0.18). Median OS with LP was 32 months compared to 39 months without LP (P=0.68). Three patients underwent repeat ablations. Mean time to LP following repeat ablation was 14.75 months. One patient had two repeat ablations and was disease free at 40-month follow-up.

Conclusions

Thermal ablation effectively treated or controlled stage IA NSCLC in medically inoperable patients. Three-year OS exceeded 50%, and LP did not affect OS. Therefore, thermal ablation is a viable option for medically inoperable patients with early stage NSCLC.

Model-based optimal planning of hepatic radiofrequency ablation

This article presents a model-based pre-treatment optimal planning framework for hepatic tumour radiofrequency (RF) ablation. Conventional hepatic radiofrequency (RF) ablation methods rely on pre-specified input voltage and treatment length based on the tumour size. Using these experimentally obtained pre-specified treatment parameters in RF ablation is not optimal to achieve the expected level of cell death and usually results in more healthy tissue damage than desired. In this study we present a pre-treatment planning framework that provides tools to control the levels of both the healthy tissue preservation and tumour cell death. Over the geometry of tumour and surrounding tissue, we formulate the RF ablation planning as a constrained optimization problem. With specific constraints over the temperature profile (TP) in pre-determined areas of the target geometry, we consider two different cost functions based on the history of the TP and Arrhenius index (AI) of the target location, respectively. We optimally compute the input voltage variation to minimize the damage to the healthy tissue while ensuring a complete cell death in the tumour and immediate area covering the tumour. As an example, we use a simulation of a 1D symmetric target geometry mimicking the application of single electrode RF probe. Results demonstrate that compared to the conventional methods both cost functions improve the healthy tissue preservation.

Radiofrequency Ablation of Liver Metastases from Colorectal Carcinoma

BACKGROUND

Most patients with colorectal carcinoma will develop liver metastases. Radiofrequency ablation (RFA) has been utilized in metastatic CRC to help improve the survival gap between resectable and unresectable tumor.

METHODS

The current use of RFA in selected patient populations is reviewed.

RESULTS

RFA provides a survival benefit in patients with unresectable hepatic metastases from CRC compared with chemotherapy alone. It offers effective local tumor destruction in appropriately selected lesions and minimizes the morbidity and mortality of an open resection. Common complications are abdominal bleeding (1.6%), abdominal infection (1.1%), and injury to the biliary tree (1.0%). Mortality ranges from 0% to 0.5%.

CONCLUSIONS

Trials are underway to compare chemotherapy plus local ablation to chemotherapy alone. RFA is a tool that should be utilized by experienced individuals to achieve optimal oncologic outcomes.