High operative risk of cool-tip radiofrequency ablation for unresectable pancreatic head cancer

Irreversible Electroporation

Irreversible electroporation (IRE) is a predominantly nonthermal ablative technology that uses high-voltage, low-energy DC current pulses to induce cell death. Thermal ablative technologies such as radiofrequency ablation, microwave ablation, and cryoablation have several applications in oncology but have limitations that have been established. IRE has shown promise to overcome some of these limitations. This article reviews the basics of the technology, patient selection, clinical applications, practical pointers, and the published data.

Minimally Invasive Techniques for Resection of Pancreatic Neuroendocrine Tumors

Surgical resection remains the treatment of choice for primary pancreatic neuroendocrine tumors (PNETs), because it is associated with increased survival. Minimally invasive procedures are a safe modality for the surgical treatment of PNETs. In malignant PNETs, laparoscopy is not associated with a compromise in terms of oncologic resection, and provides the benefits of decreased postoperative pain, better cosmetic results, shorter hospital stay, and a shorter postoperative recovery period. Further prospective, multicenter, randomized trials are required for the analysis of these minimally invasive surgical techniques for the treatment of PNETs and their comparison with traditional open pancreatic surgery.

Irreversible electroporation of the pancreas is feasible and safe in a porcine survival model

OBJECTIVES

Use of thermal tumor ablation in the pancreatic parenchyma is limited because of the risk of pancreatitis, pancreatic fistula, or hemorrhage. This study aimed to evaluate the feasibility and safety of irreversible electroporation (IRE) in a porcine model.

METHODS

Ten pigs were divided into 2 study groups. In the first group, animals received IRE of the pancreatic tail and were killed after 60 minutes. In the second group, animals received IRE at the head of the pancreas and were followed up for 7 days. Clinical parameters, computed tomography imaging, laboratory results, and histology were obtained.

RESULTS

All animals survived IRE ablation, and no cardiac adverse effects were noted. Sixty minutes after IRE, a hypodense lesion on computed tomography imaging indicated the ablation zone. None of the animals developed clinical signs of acute pancreatitis. Only small amounts of ascites fluid, with a transient increase in amylase and lipase levels, were observed, indicating that no pancreatic fistula occurred.

CONCLUSIONS

This porcine model shows that IRE is feasible and safe in the pancreatic parenchyma. Computed tomography imaging reveals significant changes at 60 minutes after IRE and therefore might serve as an early indicator of therapeutic success. Clinical studies are needed to evaluate the efficacy of IRE in pancreatic cancer.

Radiofrequency Ablation of the Pancreas: Protective Effect of Local Cooling Techniques

Pancreatic carcinoma is one of the commonest malignant diseases today and the majority of patients are suitable for palliative treatment only. Radiofrequency ablation (RFA) has been used extensively for the treatment of solid organ tumors but little is known on the efficacy and safety of pancreatic ablation. To further investigate the safety of pancreatic RFA, 18 pigs had RFA of the pancreas, close to superior mesenteric vein and duodenum. Group A (nine animals) was protected with peripancreatic cool perfusion and Group B (nine animals) with portal vein (PV) intravenous injection of cool saline. Biochemical and histological evidence suggested lateral thermal injury of the duodenal wall and superior mesenteric vein and acute pancreatitis in most animals. However, clinically and at autopsy, Group B animals fared much better. PV thrombosis, hepatic abscess, duodenal perforation, ascites, and extensive pancreatic necrosis were observed in Group A but not in Group B. The present study suggests that PV cool saline perfusion can prevent major complications caused by pancreatic RFA and may be used in combination with other protective techniques in the clinical setting to reduce RFA-associated morbidity.

Endoscopic ultrasound guided radiofrequency ablation, for pancreatic cystic neoplasms and neuroendocrine tumors

AIM

To outline the feasibility, safety, adverse events and early results of endoscopic ultrasound (EUS)-radiofrequency ablation (RFA) in pancreatic neoplasms using a novel probe.

METHODS

This is a multi-center, pilot safety feasibility study. The intervention described was radiofrequency ablation (RF) which was applied with an innovative monopolar RF probe (1.2 mm Habib EUS-RFA catheter) placed through a 19 or 22 gauge fine needle aspiration (FNA) needle once FNA was performed in patients with a tumor in the head of the pancreas. The Habib™ EUS-RFA is a 1 Fr wire (0.33 mm, 0.013") with a working length of 190 cm, which can be inserted through the biopsy channel of an echoendoscope. RF power is applied to the electrode at the end of the wire to coagulate tissue in the liver and pancreas.

RESULTS

Eight patients [median age of 65 (range 27-82) years; 7 female and 1 male] were recruited in a prospective multicenter trial. Six had a pancreatic cystic neoplasm (four a mucinous cyst, one had intraductal papillary mucinous neoplasm and one a microcystic adenoma) and two had a neuroendocrine tumors (NET) in the head of pancreas. The mean size of the cystic neoplasm and NET were 36.5 mm (SD ± 17.9 mm) and 27.5 mm (SD ± 17.7 mm) respectively. The EUS-RFA was successfully completed in all cases. Among the 6 patients with a cystic neoplasm, post procedure imaging in 3-6 mo showed complete resolution of the cysts in 2 cases, whilst in three more there was a 48.4% reduction [mean pre RF 38.8 mm (SD ± 21.7 mm) vs mean post RF 20 mm (SD ± 17.1 mm)] in size. In regards to the NET patients, there was a change in vascularity and central necrosis after EUS-RFA. No major complications were observed within 48 h of the procedure. Two patients had mild abdominal pain that resolved within 3 d.

CONCLUSION

EUS-RFA of pancreatic neoplasms with a novel monopolar RF probe was well tolerated in all cases. Our preliminary data suggest that the procedure is straightforward and safe. The response ranged from complete resolution to a 50% reduction in size.

Systematic review of innovative ablative therapies for the treatment of locally advanced pancreatic cancer

BACKGROUND

Locally advanced pancreatic cancer (LAPC) is associated with a very poor prognosis. Current palliative (radio)chemotherapy provides only a marginal survival benefit of 2-3 months. Several innovative local ablative therapies have been explored as new treatment options. This systematic review aims to provide an overview of the clinical outcomes of these ablative therapies.

METHODS

A systematic search in PubMed, Embase and the Cochrane Library was performed to identify clinical studies, published before 1 June 2014, involving ablative therapies in LAPC. Outcomes of interest were safety, survival, quality of life and pain.

RESULTS

After screening 1037 articles, 38 clinical studies involving 1164 patients with LAPC, treated with ablative therapies, were included. These studies concerned radiofrequency ablation (RFA) (7 studies), irreversible electroporation (IRE) (4), stereotactic body radiation therapy (SBRT) (16), high-intensity focused ultrasound (HIFU) (5), iodine-125 (2), iodine-125-cryosurgery (2), photodynamic therapy (1) and microwave ablation (1). All strategies appeared to be feasible and safe. Outcomes for postoperative, procedure-related morbidity and mortality were reported only for RFA (4-22 and 0-11 per cent respectively), IRE (9-15 and 0-4 per cent) and SBRT (0-25 and 0 per cent). Median survival of up to 25·6, 20·2, 24·0 and 12·6 months was reported for RFA, IRE, SBRT and HIFU respectively. Pain relief was demonstrated for RFA, IRE, SBRT and HIFU. Quality-of-life outcomes were reported only for SBRT, and showed promising results.

CONCLUSION

Ablative therapies in patients with LAPC appear to be feasible and safe.

Radio frequency radiation-induced hyperthermia using Si nanoparticle-based sensitizers for mild cancer therapy

Offering mild, non-invasive and deep cancer therapy modality, radio frequency (RF) radiation-induced hyperthermia lacks for efficient biodegradable RF sensitizers to selectively target cancer cells and thus avoid side effects. Here, we assess crystalline silicon (Si) based nanomaterials as sensitizers for the RF-induced therapy. Using nanoparticles produced by mechanical grinding of porous silicon and ultraclean laser-ablative synthesis, we report efficient RF-induced heating of aqueous suspensions of the nanoparticles to temperatures above 45-50 °C under relatively low nanoparticle concentrations (<1 mg/mL) and RF radiation intensities (1-5 W/cm(2)). For both types of nanoparticles the heating rate was linearly dependent on nanoparticle concentration, while laser-ablated nanoparticles demonstrated a remarkably higher heating rate than porous silicon-based ones for the whole range of the used concentrations from 0.01 to 0.4 mg/mL. The observed effect is explained by the Joule heating due to the generation of electrical currents at the nanoparticle/water interface. Profiting from the nanoparticle-based hyperthermia, we demonstrate an efficient treatment of Lewis lung carcinoma in vivo. Combined with the possibility of involvement of parallel imaging and treatment channels based on unique optical properties of Si-based nanomaterials, the proposed method promises a new landmark in the development of new modalities for mild cancer therapy.

Intraductal radiofrequency ablation for management of malignant biliary obstruction

Self-expandable metal stents (SEMS) are the current standard of care for the palliative management of malignant biliary strictures. Recently, endoscopic ablative techniques with direct affect to local tumor have been developed to improve SEMS patency. Several reports have demonstrated the technical feasibility and safety of intraductal radiofrequency ablation (RFA), by both endoscopic and percutaneous approaches, in palliation of malignant strictures of the bile duct. Intraductal RFA has also been used in the treatment of occlusion of both covered and uncovered SEMS occlusion from tumor ingrowth or overgrowth. This article provides a comprehensive review of intraductal RFA in the management of malignant biliary obstruction.

Cryosurgery for pancreatic cancer

The procedure of pancreatic cryosurgery is performed with intraoperative or percutaneous approaches. Based on current data and our initial experience, cryoablation appears to be a feasible, potentially safe and promising option in patients with locally advanced and unresectable pancreatic cancer. It is suggested that there are almost no known contraindications to the use of cryosurgery for pancreatic cancer. For most patients with pancreatic cancer, cryosurgery can substitute conventional surgery.

Radiofrequency ablation of pancreatic neuroendocrine tumors: a pilot study of feasibility, efficacy, and safety

OBJECTIVE

This study aimed to assess the feasibility, safety, and efficacy of radiofrequency ablation (RFA) of pancreatic neuroendocrine tumors (PNETs).

METHODS

We performed RFA on 10 patients (7 women) aged 38 to 75 years with histologically diagnosed PNETs (secreting in 3 cases) who could not or would not undergo surgical resection. Tumor nodules (diameter, 0.9-2.9 cm; mean [SD], 1.6 [0.5] cm) were located in the head (n = 7) or body (n = 3) of the pancreas. Ultrasound-guided RFA was performed percutaneously (n = 7), endoscopically (n = 1), or intraoperatively (n = 2) using commercially available equipment. Complete ablation was defined as absence of enhancing tissue at the tumor site on contrast-enhanced imaging studies and normalization of previously elevated serum hormone levels.

RESULTS

Complete ablation was achieved with 1 (n = 9) or 2 (n = 1) RFA procedures. All neuroendocrine syndromes regressed within 24 hours of treatment. No recurrences were observed during follow-up (range, 12-60 months; median [SD], 34 [14] months). No deaths occurred. Major complications included acute pancreatitis in 3 patients, 2 of whom developed pancreatic fluid collections that were successfully managed with ultrasound-guided drainage and endoscopy.

CONCLUSIONS

Radiofrequency ablation is a feasible, safe, and effective option for patients with small PNETs who cannot or do not want to undergo surgical resection.

Radiofrequency pancreatic ablation and section of the main pancreatic duct does not lead to necrotizing pancreatitis

OBJECTIVE

The aim of this study was to determine whether radiofrequency ablation (RFA) of the pancreas and subsequent transection of the main pancreatic duct may avoid the risk of both necrotizing pancreatitis and postoperative pancreatic fistula (POPF) formation.

METHODS

Thirty-two rats were subjected to RFA and section of the pancreas over their portal vein. Animals were killed at 3, 7, 15, and 21 days (groups 0-3, respectively). Two additional control groups (sham operation and user manipulation only, respectively) of 15 days of postoperative period were considered. Postoperative complications, histological changes (including morphometric and immunohistochemical analysis), and incidence of POPF were evaluated.

RESULTS

A significant increase in serum amylase levels (P < 0.05) on the third postoperative day, which return to baseline levels in the following weeks, was noted in groups 0 to 3. Those groups showed a rapid atrophy of the distal pancreas by apoptosis with no signs of necrotizing pancreatitis or POPF. The distal pancreas in groups 1 to 3 compared with group 0 and control groups showed a significant increase of small islets (<1000 µm).

CONCLUSIONS

The rapid acinar atrophy of the distal pancreas after RFA and section of the pancreatic ducts in this model does not lead to necrotizing pancreatitis.

Microwave ablation of pancreatic head cancer: safety and efficacy

PURPOSE

To evaluate the safety and efficacy of percutaneous microwave (MW) ablation treatment in locally advanced, nonresectable, nonmetastatic pancreatic head cancer.

MATERIALS AND METHODS

Ten patients with pancreatic head cancer treated with percutaneous (n = 5) or laparotomic (n = 5) MW ablation were retrospectively reviewed. The MW generator used (45 W at 915 MHz) was connected by coaxial cable to 14-gauge straight MW antennas with a 3.7- or 2-cm radiating section. One or two antennae were used, with an ablation time of 10 minutes. Ultrasonographic (US) and combined US/cone-beam computed tomographic (CT) guidance were used in five patients each. Follow-up was performed by CT after 1, 3, 6, and, when possible, 12 months. Tumor response was assessed per Response Evaluation Criteria In Solid Tumors (version 1.1) and Choi criteria. The feasibility, safety, and major and minor complications associated with quality of life (QOL) were recorded prospectively.

RESULTS

The procedure was feasible in all patients (100%). One late major complication was observed in one patient, and no visceral injury was detected. No patient had further surgery, and all minor complications resolved during the hospital stay. An improvement in QOL was observed in all patients despite a tendency to return to preoperative levels in the months following the procedure, without the influence of minor complications. No repeat treatment was performed.

CONCLUSIONS

Despite the small number of patients, the present results can be considered encouraging, showing that MW ablation is a feasible approach in the palliative treatment of pancreatic tumors.

Systematic review of novel ablative methods in locally advanced pancreatic cancer

Unresectable locally advanced pancreatic cancer with or without metastatic disease is associated with a very poor prognosis. Current standard therapy is limited to chemotherapy or chemoradiotherapy. Few regimens have been shown to have a substantial survival advantage and novel treatment strategies are urgently needed. Thermal and laser based ablative techniques are widely used in many solid organ malignancies. Initial studies in the pancreas were associated with significant morbidity and mortality, which limited widespread adoption. Modifications to the various applications, in particular combining the techniques with high quality imaging such as computed tomography and intraoperative or endoscopic ultrasound has enabled real time treatment monitoring and significant improvements in safety. We conducted a systematic review of the literature up to October 2013. Initial studies suggest that ablative therapies may confer an additional survival benefit over best supportive care but randomised studies are required to validate these findings.

Radiofrequency ablation for unresectable locally advanced pancreatic cancer: a systematic review

BACKGROUND

Median survival in patients with unresectable locally advanced pancreatic cancer lies in the range of 9-15 months. Radiofrequency ablation (RFA) may prolong survival, but data on its safety and efficacy are scarce.

METHODS

A systematic literature search was performed in PubMed, EMBASE and the Cochrane Library with the syntax '(radiofrequency OR RFA) AND (pancreas OR pancreatic)' for studies published until 1 January 2012. In addition, a search of the proceedings of conferences on pancreatic disease that took place during 2009-2011 was performed. Studies with fewer than five patients were excluded as they were considered to be case reports. The primary endpoint was survival. Secondary endpoints included morbidity and mortality.

RESULTS

Five studies involving a total of 158 patients with pancreatic cancer treated with RFA fulfilled the eligibility criteria. These studies reported median survival after RFA of 3-33 months, morbidity related to RFA of 4-37%, mortality of 0-19% and overall morbidity of 10-43%. Pooling of data was not appropriate as the study populations and reported outcomes were heterogeneous. Crucial safety aspects included ensuring a maximum RFA tip temperature of < 90 °C and ensuring minimum distances between the RFA probe and surrounding structures.

CONCLUSIONS

Radiofrequency ablation seems to be feasible and safe when it is used with the correct temperature and at an appropriate distance from vital structures. It appears to have a positive impact on survival. Multicentre randomized trials are necessary to determine the true effect size of RFA and to minimize the impacts of selection and publication biases.

Role of endoscopic ultrasound in treatment of pancreatic cancer

Endoscopic ultrasound (EUS) can help diagnose diseases with high accuracy because it overcomes the limitations of gastrointestinal gas and abdominal fat. The emergence of curved linear-array echoendoscopy has significantly promoted the applications of the technique to new levels. The advancement has appeared from EUS imaging to EUS-guided fine needle aspiration, drainage and injection. Computed tomography and magnetic resonance imaging present certain limitations for diagnosing pancreatic tumors due to the specificity of the location of such growths. In addition, traditional chemotherapy does not show ideal results because pancreatic cancer (PC) exhibits hypovascular characteristics. Interventional EUS can overcome these limitations and has potential to become the mainstream method of PC local treatment in the future. This paper reviews the use of interventional EUS in the treatment of PC based on previous studies.

Minimally invasive ablation treatment for locally advanced pancreatic adenocarcinoma

Pancreatic adenocarcinoma is an aggressive tumour with an extremely poor prognosis, which has not changed significantly during the last 30 years. Prolonged survival is achieved only by R0 resection with macroscopic tumour clearance. However, the majority of the cases are considered inoperable at diagnosis due to local spread or presence of metastatic disease. Chemoradiotherapy is not tolerated by all patients and still fails to prolong survival significantly; neoadjuvant treatment also has limited results on pain control or tumour downstaging. In recent years, there has been a growing interest in the use of ablation therapy for the treatment of nonresectable tumours in various organs. Ablation techniques are based on direct application of chemical, thermal, or electrical energy to a tumour, which leads to cellular necrosis. With ablation, tumour cytoreduction, local control, and relief from symptoms are obtained in the majority of the patients. Inoperable cases of pancreatic adenocarcinoma have been treated by various ablation techniques in the last few years with promising results. The purpose of this review is to present the current status of local ablative therapies in the treatment of pancreatic adenocarcinoma and to investigate on the efficiency and the future trends.

Interventional radiology and the pancreatic cancer patient

Patients with pancreatic cancer have a dismal prognosis. This article reviews the role that interventional radiology can play in managing postoperative complications and in patient palliation, particularly with an obstructed biliary system. In addition, options for cytoreduction are discussed, including chemoembolization, radioembolization, and thermal ablation. The final option reviewed is irreversible electroporation, which is being explored as a technique to allow patients with locally advanced pancreatic cancer to be converted to surgical candidates.

Percutaneous irreversible electroporation for downstaging and control of unresectable pancreatic adenocarcinoma

PURPOSE

Treatment of unresectable locally advanced pancreatic cancer (LAPC) usually includes chemotherapy and/or radiation therapy in an attempt to downstage these tumors to the extent of resectability, but outcomes remain poor. Irreversible electroporation (IRE) is an ablative modality that may be useful in this population. The aim of this study was to evaluate the safety of percutaneous IRE in patients with pancreatic adenocarcinoma.

MATERIALS AND METHODS

IRE was performed in patients with pancreatic cancer whose tumors remained unresectable after, or who were intolerant of, standard therapy. The procedures were all done percutaneously under general anesthesia. Patients were then followed for adverse events, tumor response, and survival.

RESULTS

Fifteen IRE procedures were performed in 14 patients (one was treated twice). Three patients had metastatic disease and 11 had LAPC. All patients had received chemotherapy previously, and 11 had received radiation. The median tumor size was 3.3 cm (range, 2.5-7 cm). Immediate and 24-hour postprocedural scans demonstrated patent vasculature in the treatment zone in all patients. Two patients underwent surgery 4 and 5 months after IRE, respectively. Both had margin-negative resections, and one had a pathologic complete response; both remain disease-free after 11 and 14 months, respectively. Complications included spontaneous pneumothorax during anesthesia (n = 1) and pancreatitis (n = 1), and both patients recovered completely. There were no deaths directly related to the procedure. All three patients with metastatic disease at IRE died from progression of their disease.

CONCLUSIONS

Percutaneous IRE for pancreatic adenocarcinoma is feasible and safe. A prospective trial is being planned.

Radiofrequency ablation of the pancreas with and without intraluminal duodenal cooling in a porcine model

OBJECTIVE

To determine the short-term outcome of radiofrequency ablation (RFA) of pancreatic tissue near the duodenum and portomesenteric vessels (PMV) in a porcine model with and without intraluminal duodenal cooling.

BACKGROUND

RFA has been proposed as a new treatment strategy in patients with unresectable locally advanced pancreatic cancer. RFA may cause thermal damage to the duodenum and vascular structures, but these risks and potential protective measures have never been systematically addressed. Intraluminal duodenal cooling during RFA could prevent thermal damage to the duodenum.

METHODS

RFA was performed in 11 pigs during laparotomy with a bipolar probe of 30 mm active length at a power of 30 W until a total energy of 15 kJ was administered. The RFA probe was inserted in the pancreas at 5 or 15 mm from the duodenum, PMV, and in the pancreatic tail. RFA near the duodenum was performed with and without intraluminal duodenal cooling using 100 mL/min saline of 5°C. Histopathologic assessment was performed.

RESULTS

The maximum RFA-induced temperature was 92°C. RFA with one single probe induced adequate ablation lesions with a diameter of 20 mm over a length of 30 mm. Without duodenal cooling, RFA induced duodenal thermal damage, whereas with duodenal cooling, no damage was observed. RFA at 15 mm from the PMV resulted in minimal superficial focal vascular damage, without thrombosis or hemorrhage.

CONCLUSIONS

RFA provides adequate ablation zones in the pancreas of the porcine. Thermal damage to the duodenum can be prevented by intraluminal duodenal cooling without loss of ablation effectivity.

Tumors and new endoscopic ultrasound-guided therapies

With the advent of linear echoendoscopes, endoscopic ultrasound (EUS) has become more operative and a new field of oncological application has been opened up. From tumor staging to tissue acquisition under EUS-guided fine-needle aspiration, new operative procedures have been developed on the principle of the EUS-guided puncture. A hybrid probe combining radiofrequency with cryotechnology is now available, to be passed through the operative channel of the echoendoscope into the tumor to create an area of ablation. EUS-guided fine-needle injection is emerging as a method to deliver anti-tumoral agents inside the tumor. Ethanol lavage, with or without paclitaxel, has been proposed for the treatment of cystic tumors in non-resectable cases and complete resolution has been recorded in up to 70%-80%. Many other chemical or biological agents have been investigated for the treatment of pancreatic adenocarcinoma: activated allogenic lymphocyte culture (Cytoimplant), a replication-deficient adenovirus vector carrying the tumor necrosis factor-α gene, or an oncolytic attenuated adenovirus (ONYX-015). The potential advantage of treatment under EUS control is the real-time imaging guidance into a deep target like the pancreas which is extremely difficult to reach by a percutaneous approach. To date there are no randomized controlled trials to confirm the real clinical benefits of these treatments compared to standard therapy so it seems wise to reserve them only for experimental protocols approved by ethics committees.

Radiofrequency ablation for liver metastasis from gastric cancer

AIMS

Several studies have reported the benefit of hepatic resection for metastatic tumor from gastric cancer. However, the value of treatment with radiofrequency ablation (RFA) has not been clearly defined.

METHODS

Between Jan 2002 and Dec 2007, 21 patients with primary gastric cancer were diagnosed with synchronous or metachronous liver metastases. All patients were treated with RFA, and the complication, survival, and recurrence rates were assessed.

RESULTS

The postoperative complication rate was 5% (1/21), with no mortality. The median actuarial survival time was 14 months. The 1-yr, 2-yr, 3-yr, and 5-yr survival rates after RFA were 70%, 11%, 5%, and 3%, respectively. With a median follow-up time of 19 months, local recurrence at the RFA site was 19% (4/21). Solitary metastasis had significantly longer survival than multiple lesions after RFA (22 vs 10 months, P = 0.004).

CONCLUSIONS

RFA provides a minimally invasive and safe modality of treatment patients with liver metastasis from gastric cancer. Patients with solitary liver lesion were considered appropriate candidates for RFA.

Feasibility and safety of EUS-guided cryothermal ablation in patients with locally advanced pancreatic cancer

BACKGROUND

New therapies are needed for pancreatic cancer.

OBJECTIVE

To determine the feasibility and safety of a new endoscopic treatment. Secondary endpoints were to determine effects on tumor growth measured with CT scan and to find the overall survival.

DESIGN

A cohort study of patients with local progression of advanced pancreatic adenocarcinoma after neoadjuvant therapy. The cryotherm probe (CTP), a flexible bipolar device that combines radiofrequency with cryogenic cooling, was used under EUS guidance.

SETTING

San Raffaele Hospital, Milan, Italy; University Medical Center, Hamburg-Eppendorf, Germany.

PATIENTS

A total of 22 patients (male/female 11/11; mean age 61.9 years) were enrolled from September 2009 to May 2011.

INTERVENTION

Radiofrequency heating: 18 W; pressure for cooling: 650 psi (Pounds per Square Inch); application time: depending on tumor size.

MAIN OUTCOME MEASUREMENTS

Feasibility was evaluated during the procedure. A clinical and radiologic follow-up was planned.

RESULTS

The CTP was successfully applied in 16 patients (72.8%); in 6 it was not possible because of stiffness of the GI wall and of the tumor. Amylase arose in 3 of 16 patients; none had clinical signs of pancreatitis. Late complications arose in 4 cases: 3 were mostly related to tumor progression. Median postablation survival time was 6 months. A CT scan was performed in all patients, but only in 6 of 16 was it possible to clearly define the tumor margins after ablation. In these patients, the tumor appeared smaller compared with the initial mass (P = .07).

LIMITATIONS

Small sample of patients, difficulty of objectifying the size of the ablated zone by CT scan.

CONCLUSION

EUS-guided CTP ablation is feasible and safe. Further investigations are needed to demonstrate progression-free survival and local control.

Endoscopic Ultrasound-Guided Radiofrequency Ablation (EUS-RFA) of the Pancreas in a Porcine Model

Backgrounds. Limited effective palliative treatments exist for pancreatic cancer which includes surgery or chemotherapy. Radiofrequency ablation (RFA) uses high frequency alternating current to ablate diseased tissue and has been used to treat various tumors. In this study, we evaluated a prototype probe adjusted to the EUS-needle to perform EUS-RFA to permit coagulative necrosis in the pancreas. Methods. Five Yucatan pigs underwent EUS-guided radiofrequency ablation of the head of their pancreas. Using an EUS-needle, RFA was applied with 6 mm and then 10 mm of the probe exposed at specific wattage for preset durations. Results. Only one pig showed moderate levels of pancreatitis (20% proximal pancreatitis). The other animals showed much lower areas of tissue damage. In 3 of the 5 pigs, the proximal pancreas showed greater levels of tissue injury than the distal pancreas, consistent with the proximity of the tissue to the procedure site. In 1 pig, both proximal and distal pancreas showed minimal pancreatitis (1%). There was minimal evidence of fat necrosis in intra-pancreatic and/or extra-pancreatic adipose tissue. Conclusion. EUS-guided RFA of the pancreatic head with the monopolar probe through a 19-gauge needle was well tolerated in 5 Yucatan pigs and with minimal amount of pancreatitis.

Pancreatic metastases from renal cell carcinoma: the state of the art

Pancreatic metastases are rare, with a reported incidence varying from 1.6% to 11% in autopsy studies of patients with advanced malignancy. In clinical series, the frequency of pancreatic metastases ranges from 2% to 5% of all pancreatic malignant tumors. However, the pancreas is an elective site for metastases from carcinoma of the kidney and this peculiarity has been reported by several studies. The epidemiology, clinical presentation, and treatment of pancreatic metastases from renal cell carcinoma are known from single-institution case reports and literature reviews. There is currently very limited experience with the surgical resection of isolated pancreatic metastasis, and the role of surgery in the management of these patients has not been clearly defined. In fact, for many years pancreatic resections were associated with high rates of morbidity and mortality, and metastatic disease to the pancreas was considered to be a terminal-stage condition. More recently, a significant reduction in the operative risk following major pancreatic surgery has been demonstrated, thus extending the indication for these operations to patients with metastatic disease.

Interventional endoscopic ultrasonography: present and future

The technical advances in endoscopic ultrasonograpy (EUS) and accessories have enabled performing EUS-guided intervention in the pancreas and biliary tract. Many research centers have been performing or investigating EUS-guided drainage, EUS-guided celiac plexus neurolysis and block, EUS-guided anastomosis that includes choledocho-enterostomy and choledocho-gastrostomy, EUS-guided ablation and injection therapy mainly for pancreatic neoplasm, EUS-guided photodynamic therapy and EUS-guided brachytherapy. Some of these are currently clinical applications and others are under investigations in clinical studies or animal models. Further detailed randomized controlled clinical trials and the development of materials will bring us into a new era of therapeutic EUS.

Interventional endoscopic ultrasonography: present and future

The technical advances in endoscopic ultrasonograpy (EUS) and accessories have enabled performing EUS-guided intervention in the pancreas and biliary tract. Many research centers have been performing or investigating EUS-guided drainage, EUS-guided celiac plexus neurolysis and block, EUS-guided anastomosis that includes choledocho-enterostomy and choledocho-gastrostomy, EUS-guided ablation and injection therapy mainly for pancreatic neoplasm, EUS-guided photodynamic therapy and EUS-guided brachytherapy. Some of these are currently clinical applications and others are under investigations in clinical studies or animal models. Further detailed randomized controlled clinical trials and the development of materials will bring us into a new era of therapeutic EUS.

EUS-guided Nd:YAG laser ablation of normal pancreatic tissue: a pilot study in a pig model

BACKGROUND

Laser ablation with a neodymium:yttrium aluminum garnet (Nd:YAG) laser can achieve a high rate of complete tissue necrosis and has been applied as a minimally invasive, palliative option in hepatocellular carcinoma, liver metastasis in colorectal cancer, and malignant thyroid nodules.

OBJECTIVE

To assess the in vivo feasibility of EUS-guided laser ablation with an Nd:YAG laser of normal pancreatic tissue of a porcine model.

DESIGN

Prospective investigation.

SETTING

Hospital animal laboratory.

SUBJECTS

Eight pigs.

INTERVENTIONS

EUS-guided puncture of the pancreatic tail with a laser-beam fiber. An Nd:YAG laser (1.064 nm) was used, with an output power of 2 and 3 W and a total delivered energy of 500 and 1000 J in continuous mode.

MAIN OUTCOME MEASUREMENTS

The 24-hour follow-up of the pigs was focused on clinical and laboratory aspects. Results of histological studies of the pancreas were obtained 24 hours after the procedure on necroscopy tissue.

RESULTS

There were no technical limitations to the performance of the procedure. Tissue necrosis, localized in the pancreatic parenchyma, was observed in all animals on histological examination. The volume of ablation tissue ranged from a mean of 314 mm(3) to 483 mm(3). The ablation area ranged from a mean of 49 mm(2) to 80 mm(2). No major postprocedure complications were recorded, and all the pigs survived at 24 hours.

LIMITATION

Animal study.

CONCLUSIONS

EUS-guided laser ablation of the pancreas with an Nd:YAG laser is feasible in a porcine model.

Radiofrequency ablation of locally advanced pancreatic adenocarcinoma: an overview

Radiofrequency ablation (RFA) of pancreatic neoplasms is restricted to locally advanced, non-resectable but non-metastatic tumors. RFA of pancreatic tumors is nowadays an ultrasound-guided procedure performed during laparotomy in open surgery. Intraoperative ultrasound covers the mandatory role of staging, evaluation of feasibility, guidance and monitoring of the procedure. Different types of needle can be used. The first aim in the evaluation of RFA as a treatment for locally advanced pancreatic ductal adenocarcinoma, in order of evaluation but not of importance, is to determine the feasibility of the procedure. The second aim is to establish the effect of RFA on tumoral mass in terms of necrosis and cytoreduction. The most important aim, third in order of evaluation, is the potential improvement of quality of life and survival rate. Nowadays, only a few studies assess the feasibility of the procedure. The present paper is an overview of RFA for pancreatic adenocarcinoma.

Pancreatic carcinoma cells are susceptible to noninvasive radio frequency fields after treatment with targeted gold nanoparticles

BACKGROUND

Gold and carbon nanoparticles absorb nonionizing radio frequency (RF) energy and release heat. Solid gold nanoparticles are delivered to cancer cells via conjugation with targeting antibodies. Here, 20-nm gold particles were conjugated to cetuximab, which is an epidermal growth factor receptor-1 (EGFR-1) antibody.

METHODS

A pancreatic carcinoma cell line that highly expresses EGFR-1, Panc-1, and Cama-1, which is a breast carcinoma cell line that minimally expresses EGFR-1, were treated with 100-nmol/L cetuximab-conjugated gold nanoparticles for 3 h (n = 4). Thirty-six hours later, the dishes were placed in an RF field with a generator power of 200 W for 5 min. After another 36 h, cell injury and death were evaluated with flow cytometry.

RESULTS

The targeted cell line Panc-1 had a viability of 46% +/- 12%, whereas the Cama-1 cell had a viability of 92% +/- 2% after RF field exposure (P < .008). Transmission electron microscopy showed gold nanoparticle uptake in Panc-1 cells but negligible uptake by Cama-1 cells. Nontargeted cells do not internalize a sufficient amount of antibody-conjugated gold nanoparticles to induce injury in a noninvasive RF field.

CONCLUSION

This technique could be useful in cancer treatment if a cancer-specific antibody is used to localize gold nanoparticles to malignant cells.

US-guided application of a new hybrid probe in human pancreatic adenocarcinoma: an ex vivo study

BACKGROUND

Ablative therapies such as radiofrequency and cryotechnology are widely used in oncological intervention but not in the pancreatic field because of their high operative risks. A new flexible bipolar ablation device (Cryotherm probe [CTP]) was developed combining radiofrequency and cryotechnology.

OBJECTIVE

To evaluate the efficacy of the CTP in destroying neoplastic tissue of explanted pancreatic tumors of patients with pancreatic adenocarcinoma.

DESIGN

Ex vivo clinical study.

SETTING

Inpatient hospital setting.

PATIENTS

This study involved 16 explanted pancreatic tumors from 16 patients.

INTERVENTIONS

CTP application was performed on explanted pancreatic tumors. Anatomic specimens were divided into 4 groups; each group received a predefined application time of 120 to 600 seconds.

MAIN OUTCOME MEASUREMENTS

The coagulation diameter (short axis) perpendicular to the device's longitudinal axis was used as the primary outcome measure.

RESULTS

All pancreatic specimens showed histological signs of coagulative necrosis. There was a positive correlation between the short axis of the obtained necrosis and duration of application (r = 0.74).

LIMITATIONS

This study was an ex vivo study with all limitations typical of this kind of study.

CONCLUSIONS

The CTP is effective in destroying neoplastic pancreatic tissue, creating an ablation zone, the extent of which is related to the duration of application.

Feasibility and safety of radiofrequency ablation for locally advanced pancreatic cancer

BACKGROUND

: Radiofrequency ablation (RFA) may be a valuable treatment option for locally advanced pancreatic cancer. The present study examined its feasibility and safety.

METHODS

: Fifty patients with locally advanced pancreatic cancer were studied prospectively. Ultrasound-guided RFA was performed during laparotomy. The main outcome measures were short-term morbidity and mortality.

RESULTS

: The tumour was located in the pancreatic head or uncinate process in 34 patients and in the body or tail in 16; median diameter was 40 (interquartile range 30-50) mm. RFA was the only treatment in 19 patients. RFA was combined with biliary and gastric bypass in 19 patients, gastric bypass alone in eight, biliary bypass alone in three and pancreaticojejunostomy in one. The 30-day mortality rate was 2 per cent. Abdominal complications occurred in 24 per cent of patients; in half they were directly associated with RFA and treated conservatively. Three patients with surgery-related complications needed reoperation. Reduction of RFA temperature from 105 degrees C to 90 degrees C resulted in a significant reduction in complications (ten versus two of 25 patients; P = 0.028). Median postoperative hospital stay was 10 (range 7-31) days.

CONCLUSION

: RFA of locally advanced pancreatic cancer is feasible and relatively well tolerated, with a 24 per cent complication rate.

Interventional endoscopic ultrasound: the next frontier in gastrointestinal endoscopy

Endoscopic ultrasound (EUS) has become well established as a diagnostic modality in gastrointestinal cancer staging. It offers high-resolution imaging and fine-needle biopsy, which is essential in tumor and nodal staging of gastrointestinal cancers. In the recent decade, however, many therapeutic applications of EUS have become possible. Currently, interventional EUS endoscopy involves celiac plexus neurolysis, pseudocyst drainage, and intratumoral fine-needle injection therapy for inoperable pancreatic malignancy. Emerging techniques include the accurate endoscopic delivery of radioactive beads to localize tumor therapy as well as other therapies, such as radiofrequency ablation or cryotherapy. Diagnostic and therapeutic access to the biliary tree and pancreatic duct is increasingly being used successfully in failed endoscopic retrograde cholangiopancreatography (ERCP) procedures. This review discusses these procedures and several evolving future applications, including vascular access and EUS-guided enteral anastomosis.

Radiofrequency ablation of a pancreatic metastasis from renal cell carcinoma: case report

INTRODUCTION

There is little reported experience of radiofrequency ablation (RFA) of pancreatic tumors. The pancreas is surrounded by structures such as the stomach, duodenum, and colon and concerns regarding the risks of thermal injury to these structures have limited the use of RFA for nonresectable pancreatic tumors.

CASE REPORT

This brief report describes the application of this technique for the treatment of a metastasis from renal cell carcinoma localized at the body-tail portion of the pancreas in a 77-year-old man and the outcome of the procedure at 1-year follow-up.

CONCLUSIONS

In our experience, RFA is feasible also for metastatic lesion at the pancreas and it was safely carried out in this case. Long-term follow-up and larger series are necessary to assess the spectrum of complications and the true oncologic efficacy.

Current medical treatment of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (NETs) consist of a wide group of neoplasms, with different biological behaviors in terms of aggressiveness and hormone production. In the last two decades, significant progress has been observed in our understanding of their biology, diagnosis and treatment. Surgery remains to be the only curative approach, but unfortunately the diagnosis is often delayed due to the slow growth of these tumors and the difficulty in identifying the symptoms related to the tumor-released hormones. In addition to surgery, other approaches to control the disease are biological therapy consisting of somatostatin analogs and interferon (IFN), systemic chemotherapy, radioligand therapy and local therapy with chemoembolization. Several newer cytotoxic agents, including irinotecan, gemcitabine, taxanes, oxaliplatin, capecitabine and PS-341 have been studied in metastatic patients. Considering the high vascularity of these tumors, antiangiogenic agents like endostatin and thalidomide have also been evaluated in advanced NETs. Although these agents seem to have potential activity in NETs and may increase progression free survival, none of these currently available medical therapeutic options are curative. While more efficient novel strategies are to be developed, the rationale use of the current therapeutic options may improve quality of life, control the symptoms related to the hypersecretion of hormones and/or peptides, control tumor proliferation and prolong survival in patients suffering from NETs.