Percutaneous Radiofrequency Ablation of Unresectable Locally Advanced Pancreatic Cancer: Preliminary Results

Advances in Image-Guided Ablation Therapies for Solid Tumors

Image-guided solid tumor ablation methods have significantly advanced in their capability to target primary and metastatic tumors. These techniques involve noninvasive or percutaneous insertion of applicators to induce thermal, electrochemical, or mechanical stress on malignant tissue to cause tissue destruction and apoptosis of the tumor margins. Ablation offers substantially lower risks compared to traditional methods. Benefits include shorter recovery periods, reduced bleeding, and greater preservation of organ parenchyma compared to surgical intervention. Due to the reduced morbidity and mortality, image-guided tumor ablation offers new opportunities for treatment in cancer patients who are not candidates for resection. Currently, image-guided ablation techniques are utilized for treating primary and metastatic tumors in various organs with both curative and palliative intent, including the liver, pancreas, kidneys, thyroid, parathyroid, prostate, lung, breast, bone, and soft tissue. The invention of new equipment and techniques is expanding the criteria of eligible patients for therapy, as now larger and more high-risk tumors near critical structures can be ablated. This article provides an overview of the different imaging modalities, noninvasive, and percutaneous ablation techniques available and discusses their applications and associated complications across various organs.

Endoscopic Ultrasound-Guided Ablation of Premalignant Pancreatic Cysts and Pancreatic Cancer

Pancreatic cancer is on the rise and expected to become the second leading cause of cancer-related death by 2030. Up to a one-fifth of pancreatic cancers may arise from mucinous pancreatic cysts, which are frequently present in the general population. Currently, surgical resection is the only curative approach for pancreatic cancer and its cystic precursors. However, only a dismal proportion of patients are eligible for surgery. Therefore, novel treatment approaches to treat pancreatic cancer and precancerous pancreatic cysts are needed. Endoscopic ultrasound (EUS)-guided ablation is an emerging minimally invasive method to treat pancreatic cancer and premalignant pancreatic cysts. Different ablative modalities have been used including alcohol, chemotherapy agents, and radiofrequency ablation. Cumulative data over the past two decades have shown that endoscopic ablation of mucinous pancreatic cysts can lead to cyst resolution in a significant proportion of the treated cysts. Furthermore, novel data are emerging about the ability to endoscopically ablate early and locally advanced pancreatic cancer. In this review, we aim to summarize the available data on the efficacy and safety of the different EUS-ablation modalities for the management of premalignant pancreatic cysts and pancreatic cancer.

Locoregional Thermal and Chemical Tumor Ablation: Review of Clinical Applications and Potential Opportunities for Use in Low- and Middle-Income Countries

This review highlights opportunities to develop accessible ablative therapies to reduce the cancer burden in LMICs.

Interventional Radiology in the Treatment of Pancreatic Adenocarcinoma: Present and Future Perspectives

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease; patients' long-term survival is strictly linked to the surgical resection of the tumor but only a minority of patients (2-3%) have a resectable disease at diagnosis. In patients with surgically unresectable disease, interventional radiology is taking on an increasing role in treatment with the application of loco-regional percutaneous therapies. The primary purposes of this narrative review are to analyze the safety and efficacy of ablative techniques in the management of borderline resectable and locally advanced diseases and to underline the role of the interventional radiologist in the management of patients with distant metastases. The secondary purpose is to focus on the synergy between immunotherapy and ablative therapies.

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.

Efficacy and Safety of Endoscopic Ultrasound-Guided Radiofrequency Ablation for Pancreatic Neuroendocrine Tumors: A Systematic Review and Metanalysis

Introduction: The development of dedicated endoscopes and the technical evolution of endoscopic ultrasound (EUS) have allowed a direct approach to pancreatic neoplastic lesions both for diagnosis and treatment. Among the more promising targets are pancreatic neuroendocrine tumors (Pan-NETs). Aim: to describe the evolution of endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) with particular attention to the treatment of PanNETs, focusing on safety and clinical efficacy of the technique. Methods: MEDLINE, Scopus, and Cochrane Library databases were searched for studies reporting about EUS-RFA for the treatment of PanNETs. Studies with outcomes of interest were selected and results were reported to describe clinical success, complications, fol-low-ups, and electrodes used. Clinical success was defined as the disappearance of clinical symp-toms for functional (F-) PanNETs and as complete ablation per nonfunctional (NF)-PanNETs. The pooled data were analyzed by a random-effects model. Results: Nineteen studies were selected, including 183 patients (82 males, 44.8%) with 196 lesions (101 F-PanNETs and 95 NF-PanNETs). Pooled estimates for the overall AE rates for the clinical efficacy were 17.8% (95% CI 9.1-26.4%) and 95.1% (95% CI 91.2-98.9%) for F-PanNETs and 24.6% (95% CI 7.4-41.8%) and 93.4% (95% CI 88.4-98.4%) for NF-PanNETs. Conclusions: EUS-RFA appears to be a mini-invasive technique with a good safety and efficacy profile for the treatment of F- and NF-PanNETs. EUS-RFA could be of-fered as possible alternative to surgery for the treatment of low-grade NF- or F-PanNETs, especially for those patients that are not eligible or are at high-risk for surgery.

Nine-year survival of a 60-year-old woman with locally advanced pancreatic cancer under repeated open approach radiofrequency ablation: A case report

BACKGROUND

Radiofrequency ablation (RFA) is gaining popularity as an additional therapy for pancreatic ductal adenocarcinoma. RFA appears to be an attractive treatment option for patients with unresectable, locally advanced and nonmetastatic pancreatic cancer.

CASE SUMMARY

A 60-year-old woman with 2 mo intermittent upper abdominal pains was admitted to hospital. She had undergone radical gastrectomy (Billroth II) for gastric antral cancer. Contrast-enhanced computed tomography (CECT) and abdominal ultrasound displayed a primary tumor in the neck of the pancreas. Pathological examination showed that the lesion was a pancreatic ductal adenocarcinoma. According to the results of the imaging, open approach RFA was selected to treat the primary tumor. Eight months later, CECT follow-up revealed local recurrence of the tumor, and another open RFA was performed. Although there is evidence that RFA for recurrence of other cancers such as hepatocellular carcinoma may prolong patient survival, it remains unclear whether repeat RFA for local recurrence of pancreatic cancer is feasible. The patient continued to enjoy 9 years of life following the first RFA.

CONCLUSION

RFA of locally advanced, nonresectable, nonmetastatic, pancreatic tumor is characterized by feasibility-based treatment giving rise to tumor reduction based on improvement of quality of life.

Radiofrequency Hyperthermia Enhances Locally Delivered Oncolytic Immuno-Virotherapy for Pancreatic Adenocarcinoma

PURPOSE

To investigate the effect of radiofrequency hyperthermia (RFH)-enhanced oncolytic immuno-virotherapy on in vitro pancreatic adenocarcinoma cell line and in vivo rat pancreatic cancer model.

MATERIALS AND METHODS

Rat pancreatic adenocarcinoma cell line and 24 Lewis rats with orthotopic pancreatic adenocarcinomas underwent treatment with either (1) oncolytic virotherapy (talimogene laherparepvec [T-VEC]) plus RFH at 42 °C for 30 min; (2) oncolytic virotherapy-only; (3) RFH-only; or (4) saline (control). MTS assays and flow cytometry were used to analyze tumor cell viability and apoptosis levels 24 h after treatment. In the in vivo studies, bioluminescence optical/x-ray imaging and ultrasound imaging was used to assess tumor viability and size 7 and 14 days after treatment. Histopathologic analysis was performed after hematoxylin and eosin staining, TUNEL, Ki-67, and immunohistochemical staining with CD8 and ANK61.

RESULTS

Combination therapy (T-VEC + RFH) induced decreased cell viability and increased cell apoptosis compared to T-VEC alone, RFH alone, or control. Optical/x-ray imaging and ultrasound imaging demonstrated decreased tumor bioluminescent signal and tumor volume relative to baseline after combination therapy compared to T-VEC alone, RFH alone, or control. Histopathology demonstrated decreased tumor volume and cell proliferation, increased CD8⁺ T cell and NK cell infiltration in tumors treated with the combination therapy compared to other three groups.

CONCLUSION

RFH enhances locally delivered oncolytic immuno-virotherapy for pancreatic adenocarcinoma, with decreased cell viability and increased apoptosis observed after combination therapy in vitro, and decreased cell viability and tumor volume and increased immune cell infiltrate observed after combination therapy in vivo.

Minimally invasive image-guided therapy of primary and metastatic pancreatic cancer

Pancreatic cancer is a challenging malignancy with limited treatment options and poor life expectancy. The only curative option is surgical resection, but only 15%-20% of patients are resectable at presentation because more than 50% of patients has distant metastasis at diagnosis and the rest of them has locally advanced pancreatic cancer (LAPC). The standard of care first line treatment for LAPC patients is chemotherapy with or without radiation therapy. Recent developments in minimally invasive ablative techniques may add to the treatment armamentarium of LAPC. There are increasing number of studies evaluating these novel ablative techniques, including radiofrequency ablation, microwave ablation, cryoablation and irreversible electroporation. Most studies which included pancreatic tumor ablation, demonstrated improved overall survival in LAPC patients. However, the exact protocols are yet to set up to which stage of the treatment algorithm ablative techniques can be added and in what kind of treatment combinations. Patients with metastatic pancreatic cancer has dismal prognosis with 5-year survival is only 3%. The most common metastatic site is the liver as 90% of pancreatic cancer patients develop liver metastasis. Chemotherapy is the primary treatment option for patients with metastatic pancreatic cancer. However, when the tumor is not responding to chemotherapy or severe drug toxicity develops, locoregional liver-directed therapies can provide an opportunity to control intrahepatic disease progression and improve survival in selected patients. During the last decade new therapeutic options arose with the advancement of minimally invasive technologies to treat pancreatic cancer patients. These new therapies have been a topic of increasing interest due to the severe prognostic implications of locally advanced and metastatic pancreatic cancer and the low comorbid risk of these procedures. This review summarizes new ablative options for patients with LAPC and percutaneous liver-directed therapies for patients with liver-dominant metastatic disease.

Local ablation of pancreatic tumors: State of the art and future perspectives

BACKGROUND

Currently, the technologies most commonly used to treat locally advanced pancreatic cancer are radiofrequency ablation (RFA), microwave ablation, and irreversible (IRE) or reversible electroporation combined with low doses of chemotherapeutic drugs.

AIM

To report an overview and updates on ablative techniques in pancreatic cancer.

METHODS

Several electronic databases were searched. The search covered the years from January 2000 to January 2021. Moreover, the reference lists of the found papers were analysed for papers not indexed in the electronic databases. All titles and abstracts were analysed.

RESULTS

We found 30 studies (14 studies for RFA, 3 for microwave therapy, 10 for IRE, and 3 for electrochemotherapy), comprising 1047 patients, which were analysed further. Two randomized trials were found for IRE. Percutaneous and laparotomy approaches were performed. In the assessed patients, the median maximal diameter of the lesions was in the range of 2.8 to 4.5 cm. All series included patients unfit for surgical treatment, but Martin et al assessed a subgroup of patients with borderline resectable tumours who underwent resection with margin attenuation with IRE. Most studies administered chemotherapy prior to ablative therapies. However, several studies suggest that the key determinant of improved survival is attributable to ablative treatment alone. Nevertheless, the authors suggested chemotherapy before local therapies for several reasons. This strategy may not only downstage a subgroup of patients to curative-intent surgery but also support to recognize patients with biologically unfavourable tumours who would likely not benefit from ablation treatments. Ablation therapies seem safe based on the 1047 patients assessed in this review. The mortality rate ranged from 1.8% to 2%. However, despite the low mortality, the reported rates of severe post procedural complications ranged from 0%-42%. Most reported complications have been self-limiting and manageable. Median overall survival varied between 6.0 and 33 mo. Regarding the technical success rate, assessed papers reported an estimated rate in the range of 85% to 100%. However, the authors reported early recurrence after treatment. A distinct consideration should be made on whether local treatments induce an immune response in the ablated area. Preclinical and clinical studies have shown that RFA is a promising mechanism for inducing antigen-presenting cell infiltration and enhancing the systemic antitumour T-cell immune response and tumour regression.

CONCLUSION

In the management of patients with pancreatic cancer, the possibility of a multimodal approach should be considered, and conceptually, the combination of RFA with immunotherapy represents a novel angle of attack against this tumour.

Role of radio-ablative technique for optimizing the survival of patients with locally advanced pancreatic adenocarcinoma (Review)

Pancreatic ductal adenocarcinoma (PDAC) is one of the most common and frequently diagnosed malignant tumor of the pancreas with few treatment options and poor life expectancy. Despite the advances in the surgical field, 40% of the patients are diagnosed with locally advanced disease which is not suitable for surgery. Radio-frequency ablation (RFA) has been described as a new ‘weapon’ in the multimodal treatment of PDAC, representing a cytoreductive procedure which must be completed with radiotherapy or chemo-radiotherapy. A systematic research was carried out utilizing the PubMed database in regards to this subject, to evaluate the role of RFA in PDAC management. Abstracts, letters-to-the-editor and non-English language manuscripts were excluded. The literature showed that RFA can be used in open and laparoscopic surgery but it is also feasible for endoscopic ultrasound (EUS-guided RFA) or percutaneous approach. Even though we found optimistic and encouraging reports on overall survival (OS), randomized studies are still required to corroborate these findings. Our review research underline that surgical resection remains the only radical treatment option, RFA being a safe and feasible technique reserved for unresectable, non-metastatic pancreatic tumors. Its combination with oncological treatment can improve the OS of these patients.

Locally Advanced Pancreatic Cancer: Percutaneous Management Using Ablation, Brachytherapy, Intra-arterial Chemotherapy, and Intra-tumoral Immunotherapy

PURPOSE OF REVIEW

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive neoplasms, bearing a terrible prognosis. Stage III tumors, also known as locally advanced pancreatic cancer (LAPC), are unresectable, and current palliative chemotherapy regimens have only modestly improved survival in these patients. At this stage of disease, interventional techniques may be of value and further prolong life. The aim of this review was to explore current literature on locoregional percutaneous management for LAPC.

RECENT FINDINGS

Locoregional percutaneous interventional techniques such as ablation, brachytherapy, and intra-arterial chemotherapy possess cytoreductive abilities and have the potential to increase survival. In addition, recent research demonstrates the immunomodulatory capacities of these treatments. This immune response may be leveraged by combining the interventional techniques with intra-tumoral immunotherapy, possibly creating a durable anti-tumor effect. This multimodality treatment approach is currently being examined in several ongoing clinical trials. The use of certain interventional techniques appears to improve survival in LAPC patients and may work synergistically when combined with immunotherapy. However, definitive conclusions can only be made when large prospective (randomized controlled) trials confirm these results.

Role of Radiofrequency Ablation in the Management of Unresectable Pancreatic Cancer

Pancreatic cancer is one of the most aggressive malignancies of the digestive tract and carries a poor prognosis. The majority of patients have advanced disease at the time of diagnosis. Surgical resection offers the only curative treatment, but only a small proportion of patients can undergo surgical resection. Radiofrequency ablation (RFA) is a well-known modality in the management of solid organ tumors, however, its utility in the management of pancreatic cancer is under investigation. Since the past decade, there is increasing use of RFA as it provides a feasible palliation treatment in the management of unresectable pancreatic cancer. RFA causes tumor cytoreduction through multiple mechanisms such as coagulative necrosis, protein denaturation, and activation of anticancer immunity. The safety profile of RFA is controversial because of the high risk for complications, however, small prospective and retrospective studies have shown promising results in its applicability for palliative management of unresectable pancreatic malignancies. In this review, we discuss different approaches of RFA, their indications, technical accessibility, safety, and major complications in the management of unresectable pancreatic cancer.

The role of interventional radiology in the treatment of patients with pancreatic cancer

Interventional radiology (IR) provides minimally invasive therapeutic and palliative options for the treatment of pancreatic cancer depending on the stage of the disease. IR plays a critical, and also a very effective role, in both pre- and post-operative care of the patients with early stage resectable disease and also in palliative treatment of the patients with locally advanced or metastatic disease. In this article, we aimed to present the capability and the limitations of IR procedures including: local treatment options of primary and metastatic pancreatic cancer, palliation of biliary and intestinal obstructions, minimally invasive treatment of post-operative complications, and pain management.

Imaging response evaluation after local ablative treatments in locally advanced pancreatic cancer: an expedited systematic review

BACKGROUND

Several local ablative modalities have been introduced for the treatment of locally advanced pancreatic cancer (LAPC). However, there is no consensus on how to evaluate the imaging response after treatment. A systematic review was performed regarding the use of imaging for response assessment in LAPC.

METHODS

A systematic literature search was conducted in PubMed. Studies reporting imaging outcomes were included in the review. Studies were excluded if the imaging outcomes could not be differentiated between different disease stages, tumor histology or surgical approaches.

RESULTS

Thirty-four studies were included in the analysis. Fourteen studies used standardized response criteria, while six studies did not report the response evaluation method. The rest used self-determined criteria, absolute size comparisons or similar methods. One study found a correlation between early systemic progression (<6 months) and overall survival.

CONCLUSION

There was notable variation in the use of imaging for response assessment in LAPC. This significantly hinders cross-comparison of results among studies. There is currently only sparse evidence of an association between imaging responses and overall survival. The field calls for standardized recommendations regarding the choice of response assessment method, timing of scans, target definition and reporting of outcomes.

Effects of high-intensity focused ultrasound treatment on peripancreatic arterial and venous blood vessels in pancreatic cancer

The present study aimed to evaluate the safety of high-intensity focused ultrasound (HIFU) treatment on peripancreatic arterial and venous blood vessels in patients with pancreatic cancer. This trial included 15 patients with pancreatic cancer (9 females and 6 males; age, 39-81 years; median age, 62 years). All patients underwent preoperative computed tomography (CT) or magnetic resonance imaging (MRI) and color Doppler flow imaging (CDFI) to assess the vascular hemodynamics of peripancreatic arterial and venous blood vessels pre-treatment. These patients were re-examined within 1 week post-HIFU treatment. Then, vascular adverse events were observed and followed up clinically. Prior to HIFU treatment, vessel involvement was recorded in 13 patients, including tumor lesions invading 19 veins and 14 arteries, which refers to the growth of pancreatic tumor lesions surrounding blood vessels, or tumor growth into blood vessels. In addition, 9 veins and 13 arteries were <1 cm from the lesions. The hemodynamic parameters of peripancreatic vessels were measured using CDFI, including mean blood flow velocity, peak systolic blood flow velocity, vascular resistance index, vascular pulsatility index, vascular diameter, vascular blood flow and other indicators, to assess vascular perfusion in CT/MRI. There were no significant differences in preoperative and postoperative hemodynamic data (P>0.05). Overall, HIFU demonstrated no negative effects on peripancreatic arterial and venous blood vessels in patients with pancreatic cancer, even with tumor lesions wrapped in blood vessels. In addition, no complications of vascular stenosis and vascular adverse events were observed in the present study.

Possible involvement of HSP70 in pancreatic cancer cell proliferation after heat exposure and impact on RFA postoperative patient prognosis

Purpose

As an alleviative treatment measured in patients with unresectable advanced pancreatic cancer, radiofrequency ablation (RFA) needed more clinical data to prove its advantages and to explore limitations in its utilization. This study was determined to observe the efficacy of RFA, and to explore its impact on perioperative periphery carcinoma as well as the normal pancreatic tissues.

Methods

Clinical data of 32 patients with pancreatic cancer accepted RFA surgery were collected. Followed up patients' pain degree and the changes in serum tumor markers CA19-9 and CA 242 before and after surgery. Ex vivo, gave human pancreatic cancer cell line PANC-1 heat treatment to simulate the heat exposure condition periphery carcinoma was experienced during RFA surgery, and to observe the proliferation rate and HSP70 expression change compared with control group.

Results

Of the 32 patients, 1 died of upper gastrointestinal hemorrhage, and 29 survived for more than 5 months, 2 of which for more than 16 months. The average CA19-9 and CA 242 levels of the patients were significantly decreased in 3 months after surgery (t = 9.873, 5.978, P < 0.001). During in vitro experiments, the proliferation rate of PANC-1 cells after heating was significantly increased, accompanied with the increased HSP70 expression. The addition of HSP70 inhibitor can inhibit the rise of proliferation after heat therapy.

Conclusion

Utilizing RFA treat patients with unresectable advanced pancreatic cancer, could effectively relieve the pain, decline jaundice, and deduce tumor marker levels significantly. However, it failed to extend the long-term survival rate of the patients significantly. This study found that a higher proliferative rate accompanied with a higher HSP70 expression level were observed on in vitro cultured pancreatic carcinoma cells after heat treatment, which could be altered by HSP70 inhibitor. And these findings indicated that the heat exposure might impact periphery carcinoma during RFA surgery and HSP70 might play an important role in patients' prognosis.

Anesthesia for Percutaneous Radiofrequency Tumor Ablation (PRFA): A Review of Current Practice and Techniques

Percutaneous radiofrequency ablation (PRFA) of solid tumors is a minimally invasive procedure used to treat primary or metastatic cancer lesions via needle targeted thermal energy transfer. Some of the most common tumor lesions treated using PRFA include those within the liver, lungs and kidneys. Additionally, bone, thyroid, and breast lesions can also be treated. In most cases, this procedure is performed outside of the operating room in a specialized radiology suite. As a result, the clinician must adapt in many cases to the specific environmental issues attendant to providing anesthesia outside the operating room, including the lack of availability of an anesthesia machine in some cases, and frequently a lack of adequate scavenging and other specialized monitoring and equipment. At this time, routine practice and anesthetic prescriptions for PRFA can vary widely, ranging from patients receiving local anesthesia alone, to monitored anesthesia care, to regional anesthesia, to combined regional and general anesthesia. The choice of anesthetic technique will depend on tumor location and practitioner experience. This review aims to summarize the current state of the art in terms of anesthetic techniques for patients undergoing PRFA of solid tumors.

Locally Advanced Pancreatic Cancer: Work-Up, Staging, and Local Intervention Strategies

Locally advanced pancreatic cancer (LAPC) has several definitions but essentially is a nonmetastasized pancreatic cancer, in which upfront resection is considered not beneficial due to extensive vascular involvement and consequent high chance of a nonradical resection. The introduction of FOLFIRINOX chemotherapy and gemcitabine-nab-paclitaxel (gem-nab) has had major implications for the management and outcome of patients with LAPC. After 4-6 months induction chemotherapy, the majority of patients have stable disease or even tumor-regression. Of these, 12 to 35% are successfully downstaged to resectable disease. Several studies have reported a 30-35 months overall survival after resection; although it currently remains unclear if this is a result of the resection or the good response to chemotherapy. Following chemotherapy, selection of patients for resection is difficult, as contrast-enhanced computed-tomography (CT) scan is unreliable in differentiating between viable tumor and fibrosis. In case a resection is not considered possible but stable disease is observed, local ablative techniques are being studied, such as irreversible electroporation, radiofrequency ablation, and stereotactic body radiation therapy. Pragmatic, multicenter, randomized studies will ultimately have to confirm the exact role of both surgical exploration and ablation in these patients. Since evidence-based guidelines for the management of LAPC are lacking, this review proposes a standardized approach for the treatment of LAPC based on the best available evidence.

Safety of radiofrequency ablation in patients with locally advanced, unresectable pancreatic cancer: A phase II study

INTRODUCTION

Radiofrequency ablation (RFA) has been proposed as a new treatment option for locally advanced, unresectable pancreatic cancer (LAPC). In preparation of a randomized controlled trial (RCT), the aim of this phase II study was to assess the safety of RFA for patients with LAPC.

MATERIALS AND METHODS

Patients diagnosed with LAPC confirmed during surgical exploration between November 2012 and April 2014 were eligible for inclusion. RFA probes were placed under ultrasound guidance with a safety margin of at least 10 mm from the duodenum and 15 mm from the portomesenteric vessels. During RFA, the duodenum was continuously perfused with cold saline to reduce risk for thermal damage. Primary outcome was defined as the amount of major complications (Clavien-Dindo grade ≥III). RFA-related complications were predefined as: pancreatic fistula, pancreatitis, thermal damage to the portomesenteric vessels and duodenal perforation.

RESULTS

In total, 17 patients underwent RFA. Delayed gastric emptying (DGE) requiring endoscopic feeding tube placement occurred in 4 patients (24%) as only major complication. Five patients (29%) had a major complication other than DGE. One (6%) RFA-related major complications occurred. One patient (6%) died due to complications from a biliary leak following hepaticojejunostomy. After evaluation of the first 5 patients, gastrojejunostomy was no longer performed routinely. Since then severe DGE seemed to occur less (3/5 vs. 3/12 grade C DGE).

CONCLUSION

RFA is a major, but safe procedure for patients with LAPC if performed with strict predefined safety criteria. A RCT is currently investigating the true effectiveness of RFA in patients with LAPC.

Ablation treatments in unresectable pancreatic cancer

Ablation treatments have been increasingly applied as an alternative treatment for unresectable locally advanced pancreatic cancer (LAPC). The goal of LAPC therapy is surgical resection with negative margins (R0); however, that can be achieved only in a minority of patients and only following neoadjuvant treatment. Ablation might be useful for those patients with unresectable LAPC that do not progress towards metastatic stage and do not experience a true downstaging. Indeed, some LAPC that tend to grow locally, might be the subgroup of tumors that could benefit from ablation. Experience is necessary to select patients and the technique to adopt, since serious or fatal complications can occur. This review aims to discuss the role of ablation treatments in LAPC, with a unique focus on radiofrequency ablation and irreversible electroporation.

Pancreatic cancer – What's next?

This chapter focuses on the most recent advantages in the medical treatment of localized pancreatic cancer.

Efficacy and safety of CT-guided high-dose-rate interstitial brachytherapy in primary and secondary malignancies of the pancreas

PURPOSE

To evaluate efficacy and safety of CT-guided iBT in patients with primary and secondary malignancies of the pancreas.

MATERIAL AND METHODS

13 patients with 13 lesions of the pancreatic corpus and tail were included: 8 secondary malignancies (metastatic lesions = ML) and 5 primary malignancies, including 3 primary tumors (PT) and 2 isolated locoregional recurrences (ILR) after surgical resection were treated with image-guided iBT using a 192iridium source (single fraction irradiation). Every 3 months after treatment clinical and imaging follow-up were conducted to evaluate efficacy. Peri- and postinterventional complications were assessed descriptively.

RESULTS

The median diameter of the gross tumor volume (GTV) was 3 cm (range 1-6.5 cm), treated with a median D100 (minimal enclosing tumor dose) of 15.3 Gy (range 9.2-25.4 Gy). Local tumor control (LTC) was 92.3% within a median follow-up period of 6.7 months (range 3.2-55.7 months). Cumulative median progression free survival (PFS) was 6.2 months (range 2.8-25.7 months; PFS of primary and secondary malignancies was 5.8 and 6.2 months, respectively). Cumulative median over all survival (OS) after iBT was 16.2 months (range 3.3-55.7 months; OS of primary and secondary malignancies was 7.4 months and 45.6 months, respectively). 1 patient developed mild acute pancreatits post iBT, spontanously resolved within 1 week. No severe adverse events (grade 3+) were recorded.

CONCLUSION

Image-guided iBT is a safe and particularly effective treatment in patients with primary and secondary malignancies of the pancreas and might provide a well-tolerated additional therapeutic option in the multidisciplinary management of selected patients.

Ultrasound-guided percutaneous procedures in pancreatic diseases: new techniques and applications

Ultrasound (US) is not only an important diagnostic tool for the evaluation of the pancreas, but is also a fundamental imaging technique to guide percutaneous interventions for several pancreatic diseases (fluid aspiration and drainage; invasive diagnosis by means fine-needle aspiration and core-needle biopsy; tumour ablation by radiofrequency, microwaves, irreversible electroporation, cryoablation, and high-intensity focused US). Technical improvements, such as contrast media and fusion imaging, have recently increased precision and safety and reduced procedure-related complications. New treatment US techniques for the ablation of pancreatic tumours, such as contrast-enhanced US and multimodality fusion imaging, have been recently developed and have elicited a growing interest worldwide. The purpose of this article was to review the most up-to-date role of US in percutaneous procedures for pancreatic diseases.

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

PURPOSE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Palliative therapy in pancreatic cancer-interventional treatment with radiofrequency ablation/irreversible electroporation

Pancreatic cancer (PC) is a solid tumor with still a dismal prognosis. Diagnosis is usually late, when the disease is metastatic or locally advanced (LAPC). Only 20% of PC are amenable to surgery at the time of diagnosis and the vast majority of them, despite radically resected will unavoidably recur. The treatment of LAPC is a challenge. Current guidelines suggest to adopt systemic therapies upfront, based on multi-drugs chemotherapy regimens. However, the vast majority of patients will never experience conversion to surgical exploration and radical resection. Thus, there a large subgroup of LAPC patients where the only therapeutic chance is to offer palliative treatments, such as interventional ablative treatments, in order to obtain a cytoreduction of the tumor, trying to delay its growth and spread. Radiofrequency ablation (RFA) and irreversible electroporation (IRE) demonstrated to be safe and effective in obtaining a local control of the disease with some promising oncological results in terms of overall survival (OS). However, they should be adopted as a treatment strategy to adopt in parallel with other systemic therapies, within multidisciplinary choices. They are not free from complications, even serious, thus they should applied only in specialized centers of pancreatology. This review depicts the state of the art of the two techniques.

Irreversible Electroporation in Patients with Pancreatic Cancer: How Important Is the New Weapon?

Background

Pancreatic cancer (PC) is a deadly disease with poor prognosis in the general population. We aimed to quantitate overall survival of patients with PC after irreversible electroporation (IRE) and the incidence of relevant complications.

Methods

We performed a literature search via five electronic databases (PubMed, Embase, Web of Science, Scopus, and Cochrane Library databases) up to August 2017. The primary outcomes were overall survival and prognosis. Secondary outcomes included the response of post-IRE complications. Fixed-effects or random-effects meta-analysis was conducted to pool these data.

Results

A total of 15 eligible articles involving 535 patients were included. The primary outcomes showed that the pooled prevalence estimates of overall survival were 94.1% (95% CI: 90.7–97.5), 80.9% (95% CI: 72.5–89.4), 54.5% (95% CI: 38.3–70.6), and 33.8% (95% CI: 14.2–53.5) at 3, 6, 12, and 24 months, and the pooled prevalence data of complete response (CR) at 2 months, partial response (PR) at 3 months, and progression at 3 months were 12.5% (95% CI: 2.9–22.2), 48.5% (95% CI: 39.4–57.6), and 19.7% (95% CI: 7.3–32.2), respectively. The secondary outcomes showed that the pooled prevalence values of post-IRE complications were abscess 6.6% (95% CI: 0.2–13), fistula 10.6% (95% CI: 2.5–18.7), pain 33.5% (95% CI: 14.5–52.5), infection 16.1% (95% CI: 3.9–28.4), thrombosis 4.9% (95% CI: 1.2–8.5), pancreatitis 7.2% (95% CI: 3.1–11.2), bleeding 4.2% (95% CI: −0.5–8.9), cholangitis 4.2% (95% CI: −0.5–8.9), nausea 9.6% (95% CI: 4.4–14.8), biliary obstruction 13.8% (95% CI: 4.2–23.3), chest tightness 7.6% (95% CI: 0.5–14.6), and hypoglycemia 5.9% (95% CI: −0.4–12.2).

Conclusions

This meta-analysis indicated a clear survival benefit for PC patients who received irreversible electroporation therapy, although future safety and effectivity monitoring from more large-scale studies will be needed.

Radiofrequency ablation for locally advanced pancreatic cancer: SMAD4 analysis segregates a responsive subgroup of patients

PURPOSE

SMAD4 mutational status correlates with pancreatic ductal adenocarcinoma (PDAC) failure pattern. We investigated in a subset of locally advanced patients submitted to radiofrequency ablation (RFA) whether the assessment of SMAD4 status is a useful way to select the patients.

METHODS

Clinical, radiological, and follow-up details of patients submitted to RFA for locally advanced pancreatic cancer (LAPC), in whom cytohistological material was available at our institution, were retrospectively retrieved. SMAD4 expression was evaluated by immunohistochemistry (IHC) and considered "negative" or "positive." The survival analysis was conducted using Kaplan-Meier and Cox proportional hazards models.

RESULTS

The study population consisted of 30 patients. Thirteen patients (43.3%) received RFA upfront, whereas 17 (56.7%) after induction treatments. SMAD4 was mutant in 18 out of 30 patients (60%). The overall estimated post-RFA disease-specific survival (DSS) was 15 months (95% CI 11.64-18.35). The estimated post-RFA DSS of patients with wild-type and mutant SMAD4 was 22 and 12 months, respectively (log-rank p < 0.05). At the multivariate analysis, SMAD4 was the only independent predictor of survival (p = 0.05). The pattern of failure was not associated with SMAD4 status (p = 0.4).

CONCLUSIONS

Within patients undergoing RFA for LAPC, SMAD4 analysis could segregate a subgroup of subjects with improved survival, who likely benefited from tumor ablation.

Locally Advanced Pancreatic Cancer: A Review of Local Ablative Therapies

Pancreatic cancer is typically characterized by its aggressive tumor growth and dismal prognosis. Approximately 30% of patients with pancreatic cancer present with locally advanced disease, broadly defined as having a tumor-to-artery interface >180°, having an unreconstructable portal vein or superior mesenteric vein and no signs of metastatic disease. These patients are currently designated to palliative systemic chemotherapy, though median overall survival remains poor (approximately 11 months). Therefore, several innovative local therapies have been investigated as new treatment options for locally advanced pancreatic cancer (LAPC). This article provides an overview of available data with regard to morbidity and oncological outcome of novel local therapies for LAPC.

Percutaneous ablation of pancreatic cancer

Pancreatic ductal adenocarcinoma is a highly aggressive tumor with an overall 5-year survival rate of less than 5%. Prognosis and treatment depend on whether the tumor is resectable or not, which mostly depends on how quickly the diagnosis is made. Chemotherapy and radiotherapy can be both used in cases of non-resectable pancreatic cancer. In cases of pancreatic neoplasm that is locally advanced, non-resectable, but non-metastatic, it is possible to apply percutaneous treatments that are able to induce tumor cytoreduction. The aim of this article will be to describe the multiple currently available treatment techniques (radiofrequency ablation, microwave ablation, cryoablation, and irreversible electroporation), their results, and their possible complications, with the aid of a literature review.