Radiofrequency ablation of locally advanced pancreatic adenocarcinoma: An overview

Irreversible electroporation to bring initially unresectable locally advanced pancreatic adenocarcinoma to surgery: the IRECAP phase II study

OBJECTIVES

The aim of the IRECAP study was to evaluate the rate of locally advanced pancreas cancer patients (LAPC) who could undergo R0 or R1 surgery after irreversible electroporation (IRE).

MATERIALS AND METHODS

IRECAP study is a phase II, single-center, open-label, prospective, non-randomized trial registered at clinicaltrials.gov (NCT03105921). Patients with LAPC were first treated by 3-month neo-adjuvant chemotherapy in order to avoid inclusion of either patients with LAPC having become resectable after chemotherapy or patients with rapid disease progression. In cases of stable disease, IRE was performed percutaneously under CT guidance. Surgery was planned between 28 and 90 days after IRE. Tumor specimens were studied to evaluate the resection margins (R0/R1/R2).

RESULTS

Six men and 11 women were included (median age 61 years, range 37-77 years). No IRE-related death was observed. Ten patients (58%, 10/17) experienced 25 serious adverse events related to IRE. Four patients progressed between IRE and surgery and were excluded from surgery. Thirteen patients were finally operated, six withheld for pancreas resection, three for diffuse peritoneal carcinosis, two for massive vascular entrapment, and one for hepato-cellular carcinoma not diagnosed before surgery. Rate of R1-R0 was 35% (n = 6/17). Median overall survival was 31 months (95% CI; 4-undefined) for the six patients with R0/R1 resection and 21 months (95% CI; 4-25) for the 11 patients without resection or R2 resection (logrank p = 0.044).

CONCLUSION

After neoadjuvant chemotherapy, IRE could provide R0 or R1 resection in 35% of LAPC, which seems to be associated with higher OS.

CLINICAL RELEVANCE STATEMENT

After induction chemotherapy, stable locally advanced pancreatic cancers can be treated by irreversible electroporation, which could lead to a secondary 35% rate of R0 or R1 surgical resection which may be associated with a significantly higher overall survival.

KEY POINTS

• In cases of unresectable LAPC (locally advanced pancreatic cancer), percutaneous irreversible electroporation (pIRE) is feasible (100% success rate of the procedure), but is associated with a 58% rate of grade 3-4 adverse events. • In patients with unresectable LAPC, pIRE could lead 35% of patients to R0-R1 surgical resection. • From IRE, median overall survival was 31 months (95% CI; 4-undefined) for the patients with R0/R1 resection and 21 months (95% CI; 4-25) for the patients without resection or R2 resection (logrank p = 0.044).

Pancreatic Cancer: Challenges and Opportunities in Locoregional Therapies

Simple Summary

Pancreatic cancer is a serious ongoing global health burden, with an overall 5-year survival rate of less than 5%. One major hurdle in the treatment of this disease is the predominantly elderly patient population, leading to their ineligibility for curative surgery and a low rate of successful outcomes. Systemic administration introduces chemo-agents throughout the body via the blood, attacking not only tumours but also healthy organs. When localised interventions are employed, chemo-agents are retained specifically at tumour site, minimizing unwanted toxicity. As a result, there is a growing interest in finding novel localised interventions as alternatives to systemic therapy. Here, we present a detailed review of current locoregional therapies used in pancreatic cancer therapy. This work aims to present a thorough guide for researchers and clinicians intended to employ established and novel localised interventions in the treatment of pancreatic cancer. Furthermore, we present our insights and opinions on the potential ideals to improve these tools.

Abstract

Pancreatic cancer (PC) remains the seventh leading cause of cancer-related deaths worldwide and the third in the United States, making it one of the most lethal solid malignancies. Unfortunately, the symptoms of this disease are not very apparent despite an increasing incidence rate. Therefore, at the time of diagnosis, 45% of patients have already developed metastatic tumours. Due to the aggressive nature of the pancreatic tumours, local interventions are required in addition to first-line treatments. Locoregional interventions affect a specific area of the pancreas to minimize local tumour recurrence and reduce the side effects on surrounding healthy tissues. However, compared to the number of new studies on systemic therapy, very little research has been conducted on localised interventions for PC. To address this unbalanced focus and to shed light on the tremendous potentials of locoregional therapies, this work will provide a detailed discussion of various localised treatment strategies. Most importantly, to the best of our knowledge, the aspect of localised drug delivery systems used in PC was unprecedentedly discussed in this work. This review is meant for researchers and clinicians considering utilizing local therapy for the effective treatment of PC, providing a thorough guide on recent advancements in research and clinical trials toward locoregional interventions, together with the authors’ insight into their potential improvements.

US-Guided Percutaneous Radiofrequency Ablation of Locally Advanced Pancreatic Adenocarcinoma: A 5-Year High-Volume Center Experience

PURPOSE

 The aim of this study was to investigate the safety and effectiveness of percutaneous radiofrequency ablation (RFA) in locally advanced pancreatic cancer (LAPC) of the pancreatic body by assessing the overall survival of patients and evaluating the effects of the procedure in the clinical and radiological follow-up.

MATERIALS AND METHODS

 Patients with unresectable LAPC after failed chemoradiotherapy for at least six months were retrospectively included. Percutaneous RFA was performed after a preliminary ultrasound (US) feasibility evaluation. Contrast-enhanced computed tomography (CT) and CA 19.9 sampling were performed before and 24 hours and 30 days after the procedure to evaluate the effects of the ablation. Patients were followed-up after discharge considering the two main endpoints: procedure-related complications and death.

RESULTS

 35 patients were included, 5 were excluded. All patients underwent RFA with no procedure-related complications reported. The mean size of tumors was 49 mm before treatment. The mean dimension of the ablated necrotic zone was 32 mm, with a mean extension of 65 % compared to the whole tumor size. Tumor density was statistically reduced one day after the procedure (p < 0.001). The mean CA 19.9 levels before and 24 hours and 30 days after the procedure were 285.8 U/mL, 635.2 U/mL, and 336.0 U/mL, respectively, with a decrease or stability at the 30-day evaluation in 80 % of cases. The mean survival was 310 (65-718) days.

CONCLUSION

 Percutaneous RFA of LAPC is a feasible technique in patients who cannot undergo surgery, with great debulking effects and a very low complication rate.

The underlying molecular mechanism of intratumoral radiofrequency hyperthermia-enhanced chemotherapy of pancreatic cancer

Background

To investigate the underlying molecular mechanisms of radiofrequency hyperthermia (RFH)-enhanced direct chemotherapy of pancreatic cancers.

Method

Rat ductal PaCa cell line DSL-6A/C1 and orthotopic pancreatic cancers of Lewis rats were divided into four study groups with various treatments: i) phosphate-buffered saline (PBS) as a control; ii) RFH alone; iii) intratumoral chemotherapy alone (gemcitabine); and (iv) combination therapy of gemcitabine plus intratumoral RFH at 42 ​°C for 30 ​min. In the in-vitro confirmation experiments, the viability and apoptosis of DSL-6A/C1 cells in each treatment group were evaluated using cell live/dead staining, flow cytometry, and Western blot. In the in vivo validation experiments, related proteins were evaluated by immunohistochemistry (IHC) staining of tumors.

Results

Of the in-vitro experiments, the lowest cell viability and more apoptotic cells were shown in the group with combination therapy compared to other treatments. Western blot data showed elevated Bax/Bcl-2, Caspase-3, and HSP70 expressions in DSL cells with combination therapy, compared to other treatments. Of the in vivo experiments, IHC staining detected the significantly increased expressions of HSP70, IL-1β, TNF-ɑ, Bax, and Caspase-3 in pancreatic cancer tissues of the animal group treated by combination therapy of gemcitabine with RFH.

Conclusion

Molecular imaging-guided interventional RFH can significantly enhance the chemotherapeutic effect on pancreatic cancers via potential molecular mechanisms of up-regulating Bax/caspase-3-dependent apoptosis pathways.

Open radiofrequency ablation as upfront treatment for locally advanced pancreatic cancer: Requiem from a randomized controlled trial

BACKGROUND

Local ablation of pancreatic cancer has been suggested as an option to manage locally advanced pancreatic cancer (LAPC) although no robust evidence has been published to date to support its application. The aim of this study is to compare overall survival (OS) and progression-free survival (PFS) in patients receiving both radiofrequency ablation (RFA) and conventional chemoradiotherapy (CHRT) with patients receiving CHRT only.

METHODS

This is a multicentre prospective randomized controlled trial (RCT). Patients with LAPC diagnosed by the Pancreas-Ablation-Team-Verona were randomly assigned to open RFA (Group A) or CHRT (Group B). Survival analyses were performed using the Kaplan-Meier method and compared using the log-rank test. Statistical significance was set at p < 0.05.

RESULTS

One hundred LAPC patients were enrolled from January 2014 to August 2016. 33% of patients in Group A did not receive the designated procedure because of intraoperative findings of liver (18.7%) or peritoneal metastases (43.8%), or technical contraindications (37.5%). We did not observe any statistically significant survival benefit from RFA compared to CHRT, neither in terms of OS (medians of 14.2 months and 18.1 months, respectively, p = 0.639) nor PFS (medians of 8 months and 6 months respectively, p = 0.570). Mortality was nil and RFA-related morbidity was 15.6%. In 13% of subjects, conversion to surgery occurred (2 after RFA and 11 after CHRT).

CONCLUSIONS

This is the first RCT evaluating the impact of upfront RFA in the multimodal treatment of LAPC. Compared to CHRT, RFA alone did not provide any advantage in terms of OS or PFS. It could be considered as a therapeutic option for LAPC within a multimodal context and after neoadjuvant therapies.

Elastography of pancreatic ductal adenocarcinoma following EUS-guided radiofrequency ablation (with video)

Patients presenting with pancreatic ductal adenocarcinoma in an advanced inoperable stage receive chemoradiotherapy. Endoscopic ultrasound guided radiofrequency ablation (EUS-RFA) has been proposed as a new therapeutic option for these patients alongside chemotherapy. The evaluation of treatment response is mainly based on radiological evaluation of the changes in tumour size. Unfortunately, the currently available radiological methods cannot clearly differentiate between necrotic tissue and viable tumour. EUS elastography is an ultrasound technique that can grade the hardness of a lesion and classify it as benign, inflammatory or neoplastic as previously reported. This case report of 2 patients shows that using EUS elastography is beneficial in characterizing the nature of the changes occurring to the tumour mass following EUS-RFA of pancreatic tumour.

Comparison of combination therapies in the management of locally advanced pancreatic cancer: Induction chemotherapy followed by irreversible electroporation vs radiofrequency ablation

Background

Locally advanced pancreatic cancer (LAPC) remains a challenge for current treatments. Local destructive therapies, such as irreversible electroporation (IRE) and radiofrequency ablation (RFA), were used more and more frequently in the treatment of LAPC.

Objective

This study aimed to compare the efficacy of IRE with RFA in patients with LAPC.

Methods

From August 2015 to August 2017, 58 LAPC patients after IRE or RFA therapy, which was performed through open approach, were retrospectively reviewed. The survival outcomes after IRE (36 patients) and RFA (18 patients) were compared after propensity score matching (PSM) analysis.

Results

Before PSM analysis, IRE after the induction chemotherapy resulted in significant higher overall survival (OS) rates and progression‐free survival (PFS) rates to RFA (2‐year OS, 53.5% vs 30.8%, P = .013; 2‐year PFS, 28.4% vs 12.1%, P = .043). After PSM analysis, compared with RFA, the survival benefit of IRE was even more obvious, (2‐year OS, 53.5% vs 27.0%, P = .010; 2‐year PFS, 28.4% vs 6.4%, P = .018). For patients with tumor larger than 4 cm, IRE resulted in comparable OS and PFS between RFA and IRE while IRE also achieved better long‐term OS to RFA for those with tumor smaller than 4 cm. Multivariate analysis illustrated that IRE was a favorable prognostic factor in terms of OS and PFS in patients with LAPC.

Conclusions

IRE after induction chemotherapy is superior to RFA after induction chemotherapy for treating LAPC patients while these two therapies have comparable efficacy for tumors which were larger than 4 cm.

Prognostic factor analysis of irreversible electroporation for locally advanced pancreatic cancer - A multi-institutional clinical study in Asia

INTRODUCTION

Irreversible electroporation (IRE) is a modality that utilizes high electric voltage to cause cell apoptosis. IRE has been used to treat locally advanced pancreatic cancer (LAPC). However, studies of IRE via surgical approaches for LAPC are limited. This study aims to analyse the outcomes and related prognostic factors of IRE for Asian patients with LAPC.

MATERIALS AND METHODS

From 2012 to 2017, this prospective trial for using IRE through surgical approaches for LAPC was conducted in 11 medical centres in Asia. All related and treatment outcomes were analysed from a prospective database.

RESULTS

Seventy-four patients were enrolled. Thirty complications occurred in thirteen (17.6%) patients without mortality. The electrode placement direction (anteroposterior vs. craniocaudal, HR = 14.2, p < 0.01) and gastrointestinal invasion (HR = 15.7, p < 0.01) were significant factors for complications. The progression-free survival (PFS) rate in one year, three years, and five years were 69.1%, 48.7%, and 28.8%, and the overall survival (OS) rate in one year, three years, and five years were 97.2%, 53%, and 31.2%. In univariate analysis, the chemotherapy regimen, local tumour recurrence, axial tumour length, tumour volume, and serum carbohydrate antigen 19-9 levels were all significantly associated with PFS and OS. In multivariate analysis, the chemotherapy regimen was the only significant factor associated with PFS and OS. TS-1 (Tegafur, gimeracil, and oteracil) group has superior survival outcome than gemcitabine group.

CONCLUSION

This study showed that combined induction chemotherapy and surgical IRE for LAPC is safe. For well-selected patients, IRE can achieve encouraging survival outcomes.

Ablative, Endovascular, and Biliary Interventions for Patients with Pancreatic Cancer

Interventional radiologists have multiple points of involvement in the treatment and management of patients with pancreatic adenocarcinoma. There is increasing interest in cytoreductive treatment of the primary tumor as well as metastatic disease via arterial and ablative techniques. The focus of this article is on the current evidence for pancreatic irreversible electroporation. For patients undergoing curative surgery or terminal palliation, interventional radiology can manage complications and symptoms. In this article, therapeutic and palliative options in this group of patients including postoperative embolization, biliary drainage, and stent placement are reviewed.

Irreversible Electroporation of the Pancreas

Irreversible electroporation (IRE) is a relatively recent method of ablation. In contrast to many ablation devices that use thermal methods to induce cell death, IRE employs the use of an electric field to cause irreversible permeability of the cell membrane, thus inducing apoptosis. Since its use in the pancreas was first described in 2012, IRE has become established as part of the armamentarium of ablation devices currently available. The crucial advantage of IRE compared with other devices employing thermal ablation is the safety around vital structures such as vessels and ducts. This is especially important in the pancreas due to the close proximity of multiple major vascular structures, biliary ducts, and adjacent gastrointestinal organs. This article will explore the current evidence regarding the use of IRE in the pancreas.

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.

Pancreatic Ultrasound: State of the Art

An ultrasound (US) study is often the first imaging approach in patients with abdominal symptoms or signs related to abdominal diseases, and it is often part of the routine workup. The pancreatic gland, despite its retroperitoneal site, can be efficiently examined with US thanks to advances in US technologies. Nowadays, a pancreatic US study could be considered complete if multiparametric, including the use of Doppler imaging, US elastography, and contrast-enhanced imaging for the study of a pancreatic mass. A complete US examination could contribute to a faster diagnosis, especially if the pancreatic lesion is incidentally detected, addressing second-step imaging modalities correctly.

Treatment of locally advanced pancreatic cancer with irreversible electroporation - a Danish single center study of safety and feasibility

OBJECTIVES

Irreversible electroporation (IRE) is a novel non-thermal ablative technique applied in the treatment of unresectable locally advanced pancreatic cancer (LAPC). This paper reports on the initial experience with IRE of unresectable LAPC in our institution.

METHODS

From October 2013 to March 2018, patients with unresectable LAPC referred for IRE at the Department of Gastrointestinal Surgery, Aalborg University Hospital, were considered for inclusion in the study. Ninety-day morbidity, 30-day mortality, pain score, length of hospital stay (LOS) and overall survival (OS) were recorded.

RESULTS

We included 33 patients receiving 40 IRE ablations in total. The median visual analogue scale (VAS)-score was four (range 0-10) two hours after IRE, and one (range 0-8) eight hours after IRE. The median LOS was one day (range 1-13 days). Post-procedural complications occurred in 21 of 40 ablations (53%), of which eight (20%) were major (Clavien-Dindo grade III or more). A proportion of the observed complications might be attributed to disease progression and not IRE per se. Although not statistically significant, we observed increased severity of complications in tumors above 3.5 cm. The 30-day mortality was 5% (2/40). The median OS was 10.7 months (range 0.6-53.8 months) from the initial IRE procedure, and 18.5 months (range 4.9-65.8 months) from time of diagnosis.

CONCLUSIONS

In our institution, IRE seems as a feasible consolidative treatment of unresectable LAPC with an acceptable safety profile. The oncological outcome of IRE in patients with unresectable LAPC is to be further evaluated in a planned phase 2 clinical trial (CHEMOFIRE-2).

Optimization of an Endoscopic Radiofrequency Ablation Electrode

Radiofrequency ablation (RFA) is an increasingly used, minimally invasive, cancer treatment modality for patients who are unwilling or unable to undergo a major resective surgery. There is a need for RFA electrodes that generate thermal ablation zones that closely match the geometry of typical tumors, especially for endoscopic ultrasound-guided (EUS) RFA. In this paper, the procedure for optimization of an RFA electrode is presented. First, a novel compliant electrode design is proposed. Next, a thermal ablation model is developed to predict the ablation zone produced by an RFA electrode in biological tissue. Then, a multi-objective genetic algorithm is used to optimize two cases of the electrode geometry to match the region of destructed tissue to a spherical tumor of a specified diameter. This optimization procedure is then applied to EUS-RFA ablation of pancreatic tissue. For a target 2.5 cm spherical tumor, the optimal design parameters of the compliant electrode design are found for two cases. Cases 1 and 2 optimal solutions filled 70.9% and 87.0% of the target volume as compared to only 25.1% for a standard straight electrode. The results of the optimization demonstrate how computational models combined with optimization can be used for systematic design of ablation electrodes. The optimization procedure may be applied to RFA of various tissue types for systematic design of electrodes for a specific target shape.

Cooled tip radiofrequency ablation of benign thyroid nodules: preliminary experience with two different devices

Background

Thyroid nodules are very common in general population. Even if benign, they may require a treatment in case of symptoms or cosmetic concerns. In the last years, minimally invasive treatments alternative to surgery have been developed, in particular ultrasound (US) guided radiofrequency ablation (RFA).

Methods

Twenty-four patients (9 males; 15 females; mean age 57.9 years) were treated and divided in two groups (A and B) according to the RFA needle used (18 gauge needle, AMICA; 17 gauge needle, COVIDIEN). Nodules and patients characteristics, together with procedural data were registered pre-treatment and at 1-month follow-up. US visibility of the needle, volume of the nodules, symptoms and cosmetic concerns, complications were registered.

Results

Visibility of the needle was not significantly different in the two groups (P=0.0787). At 1 month the mean volume of the nodules dropped from 37.1 to 25 mL in group A and from 23.2 to 15.4 mL in group B; shrinkage rate (36.9% and 39.5%, respectively) was not significantly different (P=0.3137). Symptoms decreased from 3.1 to 1.4 in group A and from 4 to 1.6 in group B: no significant differences in reductions were observed (P=0.3305). Cosmetic score decreased from 3.7 to 3.4 in group A and from 3.9 to 3.6 in group B: no significant differences in reductions were observed (P=0.96). Total complication rate (18.2% in group A vs. 23.1% in group B) did not showed significant differences (P=0.5049).

Conclusions

The two systems used in our study resulted equivalent in terms of US needle visibility, efficacy, symptom/cosmetic relief, safety. More patients and a longer follow-up are necessary to confirm our results.

Percutaneous microwave thermosphere ablation of pancreatic tumours

Background

In oncologic field, thermo-ablative procedures have spread more and more. Percutaneous microwave ablation (MWA) showed same benefits and some advantages over radiofrequency ablation (RFA). To date, a disadvantage of both was the not totally predictable size and shape of ablation volume. The aim of this study was to assess feasibility and safety of MWA in nonresectable pancreatic head cancer using a new technology of MW with high power (100 W) and frequency of 2,450 MH.

Methods

Five patients with pancreatic head cancer treated with percutaneous MWA under ultrasound guidance were retrospectively reviewed. Mean lesion diameter was 27.8 mm (range, 25-32 mm). Follow-up was performed by CT after 1, 3, 6 and, when possible, 12 months. The shape of the ablation volume was evaluated with multiplanar reformatting (MPR) using roundness index (RI): a value near 1 represents a more spherical ablation zone shape, and a value distant from 1 implies an oval configuration. Ablation and procedure times were registered, together with hospital stay. The feasibility, safety and quality of life (QoL) were reported.

Results

The procedure was feasible in all patients (100%). A spherical shape of ablation zone was achieved in all cases (mean RI =0.97). Mean ablation and procedure time were respectively of 2.48 and 28 minutes. Mean hospital stay was 4 days. No major complications were observed. 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.

Conclusions

Percutaneous MWA is a feasible and safe approach for the palliative treatment of advanced stage tumors of the head of the pancreas, despite its complex anatomic relations. The spherical shape of the ablation volume could be related with an improving of the effectiveness and safety.

The role of irreversible electroporation (IRE) for locally advanced pancreatic cancer: a systematic review of safety and efficacy

OBJECTIVES

Irreversible electroporation (IRE) is a new modality for tumor ablation. Electrodes are placed around the tumor, and a pulsed, direct current with a field strength of 2000 V/cm is delivered. The direct current drives cells into apoptosis and cell death without causing significant heating of the tissues, which spares the extracellular matrix and proteins. The purpose of this review was to evaluate current experience of IRE for the ablation of pancreatic cancer.

MATERIAL AND METHODS

We searched PubMed for all studies of IRE in human pancreatic cancer in English reporting at least 10 patients.

RESULTS

The search yielded 10 studies, comprising a total of 446 patients. Percutaneous IRE was done in 142 patients, while 304 patients were treated during laparotomy. Tumor sizes ranged from median 2.8 to 4.5 cm. Post-procedural complications occurred in 35% of patients, most of them were less severe. Nine patients (2.0%) died after the procedure. The technical success rate was 85-100%. The median recurrence-free survival was 2.7-12.4 months after IRE treatment. The median overall survival was 7-23 months postoperatively. The longest overall survival was noted when IRE was used in conjunction with pancreatic resection.

CONCLUSIONS

IRE seems feasible and safe with a low post-procedural mortality. Further efforts are needed to address patient selection and efficacy of IRE, as well as the use of IRE for 'margin accentuation' during surgical resection.

Immunomodulation after radiofrequency ablation of locally advanced pancreatic cancer by monitoring the immune response in 10 patients

OBJECTIVE/BACKGROUND

RFA of pancreatic cancer has been demonstrated to be feasible and safe with a positive impact on survival. The aim was to investigate whether an immune reaction is activated after locally advanced pancreatic cancer (LAPC) ablation.

METHODS

Peripheral Blood samples were obtained preoperatively and on post-operative days 3-30. Evaluated parameters were: cells [CD4⁺, CD8⁺ and activated subsets, T-Reg, Monocytes, myeloid and plasmocytoid Dendritic cells (mDC and pDC)] and cytokines [Interleukin (IL)-6, Stromal-cells derived factor (SDF)-1, IL-1β, Tumour-Necrosis Factor (TNF)-α, Interferon (IFN)-γ, Vascular Endothelial Growth Factor (VEGF), chemokine (C-C motif) ligand 5 (CCL-5), Transforming-Growth Factor (TGF)-β].

RESULTS

Ten patients were enrolled. CD4⁺, CD8⁺ and TEM increased from day 3 suggesting the activation of the adaptive response. Immunosuppressive T-Reg cells were stable despite the possibility that laparotomy and heating might favour their expansion. Myeloid DCs, that present tumour-associated antigens, increased at day 30. RFA dramatically increased circulating IL-6 at day 3 but this decreased to baseline by day 30, consistent with the supposed anti-tumour effect. RFA did not significantly modulate essential chemokines, such as CCL-5 and SDF1, VEGF, TGF-β and TNF-α, that favour tumour-growth by sustaining cancer angiogenesis and fuelling tumour-associated inflammation.

CONCLUSIONS

This study provides the first evidence of RFA-based immunomodulation in LAPC. We observed a general activation of adaptive response along with a decrease of immunosuppression. Furthermore, most cells showed prolonged activation some weeks after the procedure, suggesting true immunomodulation rather than a normal inflammatory response.

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

AIM

The objective of this study was to evaluate the efficacy of percutaneous radiofrequency ablation of locally advanced pancreatic cancer located in the pancreatic body.

MATERIALS AND METHODS

Patients with biopsy-proven locally advanced pancreatic adenocarcinoma were considered for percutaneous radiofrequency ablation. Postprocedural computed tomography studies and Ca19.9 tumor marker evaluation were performed at 24 hours and 1 month. At computed tomography, treatment effect was evaluated by excluding the presence of complications. The technical success of the procedure is defined at computed tomography as the achievement of tumoral ablated area.

RESULTS

Twenty-three patients have been included in the study. Five of the 23 patients were excluded. At computed tomography, the mean size of the intralesional postablation necrotic area was 32 mm (range: 15-65 mm). Technical success of the procedure has been obtained in 16 (93%) of the 18 cases. None of the patients developed postprocedural complications. Mean Ca19.9 serum levels 1 day before, 1 day after, and 1 month after the procedure were 285.8 U/mL (range: 16.6-942.0 U/mL), 635.2 U/mL (range: 17.9-3368.0 U/mL), and 336.0 U/mL (range: 7.0-1400.0 U/mL), respectively. Follow-up duration was less than 6 months for 11 patients and more than 6 months for 7 patients. At the time of the draft of this article, the mean survival of the patients included in the study was 185 days (range: 62-398 days).

CONCLUSION

Percutaneous radiofrequency ablation of locally advanced adenocarcinoma has a high technical success rate and is effective in cytoreduction both at imaging and laboratory controls.

Theoretical investigation of transgastric and intraductal approaches for ultrasound-based thermal therapy of the pancreas

Background

The goal of this study was to theoretically investigate the feasibility of intraductal and transgastric approaches to ultrasound-based thermal therapy of pancreatic tumors, and to evaluate possible treatment strategies.

Methods

This study considered ultrasound applicators with 1.2 mm outer diameter tubular transducers, which are inserted into the tissue to be treated by an endoscopic approach, either via insertion through the gastric wall (transgastric) or within the pancreatic duct lumen (intraductal). 8 patient-specific, 3D, transient, biothermal and acoustic finite element models were generated to model hyperthermia (n = 2) and ablation (n = 6), using sectored (210°–270°, n = 4) and 360° (n = 4) transducers for treatment of 3.3–17.0 cm³ tumors in the head (n = 5), body (n = 2), and tail (n = 1) of the pancreas. A parametric study was performed to determine appropriate treatment parameters as a function of tissue attenuation, blood perfusion rates, and distance to sensitive anatomy.

Results

Parametric studies indicated that pancreatic tumors up to 2.5 or 2.7 cm diameter can be ablated within 10 min with the transgastric and intraductal approaches, respectively. Patient-specific simulations demonstrated that 67.1–83.3% of the volumes of four sample 3.3–11.4 cm³ tumors could be ablated within 3–10 min using transgastric or intraductal approaches. 55.3–60.0% of the volume of a large 17.0 cm³ tumor could be ablated using multiple applicator positions within 20–30 min with either transgastric or intraductal approaches. 89.9–94.7% of the volume of two 4.4–11.4 cm³ tumors could be treated with intraductal hyperthermia. Sectored applicators are effective in directing acoustic output away from and preserving sensitive structures. When acoustic energy is directed towards sensitive structures, applicators should be placed at least 13.9–14.8 mm from major vessels like the aorta, 9.4–12.0 mm from other vessels, depending on the vessel size and flow rate, and 14 mm from the duodenum.

Conclusions

This study demonstrated the feasibility of generating shaped or conformal ablative or hyperthermic temperature distributions within pancreatic tumors using transgastric or intraductal ultrasound.

[The role of 3D-CT in surgery for pancreatic ductal adenocarcinoma: post-processing and tissue volume calculation]

AIM

To define the indications for pancreatoduodenectomy using 3D CT-imaging, to calculate the volume of damaged and intact tissues and to determine type of surgery depending on severity of disease in case of ductal pancreatic adenocarcinoma.

MATERIAL AND METHODS

Retrospective analysis of CT-scans of 30 patients with ductal pancreatic adenocarcinoma was performed. In groups 1 and 2 by 15 patients total pancreatectomy and pancreatoduodenectomy were made respectively. All patients underwent contrast-enhanced CT examination (Brilliance iCT, Phillips) followed post-processing on Brilliance Workspace Portal platform. All data were assessed by two reviewers.

RESULTS

In group 1 CT volume of the tumor was 24±19 cm3 (32% of total pancreas), in group 2 - 9.8±6 cm3 (16% of total pancreas). CT-volume of celiacomesenteric arteries and portal system was 25.8±10 mm/59.5±18.9 mm and 23.3±6/49.9±14.7 mm in groups 1 and 2 respectively. Greater volume of tumor was significantly associated with increased portal system (p<0.03). Sensitivity, specificity and accuracy of determining of tumor location were increased up to 94%, 50% and 80% respectively in group 1. There were no cases of wrong localization in group 2. Data of both reviewers were similar.

CONCLUSION

Total pancreatectomy is advisable for pancreatic adenocarcinoma if its volume is over 31.8% of total pancreas according to 3D CT-scans. 3D-modeling improves preoperative assessment of resectability, accuracy of determining of tumor localization and identifying vascular invasion.

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.

Variation of tumoral marker after radiofrequency ablation of pancreatic adenocarcinoma

BACKGROUND

To evaluate the correlation between variations of CA 19.9 blood levels and the entity of necrosis at CT after radiofrequency ablation (RFA) of unresectable pancreatic adenocarcinoma.

METHODS

In this study, from June 2010 to February 2014, patients with diagnosis of unresectable and not metastatic pancreatic ductal adenocarcinoma, expressing tumor marker CA 19.9, treated with RFA procedure were included. All these patients underwent RFA. CT study was performed 1 week after RFA. The dosage of CA 19.9 levels was performed 1 month after RFA. Features of necrosis at CT, as mean entity, density and necrosis percentages compared to the original lesion, were evaluated and compared by using t-test with CA 19.9 blood levels variations after RFA procedure.

RESULTS

In this study were included 51 patients with diagnosis of unresectable and not metastatic pancreatic ductal adenocarcinoma, expressing tumor marker CA 19.9, treated with RFA procedure and with CT study and CA 19.9 available for analysis. After the procedure, CA 19.9 blood levels reduced in 24/51 (47%), remained stable in 10/51 (20%) and increased in 17/51 (33%). In patients with CA 19.9 levels reduced, the tumor marker were reduced less than 20% in 4/24 (17%) and more than 20% in 20/24 (83%); instead the tumor marker were reduced less than 30% in 8/24 (33%) and more than 30% in 16/24 (67%). At CT scan necrotic area density difference was not statistically significant. Also there was no statistically significant difference among the mean area, the mean volume and the mean ablation volume in percentage related to the treated tumor among the three different groups of patients divided depending on the CA 19.9 blood levels. But a tendency to a statistically significant difference was found in comparing the mean percentage of ablation volume between two subgroups of patients with a decrease of CA 19.9 levels with less or more than 20% reduction of tumor markers and between two subgroups with less or more than 30% reduction of CA 19.9 levels.

CONCLUSIONS

RFA of unresectable pancreatic adenocarcinoma induces reduction of CA 19.9 blood levels in about half of the cases.

Endoscopic ultrasound-guided radiofrequency ablation of the pancreas: An experimental study with pathological correlation

Background:

The treatment of pancreatic cancer represents a major objective in clinical research, as it still remains the fourth leading cause of cancer deaths among men and women, with approximately 6% of all cancer-related deaths.

Materials and Methods:

We studied the assessment of an endoscopic ultrasound (EUS)-guided radiofrequency ablation (RFA) probe through a 19G needle in order to achieve a desirable necrosis area in the pancreas. Radiofrequency ablation of the head of the pancreas was performed on 10 Yorkshire pigs with a weight between 25 kg and 35 kg and a length of 40-70 cm. Using an EUS-guided RFA experimental probe, we ablated an area of 2-3 cm width. The biological samples were harvested after 3 days and 5 days and necropsy was performed 1 week after the procedure.

Results:

All pigs showed no significant change regarding their behavior and no signs of complication was encountered. Blood analysis revealed increased values of amylase, alkaline phosphatase, and gamma-glutamyl transpeptidase on the 3rd day but a decrease on the 5th day. After necropsy and isolation of the pancreas, the ablated area was easily found, describing a solid necrosis. The pathological examination revealed a coagulative necrosis area with minimal invasion and inflammatory tissue at about 2 cm surrounding the lesion.

Conclusion:

EUS-RFA is a feasible technique and might represent a promising therapy for the future treatment of pancreatic cancer. However, further studies are necessary to investigate EUS-guided RFA as an option for palliation in pancreatic cancer until it can be successfully used in human patients.

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.

Outcome of superior mesenteric-portal vein resection during pancreatectomy for borderline ductal adenocarcinoma: results of a prospective comparative study

BACKGROUND

Approximately 20 % of patients affected by pancreatic ductal adenocarcinoma are amenable to surgical resection. Several tumours are reported as "borderline resectable" because of their proximity to the major vessels. In the effort to achieve a radical tumour removal, vein resection has been proposed, but its oncological benefits remain debated.

METHODS

Our aim is to investigate morbidity, mortality and survival after pancreatectomy with vein resection.

RESULTS

Forty patients underwent pancreatectomy and vein resection (group A), and 20 patients (group B) underwent bilio-enteric and/or gastro-entero bypass. In group A, cancer vein invasion was microscopically proven in 14 cases (35 %). Vein infiltration, tumour differentiation and node-positive disease were not adverse prognostic variables. No difference in survival was seen over a 1-year follow-up. After this period, group A showed significant survival benefits with a longer stabilisation of the disease (p = 0.005). Tumour-free resection margins and adjuvant chemoradiotherapy were the most important prognostic factors (p < 0.05).

CONCLUSIONS

Suspicion of vein infiltration should not be a contraindication to resection. Pancreatectomy can be safely performed with an acceptable morbidity and better survival trend.

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.

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.

Triple approach strategy for patients with locally advanced pancreatic carcinoma

BACKGROUND

Radiofrequency ablation (RFA) is a relatively new technique, applied to metastatic solid tumours which, in recent studies, has been shown to be feasible and safe on locally advanced pancreatic carcinoma (LAPC). RFA can be combined with radio-chemotherapy (RCT) and intra-arterial plus systemic chemotherapy (IASC). The aim of this study was to investigate the impact on the prognosis of a multimodal approach to LAPC and define the best timing of RFA.

METHODS

This is a retrospective observational study of patients who have consecutively undergone RFA associated with multiple adjuvant approaches.

RESULTS

Between February 2007 and December 2011, 168 consecutive patients were treated by RFA, of which 107 were eligible for at least 18 months of follow-up. Forty-seven patients (group 1) underwent RFA as an up-front treatment and 60 patients as second treatment (group 2) depending on clinician choice. The median overall survival (OS) of the whole series was 25.6 months: 14.7 months in the group 1 and 25.6 months in the group 2 (P = 0.004). Those patients who received the multimodal treatment (RFA, RCT and IASC-triple approach strategy) had an OS of 34.0 months.

CONCLUSIONS

The multimodal approach seems to be feasible and associated with an improved longer survival rate.

Short term chemotherapy followed by radiofrequency ablation in stage III pancreatic cancer: results from a single center

BACKGROUND

Neo-adjuvant chemotherapy (CHT) has gained increasing importance in resectable and borderline resectable pancreatic cancer leading to a better performing surgery when we look at negative resection margins and selection of patients with less aggressive disease. We apply this principle to patients with Stage III (LAC) pancreatic cancer undergoing RFA and try to select patients who may benefit from a local treatment.

METHODS

All patients affected by LAC were treated with RFA for a stable disease after a short CHT. Postoperative morbidity and mortality were evaluated together with overall survival (OS) and disease specific survival (DSS).

RESULTS

We consecutively treated 57 patients affected by LAC. Median duration of CHT before RFA was 5 months. The postoperative mortality rate was zero. Overall morbidity was 14 % with RFA-related morbidity of 3.5 %. The OS and DSS were 19 months and when compared to a similar population who received RFA as up front treatment, there was no difference.

CONCLUSIONS

Our results do not support the adoption of a short CHT as a way to identify patients to treat with RFA with the most benefit. Based on this and by knowing the role of immune modulation after RFA and its specific involvement in pancreatic carcinoma, we can propose RFA as upfront treatment.

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.

Combined modality treatment for patients with locally advanced pancreatic adenocarcinoma

BACKGROUND

Radiofrequency ablation (RFA) is an emerging treatment for patients with locally advanced pancreatic carcinoma, and can be combined with radiochemotherapy and intra-arterial plus systemic chemotherapy.

METHODS

This observational study compared two groups of patients with locally advanced pancreatic carcinoma treated with either primary RFA (group 1) or RFA following any other primary treatment (group 2).

RESULTS

Between February 2007 and May 2010, 107 consecutive patients were treated with RFA. There were 47 patients in group 1 and 60 in group 2. Median overall survival was 25·6 months. Median overall survival was significantly shorter in group 1 than in group 2 (14·7 versus 25·6 months; P = 0·004) Patients treated with RFA, radiochemotherapy and intra-arterial plus systemic chemotherapy (triple-approach strategy) had a median overall survival of 34·0 months.

CONCLUSION

RFA after alternative primary treatment was associated with prolonged survival. This was further extended by use of a triple-approach strategy in selected patients. Further evaluation of this approach seems warranted.

Percutaneous irreversible electroporation of surgically unresectable pancreatic cancer: a case report

The present report describes a case of percutaneous irreversible electroporation (IRE) in a 78-year-old man with surgically unresectable stage III (tumor/node/metastasis stages, T4N0M0) pancreatic adenocarcinoma. Two ablations were performed for a 4.1-cm mass encasing the celiac and superior mesenteric artery. At 3 months, a solitary liver metastasis developed, which was treated with radiofrequency ablation followed by gemcitabine chemotherapy. At 6-month follow-up, magnetic resonance imaging demonstrated no residual disease and a decreasing cancer antigen 19-9 level. Percutaneous IRE shows promise as a feasible and potentially safe method for local tumor control in patients with surgically unresectable disease.