Comparison of bleomycin polidocanol foam vs electrochemotherapy combined with polidocanol foam for treatment of venous malformations.

OBJECTIVE: This study aims to investigate the difference in safety and efficacy between two treatments for venous malformations (VMs), electrochemotherapy combined with polidocanol foam (ECP) and bleomycin polidocanol foam (BPF), providing alternative therapies for VMs. METHODS: We conducted a retrospective review of 152 patients with VMs treated with ECP and BPF. Pre- and post-treatment magnetic resonance images (MRIs) were collected, and clinical follow-up assessments were performed. Imaging results were used to calculate lesion volume changes. Clinical outcomes included changes in pain and improvements in perceived swelling. Patients were followed up at 1 week and 6 months after surgery. All emerging complications were documented in detail. RESULTS: Of the 152 patients, 87 (57.2%) received BPF treatment, and 65 (42.8%) received ECP treatment. The most common location of VMs was the lower extremities (92/152; 60.2%), and the most common symptom was pain (108/152; 71.1%). Forty-three patients had previously undergone therapy in the BPF group (43/87; 49.4%), whereas 30 patients had received prior treatment in the ECP group (30/65; 46.2%). The study found that the percentage of lesion volume reduction in the BPF group was not significantly different from that in the ECP group (75.00% ± 17.85% vs 74.69% ± 8.48%; P = .899). ECP was more effective when the initial lesion volume was greater than 30 mL (67.66% ± 12.34% vs 73.47% ± 8.00%; P = .048). Patients treated with BPF had significantly less posttreatment pain than those treated with ECP, in different baseline lesion size. In the overall sample, pain relief was significantly higher in the BPF group than in the ECP group (4.21 ± 1.19 vs 3.57 ± 0.76; P = .002). However, there was no difference in pain relief between the two groups for the treatment of initially large VMs (4.20 ± 0.94 vs 3.70 ± 0.87; P = .113). The ECP group was significantly more likely to develop hyperpigmentation (5/87; 5.75% vs 11/65; 16.92%; P = .026) and swelling (9/87; 10.34% vs 16/65; 24.62%; P = .019) 1 week after surgery than the BPF group. CONCLUSIONS: Our study demonstrates that both BPF and ECP are effective treatments for VMs, with BPF being a safer option. ECP is a better choice for patients with the initial lesion volume greater than 30 mL, but it is more likely to lead to early swelling and hyperpigmentation.

Effectiveness and tolerance of electrochemotherapy as palliative therapy for patients with head and neck cancer and malignant melanoma and its relation to early skin reaction.

OBJECTIVES: To evaluate the efficacy and tolerance after the electrochemotherapy treatment for local therapy of cutaneous and subcutaneous metastases of head-and-neck tumors and malignant melanoma refractory to standard therapies, mainly in neck metastasis of squamous cell carcinoma. And, to evaluate the relation of this response according to the skin reaction (healing with ulcer or dry crust). METHODS: prospective pase II, observational clinical study of 56 patients with metastases of head-and-neck squamous cell carcinoma (n=13), papillary thyroid carcinoma (n=4), adenoid cystic carcinoma of parotid gland (n=1) or malignant melanoma (n=37, 5 in head). Patients were treated by electrochemotherapy (application of electrical pulses into the tumor) after the administration of a single intravenous dose of bleomycin. Kaplan-Meier curves were performed. The statistical significance was evaluated using log-rank test; p-value of less than 0.05 was considered as significant. RESULTS: Overall clinical response was observed in 47 patients (84%). Local side effects were mild in all the patients. Ten patients (76.9%) with neck metastasis of squamous cell carcinoma had some degree of response, but only in one was complete. Patients even with only partial response had a higher overall survival than patients without response (p= 0.02). Most of the patients with squamous cell carcinoma had diminution of pain and anxiety. Response rate and overall survival was higher in MM patients (86.5%) than in squamous cell cancer patients (76.9%) (p= 0.043). The healing process (dry crust/ulcer) was not associated with the overall survival (p= 0.86). CONCLUSIONS: Electrochemotherapy is associated a higher overall survival and diminution of pain and anxiety. Therefore, it is an option as palliative treatment for patients with neck metastasis of squamous cell carcinoma refractory to other therapies or even as a concomitant treatment with newer immunotherapies. The type of healing of the surgical wound could not be associated with a higher rate of response or survival. LEVEL OF EVIDENCE: III.

Cutaneous and subcutaneous Kaposi's sarcoma lesions treated with electrochemotherapy.

BACKGROUND AND OBJECTIVES: Kaposi's sarcoma (KS) is a locally aggressive mesenchymal tumor that involves the lymphovascular system, with a tendency to become multifocal. Electrochemotherapy (ECT) is considered a valuable treatment option in selected patients with cutaneous and subcutaneous KS lesions. METHODS: We report a retrospective study that included 14 classic and endemic KS patients that underwent ECT sessions for the treatment of KS cutaneous and subcutaneous lesions at our institution. RESULTS: According to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 criteria, our patients had an overall response rate (ORR) of 100% to the ECT treatment. A complete response (CR) was obtained in 92.8% of patients after one or more ECT sessions. Only one patient had a progressive disease (PD). The treatment was well tolerated with a low complication rate, mainly transitory local pain or skin ulceration. CONCLUSIONS: ECT represents a locoregional therapy for containment and symptomatic control of classic and endemic KS cutaneous and subcutaneous lesions. Further studies including different subtypes of KS patients should also be performed.

Electrochemotherapy combined with immunotherapy - a promising potential in the treatment of cancer.

Electrochemotherapy is a novel, locoregional therapy that is used to treat cutaneous and deep-seated tumors. The electric pulses used in electrochemotherapy increase the permeability of the cell membranes of the target lesion and thus enhance the delivery of low-permeant cytotoxic drugs to the cells, leading to their death. It has also been postulated that electrochemotherapy acts as an in situ vaccination by inducing immunogenic cell death. This in turn leads to an enhanced systemic antitumor response, which could be further exploited by immunotherapy. However, only a few clinical studies have investigated the role of combined treatment in patients with melanoma, breast cancer, hepatocellular carcinoma, and cutaneous squamous cell carcinoma. In this review, we therefore aim to review the published preclinical evidence on combined treatment and to review clinical studies that have investigated the combined role of electrochemotherapy and immunotherapy.

Novel electroporation-based treatments for breast cancer.

Breast cancer (BC) is the most common cancer in women, and its incidence is increasing every year. Current treatment is based on surgical resection, chemotherapy (CT), radiotherapy, and hormone therapy (HT). Unfortunately, these methods are ineffective and are associated with a wide range of side effects (e.g., nausea, hair loss and fertility disorders). Electrochemotherapy (ECT), which exposes tumor cells to electric pulses (known as electroporation (EP)) in combination with cytostatic drugs, enables the reduction of cytotoxic drug doses while increasing their efficacy. Electroporation-based treatment methods are applied in breast carcinoma and are the subject of intensive research globally. Irreversible EP has shown promising therapeutic potential in the absence of cytotoxic drugs, as has EP associated with molecules such as calcium ions that are already present in the human body. The application of EP-based methods seems to be a safer and more effective treatment for BC in vitro and in vivo. Indeed, they have found applications in the treatment of BC and its metastases. Moreover, their palliative effects have also been established, and pain reduction has been noted in patients.

Electrochemotherapy in Translational Medicine: From Veterinary Experience to Human Oncology.

Electrochemotherapy (ECT) is a tumor treatment that, through the application of electric pulses with suitable amplitude and waveforms, favors the systemic or local delivery of chemotherapy agents. This procedure significantly increases the permeability of cancer cells to anticancer drugs, making them more effective and allowing their use at lower doses with less morbidity for patients. Its use in veterinary oncology is consolidated and it is currently adopted as first-line treatment for different cancers with successful results. In human oncology, ECT use is mainly in the treatment of cutaneous tumors and for the palliation of cutaneous metastases of malignant tumors. A standard operating procedure has been formulated. Currently, several preclinical and phase I and II studies are under way involving various cancers in humans to better define the efficacy and tolerability of this therapy. This review summarizes the state of the art of ECT in veterinary and human oncology, describing the most significant results achieved to date.

Electrochemotherapy of skin metastases from malignant melanoma: a PRISMA-compliant systematic review.

The main treatment of MM metastases are systemic therapies, surgery, limb perfusion, and intralesional talimogene laherparepvec. Electrochemotherapy (ECT) is potentially useful also due to the high response rates recorded in cancers of any histology. No randomized studies comparing ECT with other local therapies have been published on this topic. We analyzed the available evidence on efficacy and toxicity of ECT in this setting. PubMed, Scopus, and Cochrane databases were screened for paper about ECT on MM skin metastases. Data about tumor response, mainly in terms of overall response rate (ORR), toxicity (both for ECT alone and in combination with systemic treatments), local control (LC), and overall survival (OS) were collected. The methodological quality was assessed using a 20-item validated quality appraisal tool for case series. Overall, 18 studies were included in our analysis. In studies reporting "per patient" tumor response the pooled complete response (CR) was 35.7% (95%CI 26.0-46.0%), and the pooled ORR was 80.6% (95%CI 68.7-90.1%). Regarding "per lesion" response, the pooled CR was 53.5% (95%CI 42.1-64.7%) and the pooled ORR was 77.0% (95%CI 56.0-92.6%). One-year LC rate was 80%, and 1-year OS was 67-86.2%. Pain (24.2-92.0%) and erythema (16.6-42.0%) were the most frequent toxicities. Two studies reported 29.2% and 41.6% incidence of necrosis. ECT is effective in terms of tumor response and tolerated in patients with skin metastases from MM, albeit with a wide variability of reported results. Therefore, prospective trials in this setting are warranted.

Prospective cohort study by InspECT on safety and efficacy of electrochemotherapy for cutaneous tumors and metastases depending on ulceration.

BACKGROUND: Electrochemotherapy (ECT) is an effective local treatment for cutaneous tumors. The aim of this study was to compare the effectiveness of ECT in ulcerated vs. non-ulcerated tumors and investigate the effect on tumor-associated symptoms. METHODS: Twenty cancer centers in the International Network for Sharing Practices on Electrochemotherapy (InspECT) prospectively collected data. ECT was performed following ESOPE protocol. Response was evaluated by lesion size development. Pain, symptoms, performance status (ECOG-Index) and health status (EQ-5D questionnaire) were evaluated. RESULTS: 716 patients with ulcerated (n = 302) and non-ulcerated (n = 414) cutaneous tumors and metastases were included (minimum follow-up of 45 days). Non-ulcerated lesions responded to ECT better than ulcerated lesions (complete response 65 % vs. 51 %, p = 0.0061). Only 38 % (115/302) with ulcerated lesions before ECT presented with ulcerated lesions at final follow-up. Patients with ulcerated lesions reported higher pain and more severe symptoms compared to non-ulcerated lesions, which significantly and continuously improved following ECT. In non-ulcerated lesions however, pain spiked during the treatment. No serious adverse events were reported. CONCLUSIONS: ECT is a safe and effective local treatment for cutaneous tumors. While ECT improves symptoms especially in patients with ulcerated lesions, data suggest the implementation of a perioperative pain management in non-ulcerated lesions during ECT.

Electrochemotherapy as palliative treatment in patients with recurrent and/or metastatic head and neck tumours: features analysis for an early determination of the partial responsive patients.

OBJECTIVE: The aim of this study was to identify features mainly involved in determining the partial response (PR) to the Electrochemotherapy (ECT) in patients with recurrent and/or metastatic head and neck (H&N) tumor; the identified features were also used in a decision chart in order to provide the clinician with a support tool in deciding further therapies. PATIENTS AND METHODS: 131 patients (186 treatment sessions) with recurrent and/or metastatic H&N neoplasm were subjected to ECT. Treatment response was evaluated based on Response Evaluation Criteria in Solid Tumors (RECIST) v. 1.1 two months after the ECT. The grade of bleeding and pain before, at the end and one week after ECT treatment were evaluated. Univariate and multivariate analysis were performed to identify features involved in determining the patient PR. RESULTS: In the context of the univariate analysis, tumor size significantly influenced the response to ECT, with higher PR rate of 58.3%: 28 among 48 patients with lesion size ≤ 3 centimeters (p-value < 0.001 at Chi-square test). Pain and bleeding pre-treatment were positively correlated to PR (p-value < 0.001 at Chi-square test). A difference in the current flowing in the tissue during treatment was also observed in partially responsive patients, where the median current value (6.6 A) was higher than that achieved in patients that did not show PR (3.3 A). In the context of the multivariate analysis, the best performances are achieved with the BART method (accuracy of 84%). The main clinical factors to predict the partial response, among investigated features, that have shown to be considered were the pain value felt before performing the treatment and the median current delivered during the ECT treatment. A decision-making support tool to predict the patient prognosis in terms of response rate could be represented by the decision tree obtained with CART algorithm, where a pain pre-treatment more than 5 and a median delivered current not less than 2.8 A led to the prediction a partial responsive patient with an accuracy of 75%. CONCLUSIONS: The study confirmed that ECT is an interesting antitumoral therapy in advanced chemo- and radio-refractory H&N neoplasms, able to reduce frequent symptoms and to improve the quality of life. Pain pre-treatment and delivered current are the most important variables when predicting the partial response of patients.

Electrochemotherapy Is Effective in the Treatment of Bone Metastases.

Bone metastases induce pain, risk of fracture, and neural compression, and reduced mobility and quality of life. Electrochemotherapy (ECT) is a minimally invasive local treatment based on a high-voltage electric pulse combined with an anticancer drug. Preclinical and clinical studies have supported the use of ECT in patients with metastatic bone disease, demonstrating that it does not damage the mineral structure of the bone and its regenerative capacity, and that is feasible and efficient for the treatment of bone metastases. Since 2009, 88 patients with bone metastasis have received ECT at the Rizzoli Institute. 2014 saw the start of a registry of patients with bone metastases treated with ECT, whose data are recorded in a shared database. We share the Rizzoli Institute experience of 38 patients treated with ECT for a bone metastasis, excluding patients not included in the registry (before 2014) and those treated with bone fixation. Mean follow-up was 2 months (1-52). Response to treatment using RECIST criteria was 29% objective responses, 59% stable disease, and 16% progressive disease. Using PERCIST, the response was 36% OR, 14% SD, and 50% PD with no significant differences between the two criteria. A significant decrease in pain and better quality of life was observed at FU.

Neurological Complications After Electrochemotherapy Treatment in the Head and Neck Area.

BACKGROUND/AIM: Electrochemotherapy (ECT) is a predominately palliative treatment for cutaneous metastases where an electric field is used to increase the intracellular accumulation of a chemotherapeutic drug (bleomycin or cisplatin). ECT induces a strong anti-vascular effect and endothelial cells seem especially vulnerable. To date, almost no neurological and/or cerebrovascular complications after ECT treatment have been published. In this paper two such cases are reported. CASE REPORT: A seizure in a man treated with ECT for a basal cell carcinoma in the temporal region and a fatal ischemic stroke in a woman treated for cutaneous metastases in the neck are reported. In both cases a causal relationship to ECT treatment was strongly suspected. CONCLUSION: ECT in the head and neck can potentially cause severe neurological complications. Ultrasound is recommended for ECT treatment in the neck.

Effects of calcium electroporation, electrochemotherapy, and irreversible electroporation on quality of life and progression-free survival in patients with pancreatic cancer: IREC clinical study.

BACKGROUND: According to the National Cancer Registry, 3486 people (1744 men and 1742 women) were diagnosed with pancreatic adenocarcinoma in Poland in 2018, resulting in 4908 deaths (2396 men and 2512 women). The only chance of successful treatment is through surgical resection, which is possible in only 20-30% of patients (stage I, II and some stage III cases).The remaining 70-80% of patients are those with stage III and IV disease, for whom resection is not possible. Mean survival in these patients is approx. 10.4 months (stage III). In the recent decade, an innovative method called electroporation, which involves destabilization of the cell membrane, has been established. This process can be reversible (RE) or irreversible (IRE), and leads to cell death. The ability to change membrane permeability has led to the development of novel methods involving electrochemotherapy (ECT) and calcium electroporation (CaEP) to treat solid tumors. OBJECTIVES: In this study, both ECT and CaEP will be used to treat pancreatic cancer patients with poor prognosis. For each patient, the best "therapeutic moment" for the procedure will be selected based on the therapeutic protocol. MATERIAL AND METHODS: Patients will receive reversible and irreversible electroporation (control arm-group A), CaEP (active arm-group B), or ECT with intravenous and intratumoral administration of bleomycin (active arm-group C) randomized 1:1:1. RESULTS: The primary endpoints will be progression-free survival (PFS) and patients' quality of life (QOL) assessed using the EORTC-PAN 26 scale. Secondary endpoints will be patient overall survival (OS), body weight, pain level, and levels of biomarkers such as Ca 19-9. CONCLUSION: The Irreversible Electroporation, ELectrochemotherapy and Calcium electroporation (IREC) study is necessary to examine the safety and efficiency of irreversible electroporation, electrochemotherapy and calcium electroporation in pancreatic cancer treatment.

The Role of Electrochemotherapy in Curative Treatment of Head and Neck Cancer and Advanced Skin Cancer: A Need for New Treatment Protocols?

BACKGROUND/AIM: Electrochemotherapy (ECT) is a cancer treatment modality where the efficacy of a chemotherapeutic agent is enhanced by an electrical field. It is an established palliative treatment for cutaneous metastases but its role in curative treatment remains mostly undetermined. Studies have previously reported that ECT can be a safe curative treatment in both skin cancer and oral cavity cancer. The primary aim of this case study was to report the long-term results of ECT in curative treatment of four patients with skin or oral cavity cancer. The study also compares two different ECT treatment protocols. PATIENTS AND METHODS: Three patients with oral cavity cancer and one patient with skin cancer were included. One patient had a primary oral tongue cancer and the others had persistent/recurrent tumors after previous treatment. They were treated with ECT either as a primary, adjuvant or salvage treatment with curative intent. The median follow-up period was 60 months. RESULTS: There was one case of local recurrence after treatment in the follow-up period. In the other three patients, no recurrence was recorded. There was one serious adverse airway event. There was a significant difference in the bleomycin dose between the two studied protocols, especially for large tumors. CONCLUSION: ECT can be a safe mono-modality and adjuvant curative treatment in advanced skin cancer and primary and recurrent oral cavity cancer.

Operating procedures for electrochemotherapy in bone metastases: Results from a multicenter prospective study on 102 patients.

INTRODUCTION: Bone metastases are frequent in patients with cancer. Electrochemotherapy (ECT) is a minimally invasive treatment. Preclinical and clinical studies supported the use of ECT in patients with metastatic bone disease (MBD). The purposes of this multicentre study are to confirm the safety and efficacy of ECT, and to identify appropriate operating procedures in different MBD conditions. MATERIALS AND METHODS: 102 patients were treated in 11 Centres and recorded in the REINBONE registry (a shared database protected by security passwords): clinical and radiological information, ECT session, adverse events, response, quality of life indicators and duration of follow-up were registered. RESULTS: 105 ECT sessions were performed (one ECT session in 99 patients, two ECT sessions in 3 patients). 24 patients (23.5%) received a programmed intramedullary nail after ECT, during the same surgical procedure. Mean follow-up was 5.9 ± 5.1 months (range 1.5-52). The response to treatment by RECIST criteria was 40.4% objective responses, 50.6% stable disease and 9% progressive disease. According to PERCIST criteria the response was: 31.4% OR; 51.7% SD, 16.9% PD with no significant differences between the 2 criteria. Diagnosis of breast cancer and ECOG values 0-1 were significantly associated to objective response. A significant decrease in pain intensity and significant better quality of life was observed after ECT session at follow-up. CONCLUSION: The results are encouraging on pain and tumour local control. ECT proved to be an effective and safe treatment for MBD and it should be considered as an alternative treatment as well as in combination with radiation therapy.

The role of electrochemotherapy with intratumoral bleomycin for early tongue carcinoma.

BACKGROUND: The role of electrochemotherapy (ECT) using intratumoral bleomycin and electroporation as a first line treatment for oral tongue carcinoma has not been defined. AIMS/OBJECTIVES: To evaluate the method of ECT in oral tongue carcinoma. MATERIAL AND METHODS: Twenty-one successive patients with primary T1-T2 oral cancer predominantly of the oral tongue underwent either ECT (test; n = 9), or standard surgical resection and reconstruction (control; n = 12). Outcome variables were: local recurrence rates, 10-year-survival, adverse events, treatment cost, and quality of life. RESULTS: The 10-year local recurrence rate (44.4%) was higher and the tumour-specific survival rate (55.6%) was lower in the ECT group compared to the control group (17% and 91.6%, respectively). Postoperative haemorrhage, dysphagia, and pain were more frequent in ECT patients, treatment time was shorter, but treatment cost was higher. Quality of life was not improved by ECT. CONCLUSIONS AND SIGNIFICANCE: Our results indicate that ECT seems not as suitable for the treatment of early tongue cancer as it is for neoplastic and metastatic skin lesions and less favourable than standard surgical therapy.

Bleomycin electrosclerotherapy in therapy-resistant venous malformations of the body.

OBJECTIVE: Bleomycin is one of the most commonly used agents in sclerotherapy for slow-flow vascular malformations worldwide. However, its efficiency remains unknown. The objective of the present study was to assess whether reversible electroporation combined with bleomycin would increase the sclerotherapy effect in patients with previously unsuccessfully treated venous malformations (VMs). METHODS: We performed, to the best of our knowledge, the first retrospective observational case series from January 2019 to January 2020 of 17 patients (20 lesions) with symptomatic VMs, who had previously undergone at least two unsuccessful invasive treatments. Reversible electroporation was performed with various electrodes and directly injected bleomycin. All patient records, magnetic resonance imaging data, documentation of previous treatments, and data regarding the intervention, complications, and clinical symptoms were analyzed. RESULTS: The 17 VM patients (mean age, 20.8 ± 8.2 years; 9 females) had previously undergone an average of 4.2 invasive treatments. These patients had subsequently undergone 22 electrosclerotherapy sessions of 20 lesions. The median dose of bleomycin was 3 mg. The median magnetic resonance imaging-derived lesion volume before treatment was 24.9 cm3, which had decreased by 86% to 3.5 cm3 after treatment. After 3.7 months, eight patients were asymptomatic without residual symptoms and nine patients showed improvement. CONCLUSIONS: Bleomycin electrosclerotherapy appears to be an effective therapy for patients with VMs resistive to previous invasive therapy. Because of the small sample size and short follow-up period, our results should be examined further using a larger patient population.

Outcomes of older adults aged 90 and over with cutaneous malignancies after electrochemotherapy with bleomycin: A matched cohort analysis from the InspECT registry.

BACKGROUND: With extending life expectancy, more people are diagnosed with cutaneous malignancies at advanced ages and are offered nonsurgical treatment. We assessed outcomes of the oldest-old adults after electrochemotherapy (ECT). METHODS: The International Network for Sharing Practices of ECT (InspECT) registry was queried for adults aged ≥90 years (ys) with skin cancers/cutaneous metastases of any histotype who underwent bleomycin-ECT (2006-2019). These were subanalysed with patients aged <90 ys after matching 1:2 for tumor location, number, size, histotype, and previous treatments. We assessed ECT modalities, toxicity (CTCAE), response (RECIST), and patient perception (EQ-5D). RESULTS: Sixty-one patients represented the study cohort (median 92 ys, range 92-104), 122 the control group (median 77 ys, range 23-89). Among the oldest-old, 44 patients (72%) had primary/recurrent skin cancers, 17 (28%) cutaneous metastases. Median tumour size was 15 mm (range, 5-450). The oldest-old adults underwent ECT mainly under local/regional anaesthesia (59% vs 39% p = .012). We observed no differences regarding dose and route of chemotherapy (intravenous vs intratumoral, p = .308), electrode geometry (linear vs hexagonal, p = .172) and procedural duration (18 vs 21 min, p = .378). Complete response (57.4 [95%-CI 44.1%-70.0%] vs 64.7% [95%-CI 55.6%-73.2%], p = .222) and 1-year local control (76.7% vs 81.7, p = .092) rates were comparable. Pain and skin hyperpigmentation were mild in both groups. Skin ulceration persisted longer in the oldest-old patients (4.4 vs 2.4 months, p = .008). CONCLUSIONS: The oldest-old adults with cutaneous malignancies undergo ECT most commonly under local/regional anaesthesia with safety profiles and clinical effectiveness similar to their younger counterparts, except in case of ulcerated tumors.

Investigation of safety for electrochemotherapy and irreversible electroporation ablation therapies in patients with cardiac pacemakers.

BACKGROUND: The effectiveness of electrochemotherapy of tumors (ECT) and of irreversible electroporation ablation (IRE) depends on different mechanisms and delivery protocols. Both therapies exploit the phenomenon of electroporation of the cell membrane achieved by the exposure of the cells to a series of high-voltage electric pulses. Electroporation can be fine-tuned to be either reversible or irreversible, causing the cells to either survive the exposure (in ECT) or not (in IRE), respectively. For treatment of tissues located close to the heart (e.g., in the liver), the safety of electroporation-based therapies is ensured by synchronizing the electric pulses with the electrocardiogram. However, the use of ECT and IRE remains contraindicated for patients with implanted cardiac pacemakers if the treated tissues are located close to the heart or the pacemaker. In this study, two questions are addressed: can the electroporation pulses interfere with the pacemaker; and, can the metallic housing of the pacemaker modify the distribution of electric field in the tissue sufficiently to affect the effectiveness and safety of the therapy? RESULTS: The electroporation pulses induced significant changes in the pacemaker ventricular pacing pulse only for the electroporation pulses delivered during the pacing pulse itself. No residual effects were observed on the pacing pulses following the electroporation pulses for all tested experimental conditions. The results of numerical modeling indicate that the presence of metal-encased pacemaker in immediate vicinity of the treatment zone should not impair the intended effectiveness of ECT or IRE even when the casing is in direct contact with one of the active electrodes. Nevertheless, the contact between the casing and the active electrode should be avoided due to significant tissue heating at the site of the other active electrode for the IRE protocol and may cause the pulse generator to fail to deliver the pulses due to excessive current draw. CONCLUSIONS: The observed effects of electroporation pulses delivered in close vicinity of the pacemaker or its electrodes do not indicate adverse consequences for either the function of the pacemaker or the treatment outcome. These findings should contribute to making electroporation-based treatments accessible also to patients with implanted cardiac pacemakers.

Safety and Feasibility of Electrochemotherapy of the Pancreas in a Porcine Model.

OBJECTIVES: The use of thermal ablative therapies in the pancreatic tumors is limited because of the risk of the vessel injury and potential pancreatitis or fistula formation. Electrochemotherapy (ECT) is an ablative therapy with an established role in the treatment of cutaneous and liver tumors. This study was designed to evaluate the safety and feasibility of ECT of the pancreas in a porcine survival model. METHODS: In the first group, 4 animals underwent computed tomography (CT)-guided percutaneous ECT with bleomycin of the pancreatic tail. In the second group (4 animals), the intraoperative ECT with bleomycin of pancreatic tail and head was performed. Animals were followed for 7 days and then killed. Clinical parameters, CT imaging, laboratory, and histologic analysis were performed. RESULTS: All pigs survived the ECT procedure and none of them developed clinical signs of acute pancreatitis or related complications. There were no signs of acute pancreatitis or damage to the large vessels present in the follow-up CT scans. No significant change in laboratory parameters was obtained after procedure. CONCLUSIONS: This study shows that ECT with bleomycin is feasible and safe in the pancreatic parenchyma. Clinical studies are needed to evaluate the efficacy of ECT in pancreatic cancer.