Percutaneous image guided electrochemotherapy of hepatocellular carcinoma: technological advancement

Treatment of vulvar cancer recurrence with electrochemotherapy: a case-control study

BACKGROUND

Electrochemotherapy (ECT) is a combined treatment method based on electroporation and simultaneous chemotherapy. In cases where radiotherapy has previously been used, surgery is often the only treatment option for vulvar cancer recurrence with potential resection of clitoris, vagina, urethra or anal sphincter. The unique advantage of ECT is its selectivity for cancer cells while sparing the surrounding healthy tissue. The aim of the study was to compare the ECT treatment of vulvar cancer recurrence for non-palliative purposes with surgical treatment.

MATERIALS AND METHODS

Eleven patients with single vulvar cancer recurrence were treated with ECT and followed up for 12 months. As a control group, 15 patients with single vulvar cancer recurrence were treated with wide local excision. The following data were collected, analyzed and compared: Age, body mass index, comorbidities, histological type, location and size of vulvar cancer recurrence, treatment history, details of procedures and hospital stay.

RESULTS

The probability curves for local tumor control did not differ between the ECT group and the surgical group (p = 0.694). The mean hospital stay and the mean duration of procedure were statistically significantly shorter in the ECT group (p < 0.001). There were no statistically significant differences between the ECT and surgical groups in terms of mean body mass index, associated diseases, previous treatments, presence of lichen sclerosus, p16 status, gradus, anatomical site of the tumor, and type of anesthesia.

CONCLUSION

In this case-control study, treatment of vulvar cancer recurrence with ECT for non-palliative purposes was comparable to surgical treatment in terms of effectiveness. The results need to be confirmed in larger randomized trials.

The equivalence of different types of electric pulses for electrochemotherapy with cisplatin - an in vitro study

BACKGROUND

Electrochemotherapy (ECT) is a treatment involving the administration of chemotherapeutics drugs followed by the application of 8 square monopolar pulses of 100 μs duration at a repetition frequency of 1 Hz or 5000 Hz. However, there is increasing interest in using alternative types of pulses for ECT. The use of high-frequency short bipolar pulses has been shown to mitigate pain and muscle contractions. Conversely, the use of millisecond pulses is interesting when combining ECT with gene electrotransfer for the uptake of DNA-encoding proteins that stimulate the immune response with the aim of converting ECT from a local to systemic treatment. Therefore, the aim of this study was to investigate how alternative types of pulses affect the efficiency of the ECT.

MATERIALS AND METHODS

We performed in vitro experiments, exposing Chinese hamster ovary (CHO) cells to conventional ECT pulses, high-frequency bipolar pulses, and millisecond pulses in the presence of different concentrations of cisplatin. We determined cisplatin uptake by inductively coupled plasma mass spectrometry and cisplatin cytotoxicity by the clonogenic assay.

RESULTS

We observed that the three tested types of pulses potentiate the uptake and cytotoxicity of cisplatin in an equivalent manner, provided that the electric field is properly adjusted for each pulse type. Furthermore, we quantified that the number of cisplatin molecules, resulting in the eradication of most cells, was 2-7 × 107 per cell.

CONCLUSIONS

High-frequency bipolar pulses and millisecond pulses can potentially be used in ECT to reduce pain and muscle contraction and increase the effect of the immune response in combination with gene electrotransfer, respectively.

Intraoperative electrochemotherapy of the posterior resection surface after pancreaticoduodenectomy: Preliminary results of a hybrid approach treatment of pancreatic cancer

BACKGROUND

Despite extensive research in recent decades, pancreatic cancer continues to be among the most lethal forms of cancer, with no substantial increase in survival rates. Local recurrences account for approximately 30 per cent of all disease recurrences. With the intent to improve survival, we designed a novel, hybrid treatment strategy consisting of surgical resection and additional intraoperative electrochemotherapy of the posterior resection surface. We present the study protocols and preliminary findings of a prospective pilot study investigating this treatment approach.

METHODS

Consenting patients with resectable pancreatic head ductal adenocarcinoma who met the inclusion criteria were enrolled in the study. After surgical resection, electrochemotherapy with bleomycin was performed using plate electrodes to cover the area between anatomical landmarks.

RESULTS

Electrochemotherapy of the posterior resection surface was feasible in all 7 patients. We observed pancreatic fistula grade B in only one patient; all other noted complications were Clavien-Dindo grade 2 or less. The hospital mortality was 0%.

CONCLUSIONS

Our preliminary results suggest that a hybrid approach combining surgery with intraoperative electrochemotherapy is safe and feasible.

Comparison of Nucleosome, Ferritin and LDH Levels in Blood with Clinical Response before and after Electrochemotherapy Combined with IL-12 Gene Electrotransfer for the Treatment of Mast Cell Tumours in Dogs

Electrochemotherapy (ECT) in combination with the gene electrotransfer of interleukin 12 (IL-12 GET) has been successfully used in veterinary medicine for the treatment of mast cell tumours (MCT), but the biomarkers that could predict response to this treatment have not yet been investigated. The aim of this study was to determine the plasma nucleosome and serum ferritin concentrations, as well as the lactate dehydrogenase (LDH) activity, in the serum of treated patients before and one and six months after treatment to evaluate their utility as potential biomarkers that could predict response to the combined treatment. The study was conducted in 48 patients with a total of 86 MCTs that we treated with the combined treatment. The blood samples used for analysing the potential predictive biomarkers were taken before treatment and one and six months after treatment, when the response to treatment was also assessed. The Nu. Q® Vet Cancer Test, the Canine Ferritin ELISA Kit, and the RX Daytona+ automated biochemical analyser were used to analyse the blood samples. The results showed that the plasma nucleosome concentration (before treatment (BT): 32.84 ng/mL (median); one month after treatment (1 M AT): 58.89 ng/mL (median); p = 0.010) and serum LDH activity (BT: 59.75 U/L (median); 1 M AT: 107.5 U/L (median); p = 0.012) increased significantly one month after treatment and that the increase correlated significantly with the presence of a more pronounced local reaction (necrosis, swelling, etc.) at that time point for both markers (nucleosome: BT (necrosis): 21.61 ng/mL (median); 1 M AT (necrosis): 69.92 ng/mL (median), p = 0.030; LDH: BT (necrosis): 54.75 U/L (median); 1 M AT (necrosis): 100.3 U/L (median), p = 0.048). Therefore, both the plasma nucleosome concentration and serum LDH activity could serve as early indicators of the effect of the treatment. In this context, the serum ferritin concentration showed no significant predictive potential for treatment response (p > 0.999 for all comparisons). In conclusion, this study provides some new and important observations on the use of predictive biomarkers in veterinary oncology. Furthermore, it emphasises the need for the continued identification and validation of potential predictive biomarkers in dogs with MCT and other malignancies undergoing ECT treatment in combination with IL-12 GET to ultimately improve treatment outcomes.

Optimal Dosing and Patient Selection for Electrochemotherapy in Solid Abdominal Organ and Bone Tumors

The primary aim of this study was to analyze studies that use electrochemotherapy (ECT) in "deep-seated" tumors in solid organs (liver, kidney, bone metastasis, pancreas, and abdomen) and understand the similarities between patient selection, oncologic selection, and use of new procedures and technology across the organ systems to assess response rates. A literature search was conducted using the term "Electrochemotherapy" in the title field using publications from 2017 to 2023. After factoring in inclusion and exclusion criteria, 29 studies were analyzed and graded based on quality in full. The authors determined key patient and oncologic selection characteristics and ECT technology employed across organ systems that yielded overall responses, complete responses, and partial responses of the treated tumor. It was determined that key selection factors included: the ability to be administered bleomycin, life expectancy greater than three months, unrespectability of the lesion being treated, and a later stage, more advanced cancer. Regarding oncologic selection, all patient cohorts had received chemotherapy or surgery previously but had disease recurrence, making ECT the only option for further treatment. Lastly, in terms of the use of technology, the authors found that studies with better response rates used the ClinporatorTM and updated procedural guidelines by SOP. Thus, by considering patient, oncologic, and technology selection, ECT can be further improved in treating lesions in solid organs.

Recent Advancements in Electroporation Technologies: From Bench to Clinic

Over the past decade, the increased adoption of electroporation-based technologies has led to an expansion of clinical research initiatives. Electroporation has been utilized in molecular biology for mammalian and bacterial transfection; for food sanitation; and in therapeutic settings to increase drug uptake, for gene therapy, and to eliminate cancerous tissues. We begin this article by discussing the biophysics required for understanding the concepts behind the cell permeation phenomenon that is electroporation. We then review nano- and microscale single-cell electroporation technologies before scaling up to emerging in vivo applications.

Effects of Electrochemotherapy on Immunologically Important Modifications in Tumor Cells

Electrochemotherapy (ECT) is a clinically acknowledged method that combines the use of anticancer drugs and electrical pulses. Electrochemotherapy with bleomycin (BLM) can induce immunogenic cell death (ICD) in certain settings. However, whether this is ubiquitous over different cancer types and for other clinically relevant chemotherapeutics used with electrochemotherapy is unknown. Here, we evaluated in vitro in the B16-F10, 4T1 and CT26 murine tumor cell lines, the electrochemotherapy triggered changes in the ICD-associated damage-associated molecular patterns (DAMPs): Calreticulin (CRT), ATP, High Mobility Group Box 1 (HMGB1), and four immunologically important cellular markers: MHCI, MHC II, PD-L1 and CD40. The changes in these markers were investigated in time up to 48 h after ECT. We showed that electrochemotherapy with all three tested chemotherapeutics induced ICD-associated DAMPs, but the induced DAMP signature was cell line and chemotherapeutic concentration specific. Similarly, electrochemotherapy with CDDP, OXA or BLM modified the expression of MHC I, MHC II, PD-L1 and CD40. The potential of electrochemotherapy to change their expression was also cell line and chemotherapeutic concentration specific. Our results thus put the electrochemotherapy with clinically relevant chemotherapeutics CDDP, OXA and BLM on the map of ICD inducing therapies.

Safety and Feasibility of Analgosedation for Electrochemotherapy of Liver Lesions

Interventional Oncology treatments grant low-risk mini-invasive alternatives to surgery for cancer patients. Percutaneous ablative therapies represent a cornerstone for treatment of liver cancer patients. Among these, a newly emerging one is represented by electrochemotherapy. Improvements in analgesia and sedation can nowadays offer optimal support for ablative procedures, serving as a valid alternative to general anesthesia. The intention of this retrospective monocentric study is to report our preliminary experience on feasibility and safety of electrochemotherapy for treatment of complex liver tumors unfit for thermal ablation, using analgosedation instead of general anesthesia. Five patients were enrolled in the study, undergoing electrochemotherapy under analgosedation. Mean procedural time and hospitalization time were recorded. Immediate post-procedural cone-beam CT showed complete coverage of the lesion without complications. One-month CT examination showed an overall response rate of 100% (four complete responses, one partial response). Electrochemotherapy under analgosedation seems to be a safe, feasible, and effective option for liver cancer patients not amenable to other ablative techniques.

Invasive and non-invasive electrodes for successful drug and gene delivery in electroporation-based treatments

Electroporation is an effective physical method for irreversible or reversible permeabilization of plasma membranes of biological cells and is typically used for tissue ablation or targeted drug/DNA delivery into living cells. In the context of cancer treatment, full recovery from an electroporation-based procedure is frequently dependent on the spatial distribution/homogeneity of the electric field in the tissue; therefore, the structure of electrodes/applicators plays an important role. This review focuses on the analysis of electrodes and in silico models used for electroporation in cancer treatment and gene therapy. We have reviewed various invasive and non-invasive electrodes; analyzed the spatial electric field distribution using finite element method analysis; evaluated parametric compatibility, and the pros and cons of application; and summarized options for improvement. Additionally, this review highlights the importance of tissue bioimpedance for accurate treatment planning using numerical modeling and the effects of pulse frequency on tissue conductivity and relative permittivity values.

Percutanous Electrochemotherapy (ECT) in Primary and Secondary Liver Malignancies: A Systematic Review

The aim of the study was to analyse papers describing the use of Electrochemotherapy (ECT) in local treatment of primary and secondary liver tumours located at different sites and with different histologies. Other Local Ablative Therapies (LAT) are also discussed. Analyses of these papers demonstrate that ECT use is safe and effective in lesions of large size, independently of the histology of the treated lesions. ECT performed better than other thermal ablation techniques in lesions > 6 cm in size and can be safely used to treat lesions distant, close, or adjacent to vital structures. ECT spares vessel and bile ducts, is repeatable, and can be performed between chemotherapeutic cycles. ECT can fill the gap in local ablative therapies due to being lesions too large or localized in highly challenging anatomical sites.

Advances of Electroporation-Related Therapies and the Synergy with Immunotherapy in Cancer Treatment

Electroporation is the process of instantaneously increasing the permeability of a cell membrane under a pulsed electric field. Depending on the parameters of the electric pulses and the target cell electrophysiological characteristics, electroporation can be either reversible or irreversible. Reversible electroporation facilitates the delivery of functional genetic materials or drugs to target cells, inducing cell death by apoptosis, mitotic catastrophe, or pseudoapoptosis; irreversible electroporation is an ablative technology which directly ablates a large amount of tissue without causing harmful thermal effects; electrotherapy using an electric field can induce cell apoptosis without any aggressive invasion. Reversible and irreversible electroporation can also activate systemic antitumor immune response and enhance the efficacy of immunotherapy. In this review, we discuss recent progress related to electroporation, and summarize its latest applications. Further, we discuss the synergistic effects of electroporation-related therapies and immunotherapy. We also propose perspectives for further investigating electroporation and immunotherapy in cancer treatment.

Laparoscopic electrochemotherapy for the treatment of hepatocellular carcinoma: Technological advancement

Electrochemotherapy is an effective treatment modality for hepatocellular carcinoma (HCC). Electrochemotherapy for HCC was initially used in the setting of open surgery. Recently, with the development of newer electrodes, percutaneous approaches have also been performed. However, laparoscopic application of electrochemotherapy for HCC has not yet been described. Two patients with unresectable HCC were enrolled in the study. The first patient was not suitable for the percutaneous approach because the tumor was located close to the gallbladder. He also had symptomatic gallstones. The second patient had HCC in close proximity to the stomach and was therefore not suitable for percutaneous access or any other ablative technique. Thus, the laparoscopic approach was chosen, using newly developed Stinger electrodes for the application of electric pulses. After intravenous administration of bleomycin, several sets of electric pulses were delivered to the whole tumor mass in both patients. Ultrasonographically, the coverage of the whole tumor was verified, as described previously. Cholecystectomy was also performed in the first patient. Follow-up abdominal computed tomography showed a complete response of the treated lesions in both patients. Minimally invasive laparoscopic electrochemotherapy is safe, feasible and effective method for the treatment of HCC. It could be used in patients in whom the percutaneous approach is unsafe (proximity to other organs) and in patients with concomitant symptomatic gallstones in whom cholecystectomy is already indicated. This technological approach thus allows broader and minimally invasive clinical applicability of electrochemotherapy.

Electrochemotherapy for solid tumors: literature review and presentation of a novel endoscopic approach

BACKGROUND

Electrochemotherapy (ECT) is a minimally invasive and safe treatment gaining positive and long-lasting antitumoral results that are receiving the attention of the scientific community. It is a local treatment that combines the use of electroporation and the administration of cytotoxic drugs to induce cell death in the target tissue. ECT is largely used for the treatment of cutaneous and subcutaneous lesions, and good results have been reported for the treatment of deep visceral tumors. The latest literature review is provided. Moreover, in line with its development for the treatment of visceral tumors in this article, we describe a novel approach of ECT: endoscopic treatment of colorectal cancer. Endoscopic ECT application was combined with systemic chemotherapy in the treatment of obstructing rectal cancer without prospective surgery. A good response after ECT was described: concentric involvement of the rectum was reduced, and no stenosing lesions were detected.

CONCLUSIONS

Clinical studies have demonstrated that ECT is a very effective treatment for tumors of different histologic types and localizations. Endoscopic treatment for gastrointestinal cancer is an innovative application of ECT. The combination of systemic treatment and ECT was safe and highly effective in the treatment of colorectal cancer, especially when obstructive, giving the patient a significant gain in quality of life.

Update on Percutaneous Local Ablative Procedures for the Treatment of Hepatocellular Carcinoma

BACKGROUND

 Hepatocellular carcinoma (HCC) is the fifth most common tumor worldwide. Because many hepatocellular carcinomas are already unresectable at the time of initial diagnosis, percutaneous tumor ablation has become established in recent decades as a curative therapeutic approach for very early (BCLC 0) and early (BCLC A) HCC. The aim of this paper is to provide a concise overview of the percutaneous local ablative procedures currently in use, based on their technical characteristics as well as clinical relevance, taking into account the current body of studies.

MATERIALS AND METHODS

 The literature search included all original papers, reviews, and meta-analyses available via MEDLINE and Pubmed on the respective percutaneous ablation procedures; the primary focus was on randomized controlled trials and publications from the last 10 years.

RESULTS AND CONCLUSIONS

 Radiofrequency ablation (RFA) and microwave ablation (MWA) are well-established procedures that are considered equal to surgical resection in the treatment of stage BCLC 0 and A HCC with a diameter up to 3 cm due to their strong evidence in international and national guidelines. For tumors with a diameter between 3 and 5 cm, the current S3 guidelines recommend a combination of transarterial chemoembolization (TACE) and thermal ablation using RFA or MWA as combination therapy is superior to thermal ablation alone in tumors of this size and shows comparable results to surgical resection in terms of overall survival. Alternative, less frequently employed thermal procedures include cryotherapy (CT) and laser ablation (LA). Non-thermal procedures include irreversible electroporation (IRE), interstitial brachytherapy (IBT), and most recently, electrochemotherapy (ECT). Due to insufficient evidence, these have only been used in individual cases and within the framework of studies. However, the nonthermal methods are a reasonable alternative for ablation of tumors adjacent to large blood vessels and bile ducts because they cause significantly less damage to these structures than thermal ablation methods. With advances in the technology of the respective procedures, increasingly good evidence, and advancements in supportive techniques such as navigation devices and fusion imaging, percutaneous ablation procedures may expand their indications for the treatment of larger and more advanced tumors in the coming years.

KEY POINTS

· RFA and MWA are considered equal to surgical resection as a first-line therapy for the curative treatment of stage BCLC 0 and A HCCs with a diameter of up to 3 cm.. · For HCCs with a diameter between 3 and 5 cm, a combination of TACE and RFA or MWA is recommended. This combination therapy yields results comparable to those of surgical resection in terms of overall survival.. · Due to insufficient evidence, alternative ablation methods have only been used in individual cases and within the framework of studies. However, nonthermal methods, such as IRE, IBT, and, most recently, ECT, are a reasonable alternative for ablation of HCCs adjacent to large blood vessels and bile ducts because they cause significantly less damage to these structures than thermal ablation methods..

CITATION FORMAT

· Luerken L, Haimerl M, Doppler M et al. Update on Percutaneous Local Ablative Procedures for the Treatment of Hepatocellular Carcinoma. Fortschr Röntgenstr 2022; DOI: 10.1055/a-1768-0954.

Sunitinib potentiates the cytotoxic effect of electrochemotherapy in pancreatic carcinoma cells

BACKGROUND

One of the new treatment options for unresectable locally advanced pancreatic cancer is electrochemotherapy (ECT), a local ablative therapy that potentiates the entry of chemotherapeutic drugs into the cells, by the application of an electric field to the tumor. Its feasibility and safety were demonstrated in preclinical and clinical studies; however, there is a lack of preclinical studies assessing the actions of different drugs used in ECT, their mechanisms and interactions with other target drugs that are used in clinical practice.

MATERIALS AND METHODS

The aim of the study was to determine the cytotoxicity of two chemotherapeutic drugs usually used in ECT (bleomycin and cisplatin) in the BxPC-3 human pancreatic carcinoma cell line and evaluate the interactions of ECT with the targeted drug sunitinib. First, the cytotoxicity of ECT using both chemotherapeutics was determined. In the next part, the interactions of ECT and sunitinib were evaluated through determination of combined cytotoxicity, sunitinib targets and kinetics of cell death.

RESULTS

The results demonstrate that ECT is effective in pancreatic cancer cell line, especially when bleomycin is used, with the onset of cell death in the first hours after the treatment, reaching a plateau at 20 hours after the treatment. Furthermore, we provide the rationale for combining ECT with bleomycin and the targeted drug sunitinib to potentiate cytotoxicity. The combined treatment of sunitinib and ECT was synergistic for bleomycin only at the highest used concentration of bleomycin 0.14 μM, whereas with lower doses of bleomycin, this effect was not observed. The interaction of ECT and treatment with sunitinib was confirmed by course of the cell death, also indicating on synergism.

CONCLUSIONS

ECT and sunitinib combined treatment has clinical potential, and further studies are warranted.

Percutaneous electrochemotherapy in primary and secondary liver malignancies - local tumor control and impact on overall survival

Background

Local nonsurgical tumor ablation currently represents a further option for the treatment of patients with liver tumors or metastases. Electrochemotherapy (ECT) is a welcome addition to the portfolio of local therapies. A retrospective analysis of patients with liver tumors or metastases treated with ECT is reported. Attention is given to the safety and efficacy of the treatment over time.

Patients and methods

Eighteen consecutive patients were recruited with measurable liver tumors of different histopatologic origins, mainly colorectal cancer, breast cancer, and hepatocellular cancer. They were treated with percutaneous ECT following the standard operating procedures (SOP) for ECT under general anaesthesia and muscle relaxation. Treatment planning was performed based on MRI preoperative images. The follow-up assessment included contrast-enhanced MR within at least 1–3 months after treatment and then after 5, 7, 9, 12, and 18 months until progression of the disease or death.

Results

Only mild or moderate side effects were observed after ECT. The objective response rate was 85.7% (complete response 61.9%, partial 23.8%), the mean progression-free survival (PFS) was 9.0 ± 8.2 months, and the overall survival (OS) was 11.3 ± 8.6 months. ECT performed best (PFS and OS) in lesions within 3 and 6 cm diameters (p = 0.0242, p = 0.0297)_. The effectiveness of ECT was independent of the localization of the lesions: distant, close or adjacent to vital structures. Progression-free survival and overall survival were independent of the primary histology considered.

Conclusions

Electrochemotherapy provides an effective valuable option for the treatment of unresectable liver metastases not amenable to other ablative techniques.

New era of electrochemotherapy in treatment of liver tumors in conjunction with immunotherapies

Electrochemotherapy is a local ablative therapy that increases the cytotoxicity of either bleomycin or cisplatin by applying electric pulses (electroporation) to tumors. It has already been widely used throughout Europe for the treatment of various types of human and veterinary cutaneous tumors, with an objective response rate ranging from 70%-90%, depending on the tumor histotype. Recently, electrochemotherapy was introduced for the treatment of primary liver tumors, such as hepatocellular carcinoma (HCC). The complete response rate was 85% per treated lesion, with a durable response. Therefore, electrochemotherapy could become a treatment of choice for HCC, especially after achieving a transition from an open surgery approach to a percutaneous approach that uses dedicated electrodes. Electrochemotherapy elicits a local immune response and can be considered an in situ vaccination. HCC, among others, is a potentially immunogenic tumor; thus, electrochemotherapy could boost adjuvant immunotherapy to achieve a better and longer-lasting antitumor response. Therefore, therapeutic strategies that combine electrochemotherapy with immune checkpoint inhibitors or adjuvant treatment with cytokines are indicated for HCC. Immunogene therapy using electroporation as a delivery system for plasmid DNA coding for interleukin-12 is a highly promising approach. This electroporation approach has shown efficacy in preclinical settings and veterinary oncology and is awaiting translation for the treatment of liver tumors, i.e., HCC.

Fabrication of Fe3O4@PVA microspheres by one-step electrospray for magnetic resonance imaging during transcatheter arterial embolization

Magnetic resonance imaging (MRI) has attracted increasing attention as a feasible alternative or adjunctive imaging modality for X-ray digital subtraction angiography because of the high tissue resolution and non-ionization radiation. In this study, a one-step electrospray method was developed to fabricate PVA microspheres encapsulated with in situ synthesized Fe₃O₄ nanoparticles. Fe₃O₄@PVA microspheres were mono-dispersed black spheres with a wide range of sizes (262-958 µm). The in situ-synthesized Fe₃O₄ nanoparticles were used as the contrast agent of MRI and the cross-linkers of PVA matrixes for the embolization purpose. In vivo evaluation of renal arteries of normal rabbits showed that Fe₃O₄@PVA microspheres had good embolic effect and enhanced capability of MRI. In vitro and in vivo biosafety assessment confirmed that Fe₃O₄@PVA microspheres had favorable biocompatibility. The DOX-loaded Fe₃O₄@PVA microspheres showed a typical drug-sustained release profile. These results suggest that the prepared DOX-loaded Fe₃O₄@PVA microspheres have the function of MRI, embolotherapy and chemotherapy. We expect our study could provide a simple and useful approach for the systematic design, fabrication, and application of a new type of magnetic microspheres as a triple-functional embolic agent for the development of MRI-guided TACE. STATEMENT OF SIGNIFICANCE: Due to the low tissue resolution and hazardous ionization radiation of X-ray digital subtraction angiography, it is beneficial to study MR imaging embolic microspheres for the development of MRI-guided TACE. In this study, a one-step electrospray method was firstly developed to fabricate PVA microspheres encapsulated with in situ synthesized Fe₃O₄ nanoparticles. Then, chemotherapeutic agent (DOX), contrast media of MRI (Fe₃O₄) and embolic agent (PVA matrix) were combined together in one body (DOX-loaded Fe₃O₄@PVA microspheres) to achieve the triple effects of chemotherapy, MR imaging and embolization. This triple-functional embolic agent offers potential for the future development of MRI-guided TACE.

Stereotactic Percutaneous Electrochemotherapy as Primary Approach for Unresectable Large HCC at the Hepatic Hilum

Electrochemotherapy (ECT) is a novel non-thermal ablative technique that combines chemotherapy and the application of electric pulses for reversible cell membrane electroporation. This method was recently performed in the treatment of deep-seated liver tumors during open surgery but experience about percutaneous ECT is rare and further developments like combination of percutaneous ECT with stereotactic navigated devices may be very promising. We report on a case of a 4.7 × 4.5 × 3.5 cm unresectable HCC at the hepatic hilum adjacent to the major vessels and the bile duct that was successfully treated using percutaneous ECT in combination with stereotactic navigation. Follow-up imaging 6 weeks and 6 months after ECT showed complete response.

Gene electrotransfer of IL-2 and IL-12 plasmids effectively eradicated murine B16.F10 melanoma

Gene therapy has become an important approach for treating cancer, and electroporation represents a technology for introducing therapeutic genes into a cell. An example of cancer gene therapy relying on gene electrotransfer is the use of immunomodulatory cytokines, such as interleukin 2 (IL-2) and 12 (IL-12), which directly stimulate immune cells at the tumour site. The aim of our study was to determine the effects of gene electrotransfer with two plasmids encoding IL-2 and IL-12 in vitro and in vivo. Two different pulse protocols, known as EP1 (600 V/cm, 5 ms, 1 Hz, 8 pulses) and EP2 (1300 V/cm, 100 µs, 1 Hz, 8 pulses), were assessed in vitro for application in subsequent in vivo experiments. In the in vivo experiment, gene electrotransfer of pIL-2 and pIL-12 using the EP1 protocol was performed in B16.F10 murine melanoma. Combined treatment of tumours using pIL2 and pIL12 induced significant tumour growth delay and 71% complete tumour regression. Furthermore, in tumours coexpressing IL-2 and IL-12, increased accumulation of dendritic cells and M1 macrophages was obtained along with the activation of proinflammatory signals, resulting in CD4 + and CD8 + T-lymphocyte recruitment and immune memory development in the mice. In conclusion, we demonstrated high antitumour efficacy of combined IL-2 and IL-12 gene electrotransfer protocols in low-immunogenicity murine B16.F10 melanoma.

Literature Review and Our Experience With Bleomycin-Based Electrochemotherapy for Cutaneous Vulvar Metastases From Endometrial Cancer

Endometrial carcinoma is the most common gynecological malignancy and the fifth most common malignancy in women. The worldwide incidence is 15.9 new cases per 100,000 women per year, and the incidence in Europe is 22.7 new cases. Minority of cases are diagnosed at an advanced stage of the disease. Cutaneous metastases are very rare with a prevalence of 0.8%. If cutaneous metastases are present, the prognosis is poor with an overall survival of up to 12 months. In this review, we presented clinical data on treatment of gynecological cancers with electrochemotherapy, with focus on treatment of cutaneous vulvar metastases from endometrial cancer. Further, we present our data on the case of a 64-year-old woman with recurrent endometrial adenocarcinoma with vulvar skin metastases. Treatment of endometrial carcinoma metastases is multimodal with surgery, chemotherapy, radiotherapy and hormone treatment. There is still no consensus about the specific treatment of cutaneous metastases from endometrial cancer, in particular in order to release symptoms. Electrochemotherapy may be a treatment option to reduce pain and bleeding and a safe option to treat multiple skin metastases.

Biological factors of the tumour response to electrochemotherapy: Review of the evidence and a research roadmap

The beneficial effects of electrochemotherapy (ECT) for superficial tumours and, more recently, deep-seated malignancies in terms of local control and quality of life are widely accepted. However, the variability in responses across histotypes needs to be explored. Currently, patient selection for ECT is based on clinical factors (tumour size, histotype, and exposure to previous oncological treatments), whereas there are no biomarkers to predict the response to treatment. In this field, two major areas of investigation can be identified, i.e., tumour cell characteristics and the tumour microenvironment (vasculature, extracellular matrix, and immune infiltrate). For each of these areas, we describe the current knowledge and discuss how to foster further investigation. This review aims to provide a summary of the currently used guiding clinical factors and delineates a research roadmap for future studies to identify putative biomarkers of response to ECT. These biomarkers may allow researchers to improve ECT practice by customising treatment parameters, manipulating the tumour and its microenvironment, and exploring novel therapeutic combinations.

A Prospective Phase II Study Evaluating Intraoperative Electrochemotherapy of Hepatocellular Carcinoma

The aim of this clinical study was to investigate the effectiveness and long-term safety of electrochemotherapy as an emerging treatment for HCC in patients not suitable for other treatment options. A prospective phase II clinical study was conducted in patients with primary HCC who were not suitable for other treatment options according to the Barcelona Clinic Liver Cancer classification. A total of 24 patients with 32 tumors were treated by electrochemotherapy. The procedure was effective, feasible, and safe with some procedure-related side effects. The responses of the 32 treated nodules were: 84.4% complete response (CR), 12.5% partial response (PR), and 3.1% stable disease (SD). The treatment was equally effective for nodules located centrally and peripherally. Electrochemotherapy provided a durable response with local tumor control over 50 months of observation in 78.0% of nodules. The patient responses were: 79.2% CR and 16.6% PR. The median progression-free survival was 12 months (range 2.7-50), and the overall survival over 5 years of observation was 72.0%. This prospective phase II clinical study showed that electrochemotherapy was an effective, feasible, and safe option for treating HCC in patients not suitable for other treatment options.