Optimizing patient selection for stereotactic ablative radiotherapy in patients with locally advanced pancreatic cancer after initial chemotherapy - a single center prospective cohort.

Background: The role of stereotactic ablative radiation therapy (SABR) as local treatment option after chemotherapy for locally advanced pancreatic cancer (LAPC) is evolving. However adequate patient selection criteria for SABR in patients with LAPC are lacking. Methods: A prospective institutional database collected data of patients with LAPC treated with chemotherapy, mainly FOLFIRINOX, followed by SABR, which was delivered using magnetic resonance guided radiotherapy, 40 Gy in 5 fractions within two weeks. Primary endpoint was overall survival (OS). Cox regression analyses were performed to identify predictors for OS. Results: Overall, 74 patients were included, median age 66 years, 45.9% had a KPS score of ≥90. Median OS was 19.6 months from diagnosis and 12.1 months from start of SABR. Local control was 90% at one year. Multivariable Cox regression analyses identified KPS ≥90, age <70, and absence of pain prior to SABR as independent favorable predictors for OS. The rate of grade ≥3 fatigue and late gastro-intestinal toxicity was 2.7%. Conclusions: SABR is a well-tolerated treatment in patients with unresectable LAPC following chemotherapy, with better outcomes when applied in patients with higher performance score, age <70 years and absence of pain. Future randomized trials will have to confirm these findings.

Stereotactic ablative radiotherapy or best supportive care in patients with localized pancreatic cancer not receiving chemotherapy and surgery (PANCOSAR): a nationwide multicenter randomized controlled trial according to a TwiCs design.

BACKGROUND: Significant comorbidities, advanced age, and a poor performance status prevent surgery and systemic treatment for many patients with localized (non-metastatic) pancreatic ductal adenocarcinoma (PDAC). These patients are currently treated with 'best supportive care'. Therefore, it is desirable to find a treatment option which could improve both disease control and quality of life in these patients. A brief course of high-dose high-precision radiotherapy i.e. stereotactic ablative body radiotherapy (SABR) may be feasible. METHODS: A nationwide multicenter trial performed within a previously established large prospective cohort (the Dutch Pancreatic cancer project; PACAP) according to the 'Trial within cohorts' (TwiCs) design. Patients enrolled in the PACAP cohort routinely provide informed consent to answer quality of life questionnaires and to be randomized according to the TwiCs design when eligible for a study. Patients with localized PDAC who are unfit for chemotherapy and surgery or those who refrain from these treatments are eligible. Patients will be randomized between SABR (5 fractions of 8 Gy) with 'best supportive care' and 'best supportive care' only. The primary endpoint is overall survival from randomization. Secondary endpoints include preservation of quality of life (EORTC-QLQ-C30 and -PAN26), NRS pain score response and WHO performance scores at baseline, and, 3, 6 and 12 months. Acute and late toxicity will be scored using CTCAE criteria version 5.0: assessed at baseline, day of last fraction, at 3 and 6 weeks, and 3, 6 and 12 months following SABR. DISCUSSION: The PANCOSAR trial studies the added value of SBRT as compared to 'best supportive care' in patients with localized PDAC who are medically unfit to receive chemotherapy and surgery, or refrain from these treatments. This study will assess whether SABR, in comparison to best supportive care, can relieve or delay tumor-related symptoms, enhance quality of life, and extend survival in these patients. TRIAL REGISTRATION: Clinical trials, NCT05265663 , Registered March 3 2022, Retrospectively registered.

Radiofrequency ablation and chemotherapy versus chemotherapy alone for locally advanced pancreatic cancer (PELICAN): study protocol for a randomized controlled trial.

BACKGROUND: Approximately 80% of patients with locally advanced pancreatic cancer (LAPC) are treated with chemotherapy, of whom approximately 10% undergo a resection. Cohort studies investigating local tumor ablation with radiofrequency ablation (RFA) have reported a promising overall survival of 26-34 months when given in a multimodal setting. However, randomized controlled trials (RCTs) investigating the effect of RFA in combination with chemotherapy in patients with LAPC are lacking. METHODS: The "Pancreatic Locally Advanced Unresectable Cancer Ablation" (PELICAN) trial is an international multicenter superiority RCT, initiated by the Dutch Pancreatic Cancer Group (DPCG). All patients with LAPC according to DPCG criteria, who start with FOLFIRINOX or (nab-paclitaxel/)gemcitabine, are screened for eligibility. Restaging is performed after completion of four cycles of FOLFIRINOX or two cycles of (nab-paclitaxel/)gemcitabine (i.e., 2 months of treatment), and the results are assessed within a nationwide online expert panel. Eligible patients with RECIST stable disease or objective response, in whom resection is not feasible, are randomized to RFA followed by chemotherapy or chemotherapy alone. In total, 228 patients will be included in 16 centers in The Netherlands and four other European centers. The primary endpoint is overall survival. Secondary endpoints include progression-free survival, RECIST response, CA 19.9 and CEA response, toxicity, quality of life, pain, costs, and immunomodulatory effects of RFA. DISCUSSION: The PELICAN RCT aims to assess whether the combination of chemotherapy and RFA improves the overall survival when compared to chemotherapy alone, in patients with LAPC with no progression of disease following 2 months of systemic treatment. TRIAL REGISTRATION: Dutch Trial Registry NL4997 . Registered on December 29, 2015. ClinicalTrials.gov NCT03690323 . Retrospectively registered on October 1, 2018.

The treatment and survival of elderly patients with locally advanced pancreatic cancer: A post-hoc analysis of a multicenter registry.

BACKGROUND: The treatment options for patients with locally advanced pancreatic cancer (LAPC) have improved in recent years and consequently survival has increased. It is unknown, however, if elderly patients benefit from these improvements in therapy. With the ongoing aging of the patient population and an increasing incidence of pancreatic cancer, this patient group becomes more relevant. This study aims to clarify the association between increasing age, treatment and overall survival in patients with LAPC. METHODS: Post-hoc analysis of a multicenter registry including consecutive patients with LAPC, who were registered in 14 centers of the Dutch Pancreatic Cancer Group (April 2015-December 2017). Patients were divided in three groups according to age (<65, 65-74 and ≥75 years). Primary outcome was overall survival stratified by primary treatment strategy. Multivariable regression analyses were performed to adjust for possible confounders. RESULTS: Overall, 422 patients with LAPC were included; 162 patients (38%) aged <65 years, 182 patients (43%) aged 65-74 and 78 patients (19%) aged ≥75 years. Chemotherapy was administered in 86%, 81% and 50% of the patients in the different age groups (p<0.01). Median overall survival was 12, 11 and 7 months for the different age groups (p<0.01).Patients treated with chemotherapy showed comparable median overall survival of 13, 14 and 10 months for the different age groups (p=0.11). When adjusted for confounders, age was not associated with overall survival. CONCLUSION: Elderly patients are less likely to be treated with chemotherapy, but when treated with chemotherapy, their survival is comparable to younger patients.

The value of a dedicated multidisciplinary expert panel to assess treatment strategy in patients suffering from colorectal cancer liver metastases.

BACKGROUND: For patients with colorectal cancer liver metastases (CRLM), local treatment is the only treatment with curative intent. The majority of patients with CRLM are however evaluated in multidisciplinary teams of colorectal cancer specialists often lacking expertise in local treatment of liver tumors. The aim of this study was therefore to assess the value of a dedicated multidisciplinary panel consisting of hepatobiliary surgeons and interventional radiologists for patients suffering from liver-only CRLM. METHODS: Patients diagnosed with liver-only CRLM in 2016 were identified in a tertiary referral hospital, and two of the referring hospitals in the Netherlands. Diagnostic imaging was independently reviewed by a panel of four hepatobiliary surgeons and two interventional radiologists to re-evaluate treatment strategy retrospectively. If two or more panelists assessed all lesions eligible for resection and/or ablation, patients were deemed eligible for local treatment with curative intent. Interrater reliability between hepatobiliary surgeons was assessed through intraclass correlation coefficient (ICC) and weighted Cohen's kappa. RESULTS: Diagnostic imaging of 61 patients with liver-only metastases were reviewed. Local treatment strategies appeared feasible in 40/61 (65.6%) patients. Five out of 25 patients (20.0%) initially assigned to systemic therapy were deemed eligible for upfront local treatment with curative intent (p = 0.015). In this subgroup, interrater reliability between hepatobiliary surgeons was substantial (ICC: 0.704, 95% CI: 0.536-0.838, n = 25). CONCLUSION: Assessment of treatment strategy by a dedicated multidisciplinary panel including liver experts may result in an increased number of patients eligible for potentially curative treatment and reduce undertreatment of patients suffering from liver-only CRLM.

Preoperative imaging for colorectal liver metastases: a nationwide population-based study.

BACKGROUND: In patients with colorectal liver metastases (CRLM) preoperative imaging may include contrast-enhanced (ce) MRI and [18 F]fluorodeoxyglucose (18 F-FDG) PET-CT. This study assessed trends and variation between hospitals and oncological networks in the use of preoperative imaging in the Netherlands. METHODS: Data for all patients who underwent liver resection for CRLM in the Netherlands between 2014 and 2018 were retrieved from a nationwide auditing database. Multivariable logistic regression analysis was used to assess use of ceMRI, 18 F-FDG PET-CT and combined ceMRI and 18 F-FDG PET-CT, and trends in preoperative imaging and hospital and oncological network variation. RESULTS: A total of 4510 patients were included, of whom 1562 had ceMRI, 872 had 18 F-FDG PET-CT, and 1293 had combined ceMRI and 18 F-FDG PET-CT. Use of ceMRI increased over time (from 9·6 to 26·2 per cent; P < 0·001), use of 18 F-FDG PET-CT decreased (from 28·6 to 6·0 per cent; P < 0·001), and use of both ceMRI and 18 F-FDG PET-CT 16·9 per cent) remained stable. Unadjusted variation in the use of ceMRI, 18 F-FDG PET-CT, and combined ceMRI and 18 F-FDG PET-CT ranged from 5·6 to 100 per cent between hospitals. After case-mix correction, hospital and oncological network variation was found for all imaging modalities. DISCUSSION: Significant variation exists concerning the use of preoperative imaging for CRLM between hospitals and oncological networks in the Netherlands. The use of MRI is increasing, whereas that of 18 F-FDG PET-CT is decreasing.

ANTECEDENTES: En pacientes con metástasis hepáticas colorrectales (colorrectal liver metastases, CRLM), los estudios de imagen preoperatorios pueden incluir resonancia magnética con contraste (ce)MRI y 18 F-FDG-PET-CT. Este estudio evaluó las tendencias y la variación entre los hospitales y las redes oncológicas en el uso de estudios de imagen preoperatorios en los Países Bajos. MÉTODOS: Todos los pacientes que se sometieron a una resección hepática por CRLM en los Países Bajos entre 2014 y 2018 fueron seleccionados a partir de una base de datos a nivel nacional auditada. El análisis de regresión logística multivariable se utilizó para evaluar el uso de ceMRI, de 18 F-FDG-PET-CT y de ceMRI combinado con 18 F-FDG-PET-CT, así como para determinar las tendencias en los estudios de imagen preoperatorios y las variaciones hospitalarias y de la red oncológica. RESULTADOS: En total, se incluyeron 4.510 pacientes, de los cuales 1.562 se sometieron a ceMRI, 872 a 18 F-FDG-PET-CT y 1.293 a ceMRI combinado con 18 F-FDG-PET-CT. El uso de ceMRI aumentó con el tiempo del 9,6% al 26,2% (P < 0,001), el uso de 18 F-FDG-PET-CT disminuyó (25% a 6,0%, P < 0,001) y el uso de ceMRI y 18 F-FDG-PET- CT (17%) se mantuvo estable. La variación no ajustada entre hospitales en el uso de ceMRI, 18 F-FDG-PET-CT y la combinación de ceMRI y 18 F-FDG-PET-CT oscilaba del 5% al 10%. Después de la corrección por case-mix, la variación hospitalaria y de la red oncológica persistía en todas las pruebas de imagen. CONCLUSIÓN: En los Países Bajos existe una variación significativa entre hospitales y redes oncológicas respecto al uso de pruebas de imagen preoperatorias para el CRLM. El uso de MRI está aumentando, mientras que el uso de 18 F-FDG-PET-CT está disminuyendo.

Mechanisms and immunomodulatory properties of pre- and probiotics.

The human body is exposed to many xenobiotic, potentially harmful compounds. The intestinal immune system is crucial in protecting the human body from these substances. Moreover, many microorganisms, residing in the gastrointestinal tract, play an important role in modulating immune responses. Pre- and probiotics may have beneficial effects on the microbial composition and activity within the human gut, subsequently affecting the immune system. Prebiotics can exert their effects via different mechanisms, like selectively stimulating the growth of bacteria by providing substrates or via direct immune stimulation. Probiotics may have beneficial health effects via competition with pathogens for substrates and binding intestinal sites, bioconversions of for example sugars into fermentation products with inhibitory properties, production of growth substrates like vitamins for the host, direct antagonism of pathogens via antimicrobial peptide production, reduction of inflammation and stimulation of immune cells. This review focuses on the different mechanisms via which the pre- and probiotics exert their beneficial effects on the host, addressing their immunomodulatory properties in particular.

Exocrine pancreatic and enterocyte function in patients with advanced pancreatic cancer.

BACKGROUND & AIMS: Exocrine pancreatic function is affected in patients with locally advanced pancreatic cancer (LAPC), clinically leading to steatorrhea. It is unknown whether maldigestion and malabsorption can also be attributed to impaired intestinal enterocyte function. In this exploratory study enterocyte function was assessed in patients with locally advanced pancreatic cancer, treated with Irreversible Electroporation (IRE). METHODS: Enterocyte function was studied by Citrulline Generation Test (CGT). Intestinal absorption capacity of energy and fat was calculated from the differences between nutritional intake (four-days diary) and quantified fecal losses energy and fat in three-days feces collection. RESULTS: Twelve patients were included before IRE, and 5 patients had follow-up measurements. Fasted citrulline [CIT] and glutamine [GLU] levels were below reference levels of healthy subjects ([CIT] 38 ± 8 µmol/L; [GLU] 561 ± 77 µmol/L) both before ([CIT] 25 ± 9 µmol/L; [GLU] 65 ± 35 µmol/L) and after IRE ([CIT] 19 ± 9 µmol/L; [GLU] 53 ± 26 µmol/L) whereas CGT curves were normal, indicating normal enterocyte function (slope 0.21 ± 0.12 and 0.17 ± 0.07 µmol/L/min; [CIT] increment 63 ± 39 and 80 ± 44% respectively). Severe energy/fat malabsorption was present in 6 out of 12 patients with LAPC (mean loss 349 kcal/d, 13 g fat/d) before and in 4 out of 5 patients (mean loss 509 kcal/d, 32 g fat/d) after IRE respectively. CONCLUSIONS: Enterocyte function was generally within reference limits in patients with advanced pancreatic cancer. Severe malabsorption may be explained by exocrine pancreatic insufficiency.

Irreversible Electroporation in Hepatopancreaticobiliary Tumours.

Hepatopancreaticobiliary tumours are often diagnosed at an advanced disease stage, in which encasement or invasion of local biliary or vascular structures has already occurred. Irreversible electroporation (IRE) is an image-guided tumour ablation technique that induces cell death by exposing the tumour to high-voltage electrical pulses. The cellular membrane is disrupted, while sparing the extracellular matrix of critical tubular structures. The preservation of tissue integrity makes IRE an attractive treatment option for tumours in the vicinity of vital structures such as splanchnic blood vessels and major bile ducts. This article reviews current data and discusses future trends of IRE for hepatopancreaticobiliary tumours.

Assessment of Nutritional Status, Digestion and Absorption, and Quality of Life in Patients with Locally Advanced Pancreatic Cancer.

BACKGROUND AND AIM: To provide a comprehensive quantitative assessment of nutritional status, digestion and absorption, and quality of life (QoL) in patients with locally advanced pancreatic cancer (LAPC). METHODS: Sixteen patients with LAPC were prospectively assessed for weight loss (WL), body mass index (BMI), fat-free mass index (FFMI), handgrip strength (HGS), dietary macronutrient intake, serum vitamin levels, resting and total energy expenditure (REE and TEE, indirect calorimetry), intestinal absorption capacity and fecal losses (bomb calorimetry), exocrine pancreatic function (fecal elastase-1 (FE1)), and gastrointestinal quality of life (GIQLI). RESULTS: Two patients had a low BMI, 10 patients had WL > 10%/6 months, 8 patients had a FFMI < P10, and 8 patients had a HGS < P10. Measured REE was 33% higher (P = 0.002) than predicted REE. TEE was significantly higher than daily energy intake (P = 0.047). Malabsorption (<85%) of energy, fat, protein, and carbohydrates was observed in, respectively, 9, 8, 12, and 10 patients. FE1 levels were low (<200 µg/g) in 13 patients. Total QoL scored 71% (ample satisfactory). CONCLUSION: Patients with LAPC have a severely impaired nutritional status, most likely as a result of an increased REE and malabsorption due to exocrine pancreatic insufficiency. The trial is registered with PANFIRE clinicaltrials.gov NCT01939665.

Irreversible Electroporation to Treat Malignant Tumor Recurrences Within the Pelvic Cavity: A Case Series.

OBJECTIVE: To describe the initial experience with irreversible electroporation (IRE) to treat pelvic tumor recurrences. METHODS: A retrospective single-center analysis was performed. Adverse events were recorded using Common Terminology Criteria of Adverse Events (CTCAE) 4.0. Clinical outcome was determined using pain- and general- symptom assessment, including Seddon's peripheral nerve injury (PNI) types. Radiological outcome was evaluated by comparing baseline with three-month 18F-FDG PET-CT follow-up. RESULTS: Eight patients (nine tumors [recurrences of primary rectal (n = 4), anal (n = 1), sigmoid (n = 1), cervical (n = 1), and renal cell carcinoma (n = 1)]) underwent percutaneous IRE as salvage therapy. Median longest tumor diameter was 3.7 cm (range 1.2-7.0). One CTCAE grade III adverse event (hemorrhage) and eight CTCAE grade II complications occurred in 6/8 patients: vagino-tumoral fistula (n = 1), lower limb motor loss (n = 3; PNI type II) with partial recovery in one patient, hypotonic bladder (n = 2; PNI types I and II) with complete recovery in one patient, and upper limb motor loss (n = 2; PNI type II) with partial recovery in both patients. No residual tumor tissue was observed at 3-month follow-up. After a median follow-up of 12 months, local progression was observed in 5/9 lesions (4/5 were >3 cm pre-IRE); one lesion was successfully retreated. Debilitating preprocedural pain (n = 3) remained unchanged (n = 1) or improved (n = 2). CONCLUSION: IRE may represent a suitable technique to treat pelvic tumor recurrences, although permanent neural function loss can occur. Complete ablation seems realistic for smaller lesions; for larger lesions symptom control should be the focus.

Correction: Time-Dependent Impact of Irreversible Electroporation on Pancreas, Liver, Blood Vessels and Nerves: A Systematic Review of Experimental Studies.

[This corrects the article DOI: 10.1371/journal.pone.0166987.].

Time-Dependent Impact of Irreversible Electroporation on Pancreas, Liver, Blood Vessels and Nerves: A Systematic Review of Experimental Studies.

INTRODUCTION: Irreversible electroporation (IRE) is a novel ablation technique in the treatment of unresectable cancer. The non-thermal mechanism is thought to cause mostly apoptosis compared to necrosis in thermal techniques. Both in experimental and clinical studies, a waiting time between ablation and tissue or imaging analysis to allow for cell death through apoptosis, is often reported. However, the dynamics of the IRE effect over time remain unknown. Therefore, this study aims to summarize these effects in relation to the time between treatment and evaluation. METHODS: A systematic search was performed in Pubmed, Embase and the Cochrane Library for original articles using IRE on pancreas, liver or surrounding structures in animal or human studies. Data on pathology and time between IRE and evaluation were extracted. RESULTS: Of 2602 screened studies, 36 could be included, regarding IRE in liver (n = 24), pancreas (n = 4), blood vessels (n = 4) and nerves (n = 4) in over 440 animals (pig, rat, goat and rabbit). No eligible human studies were found. In liver and pancreas, the first signs of apoptosis and haemorrhage were observed 1-2 hours after treatment, and remained visible until 24 hours in liver and 7 days in pancreas after which the damaged tissue was replaced by fibrosis. In solitary blood vessels, the tunica media, intima and lumen remained unchanged for 24 hours. After 7 days, inflammation, fibrosis and loss of smooth muscle cells were demonstrated, which persisted until 35 days. In nerves, the median time until demonstrable histological changes was 7 days. CONCLUSIONS: Tissue damage after IRE is a dynamic process with remarkable time differences between tissues in animals. Whereas pancreas and liver showed the first damages after 1-2 hours, this took 24 hours in blood vessels and 7 days in nerves.

Anaesthetic management during open and percutaneous irreversible electroporation.

BACKGROUND: Irreversible electroporation (IRE) is a novel tumour ablation technique involving repetitive application of electrical energy around a tumour. The use of pulsed electrical gradients carries a risk of cardiac arrhythmias, severe muscle contractions, and seizures. We aimed to identify IRE-related risks and the appropriate precautions for anaesthetic management. METHODS: All patients who were treated with IRE were prospectively included. Exclusion criteria were arrhythmias, congestive heart failure, active coronary artery disease, and epilepsy. All procedures were performed under general anaesthesia with complete muscle relaxation during ECG-synchronized pulsing. Adverse events, cardiovascular effects, blood samples, cerebral activity, and post-procedural pain were analysed. RESULTS: Twenty-eight patients underwent 30 IRE sessions for tumours in the liver, pancreas, kidney, and lesser pelvis. No major adverse events occurred during IRE. Median systolic and diastolic blood pressure increased by 44 mm Hg (range -7 to 108 mm Hg) and 19 mm Hg (range 1-50 mm Hg), respectively. Two transient minor cardiac arrhythmias without haemodynamic consequences were observed. Muscle contractions were mild and IRE caused no reactive brain activity on a simplified EEG. Pain in the first 24 h after percutaneous IRE was generally mild, but higher pain scores were reported after pancreatic treatment (mean VAS score 3; range 0-9). CONCLUSIONS: Side-effects during IRE on tumours in the liver, pancreas, kidney, and lesser pelvis seem mild and manageable when current recommendations for anaesthesia management, including deep muscle relaxation and ECG synchronized pulsing, are followed. Electrical pulses do not seem to cause reactive cerebral activity and evidence for pre-existing atrial fibrillation as an absolute contra-indication for IRE is questionable.

Low-dose thrombolysis for thromboembolic lower extremity arterial occlusions is effective without major hemorrhagic complications.

OBJECTIVE: To evaluate the efficacy and bleeding complications associated with a low-dose thrombolysis protocol for thromboembolic lower extremity arterial occlusions. DESIGN: A retrospective cohort study. MATERIALS AND METHODS: A retrospective analysis was performed using data from all consecutive patients who underwent catheter-directed, intra-arterial thrombolysis for thromboembolic lower extremity arterial occlusions between January 2004 and May 2013. All patients were treated on a standard surgical ward. Endpoints were incidence of bleeding complications, duration of thrombolysis, angiographic patency rate, 30-day mortality rate, and amputation-free rate at 6 months. RESULTS: Of the 171 cases analyzed, 129 cases underwent low-dose thrombolysis and 42 underwent high-dose thrombolysis. No major bleeding complications occurred in the low-dose group versus 5% in the high-dose group (p = .01). The median duration of thrombolysis was 67 hours (4-304 hours) in the low-dose and 49 hours (2-171 hours) in the high-dose group (p = .027). Angiographic patency was restored in 67% of the cases in the low-dose group versus 79% of the high-dose group (p = .17). The 30-day mortality rates were 1% in the low-dose versus 5% in the high-dose group (p = .09). However, this higher mortality rate was not related to bleeding complications. Major amputation-free rates at 6 months were 81% in the low-dose group and 88% in the high-dose group (p = .22). CONCLUSIONS: Based on this data series, low-dose thrombolysis for thromboembolic lower extremity arterial occlusions is as effective as high-dose thrombolysis; however, the risk of major bleeding complications is substantially lower when using low-dose thrombolysis.

Ablation of colorectal liver metastases by irreversible electroporation: results of the COLDFIRE-I ablate-and-resect study.

OBJECTIVES: Irreversible electroporation (IRE) is a new ablation technique that relies on high-voltage electrical pulses. This clinical study evaluates the pathological response of colorectal liver metastases (CRLM) treated with IRE and the clinical safety and feasibility. METHODS: Ten patients with resectable CRLM were included. During laparotomy, the metastases were treated with IRE and resected 60 min later. Safety and feasibility were assessed based on adverse events, laboratory values, technical success and intra-operative ultrasound findings. Tissue response was assessed using triphenyl tetrazolium chloride (TTC) vitality staining and (immuno)histochemical stainings (HE, complement-3d and caspase-3). RESULTS: Ten lesions with a mean diameter of 2.4 cm were successfully electroporated and resected, on average, 84 min later (range 51-153 min). One minor transient cardiac arrhythmia occurred during IRE. Ultrasound showed a sharply demarcated hypoechoic ablation zone around the tumour. TTC showed avitality of all lesions, covering the complete tumour in 8/10 lesions. Although immunohistochemistry proved heterogeneous and difficult to interpret within the tumours, it confirmed irreversible cell damage in the tumour-free margin of all specimens. CONCLUSIONS: This ablate-and-resect study demonstrated avitality caused by IRE of CRLM in humans. Further characterisation of tissue- and tumour-specific electrical properties is warranted to improve ablation protocols for maximised tissue ablation. KEY POINTS: • Irreversible electroporation induces cell death in colorectal liver metastases within 1 h. • The ablation zone shows a sharp demarcation between avital and vital tissue. • Apoptosis is involved in cell death of colorectal liver metastases after IRE. • Effects of IRE can be monitored real-time using intraoperative ultrasound. • Local electrical heterogeneities of tumour tissue may require tumour-specific ablation protocols.