Irreversible electroporation (IRE) is a non-thermal ablative process in which short but strong electric fields are generated using precisely placed needles and computer-controlled potential differences between these needles. Ablation of the cells with IRE causes apoptotic cell death. Due to the mostly non-thermal effect, IRE is expected to cause less damage to adjacent structures than other thermal ablation approaches (radiofrequency ablation [RFA], microwave ablation [MWA], and cryoablation). In this way, pancreatic and liver tumours located near large blood vessels or other sensitive structures, such as nerves and bile ducts, can be removed without damaging them. IRE can be used percutaneously, laparoscopically or in open surgery.

The target group for IRE in pancreatic cancer includes patients with inoperable, locally advanced pancreatic tumours and liver cancer patients with inoperable primary or secondary liver cancer who have a contraindication to thermoablation.

The systematic literature review identified 15 observational studies meeting the selection criteria, eight for pancreatic cancer and seven for liver cancer. No RCTs were found. One of the studies conducted for pancreatic cancer was a (two-armed) non-RCT involving 21 patients receiving the IRE intervention with a median follow-up of eight months. The remaining seven prospective single-arm observational studies included 226 patients treated with IRE. Six of them had a median follow-up of ≤12 months. The longest follow-up period was 28 months. For liver cancer, seven prospective single-arm studies with 151 patients were identified: 220 lesions treated with IRE were treated. The average follow-up time was ≤18 months in five of these studies and the maximum was 24 months. In liver cancer, one study was not included because no safety results were reported.

In general, the quality of evidence for both indications is very low. The single-arm studies conducted to determine efficacy and safety results are severely limited due to their small size, short follow-up time, and highly selected populations who had received different types of treatments. Data enabling the calculation of overall survival (OS), progression-free survival (PFS) and other critical outcomes such as quality of life (QoL) were also lacking in many of the studies. This is a major obstacle to drawing conclusions about the potential of IRE to treat these tumours. This was particularly the case with liver cancer, where most studies reported only local recurrence during follow-up. Other important deficiencies include the lack of standardised definitions of success, the unclear classification of IRE-related complications and the different and possible underreporting of some types of AE.

Therefore, there is insufficient evidence that IRE is more effective/safe or at least as effective/safe as the conventional standard of care (chemotherapy, chemoradiotherapy or palliative care) in the treatment of inoperable locally advanced pancreatic cancer (LAPC) or that IRE is more effective/safe or at least as effective/safe as the conventional standard of care (transarterial chemoembolisation [TACE], sorafenib or palliative care) in the treatment of primary or secondary inoperable liver cancer that is not suitable for thermal ablation.