Lung cancer is one of the most common cancers in the UK. The symptoms often do not appear until the disease is at an advanced stage, and the prognosis is generally poor. The lung is also a common site for metastases from other primary cancers, such as breast and colon cancer.
The choice of treatment for primary lung cancer and metastases in the lung is influenced primarily by the type of tumour and stage of the disease. Treatments include surgical resection (open or thoracoscopic), chemotherapy, radiotherapy, photodynamic therapy or thermal ablation, or a combination of these. If the tumour protrudes into the major airways, interventional bronchoscopic treatments including diathermy, laser therapy, cryotherapy, brachytherapy or photodynamic therapy may be used. Irreversible electroporation is a non-thermal cell-destruction technique, which is claimed to allow targeted destruction of cancerous cells with less damage to supporting connective tissue (such as nearby blood vessels and nerves) than with other types of treatment.
The aim of irreversible electroporation is to destroy cancerous cells by subjecting them to a series of short electrical pulses using high-voltage direct current. This creates multiple holes in the cell membrane, irreversibly damaging the cell's homeostasis mechanisms and leading to cell death.
The procedure is performed with the patient under general anaesthesia. A neuromuscular blocking agent is essential to prevent uncontrolled severe muscle contractions caused by the electric current. Bipolar or unipolar electrode needles are introduced percutaneously (or by open surgical or laparoscopic approaches) and guided into place in and adjacent to the target tumour using imaging guidance. A series of very short electrical pulses is delivered over several minutes to ablate the tumour. The electrodes may then be repositioned to extend the zone of electroporation until the entire tumour and an appropriate margin have been ablated. Cardiac synchronisation is used to time delivery of the electrical pulse within the refractory period of the heart cycle, minimising the risk of arrhythmia.