Many patients with hepatocellular carcinoma (HCR) have poor prognosis, as the disease is often detected at the final stage. For patients with tumours which have been inoperable until this time, irreversible electroporation (NanoKnife) is a new chance. The largest research ever conducted into the NanoKnife started in 2011 at the Institute for X-Ray Diagnostics of the University Hospital Regensburg. The study has confirmed the benefits in terms of the chances of survival and recurrence.
Within the framework of the research, 71 patients of the clinic who had undergone NanoKnife treatment were observed retrospectively for five years. “Due to the large number of patients and long-term follow-up, our study is the largest of all the research into the NanoKnife until this time. Even if we consider only the results obtained by our institute, it is important information telling us about the effectiveness of the technique, which may contribute to its use in a larger number of patients in future,” explains Professor Christian Stroschensky, Head of the Institute for X-Ray Diagnostics.
After treatment, the patients lived on average for more than two years. During the six-week follow-up complete removal of the tumour was found in approximately 93% of cancer patients. Only a third of the patients who had undergone the treatment developed recurrence. “No other treatment options were used to treat the patients except the NanoKnife. Taking this into account, the results can be assessed as highly positive,” says privat-docent Professor Dr. Philipp Wiggermann, one of the authors of the study, in a report. There are various ways to treat HCR. The best method is surgery. However, a tumour can be surgically removed only if a small portion of the liver tissue is affected. Alternative surgery is radiofrequency ablation (RFA). In this case, the tumour is destroyed by using high temperatures. For this purpose, a special probe is put right into the tumour. But this method has its limitations. For example, only tumours smaller than five centimetres in size can be treated. Often not all cancer cells are removed. If all traditional methods are exhausted, the NanoKnife offers the sick a new chance for a cure.
Irreversible electroporation, like RFA, is a minimally invasive method. Cancer metastases in the liver are destroyed by targeting them with electrical pulses. To do this, several probe electrodes are placed in the centre of the liver tumour through the skin. The doctor controls their placement by using imaging diagnostic methods, such as sonography or computed tomography. When the electrodes are mounted, short electric pulses with 3000 volts are sent to them. The magnetic field arising from this leads to rupture of the cancer cell membrane, which in turn leads to controlled cell death. The procedure can last up to two and a half hours.
Since the intervention is minimally invasive, the patient can be discharged in 3-4 days. Another advantage is that not all cancer cells need to be destroyed during this treatment, the procedure can be repeated in 6-8 weeks.
“The NanoKnife can be used for liver tumours up to six centimetres in size. Patients benefit from the positive additional effects of this gentle treatment. In contrast to surgery, after the minimally invasive intervention, only tiny scars remain,” says Wiggermann in the institute report.