Novel Treatments lacking Evidence
Despite the name, “Nanoknife” is not a surgical treatment.
The purpose is to destroy tumour cells within inoperable tumours using a process called electroporation, or electropermeabilization. Short pulses of high-voltage electrical energy are passed between electrodes placed adjacent to the tumour, and this results in the cell membranes becoming more porous. In this way cells are killed without the use of thermal energy, as would be the case in radiofrequency ablation or microwave ablation.
Whilst this represents an interesting technology, there are currently no trials confirming any benefit over existing technologies, and it is currently not available within the NHS in the UK. The company behind the technology (Angiodynamics) should be encouraged to invest in well-designed trials to properly assess the technique and, until these are available, we would not encourage patients to seek out this form of treatment in the private sector.
NanoKnife currently costs £13,500 privately (Sept. 2014).
All radiotherapy is targeted towards the tumour, but by using complex computer models the focus of this targeting can be improved (“stereotactic radiotherapy”). This approach allows a higher dose to be administered in a shorter time with the same side-effects. “Cyberknife” is an example of this form of therapy. While there are potential advantages from shorter treatment courses and perhaps fewer side-effects, there is no evidence as yet that it is more effective than standard treatments.
Microwave Ablation and High Intensity Focused Ultrasound (HIFU) are other methods of causing tumour cell destruction by tissue heating beyond a point where it can survive. The cell destruction is not however tumour specific and excessive tissue destruction can result in complications. To minimise this most thermal treatments are focused on the centre of the tumour and will usually leave a viable rim near the surface.
There is no current evidence that any of the local thermal tumour ablation techniques has any advantage over standard treatment and as such the recommendation is that they are undertaken within clinical trials.