I’m going to talk about interventional oncology which is the new discipline in the field of cancer care. It aspires to join surgery, radiation oncology and medical oncology as the fourth pillar in the treatment of cancer. Interventional oncology uses minimally invasive image guided methods to deal with cancer and we mainly focus on the local destruction of tumours. It works well and it has the advantage that you don’t need to open the patient up, you can actually destroy the tumour and then leave it there to be absorbed by the body. That has obvious advantages, including quicker recovery of the patient, fewer complications and the oncological results are excellent.
How do you destroy it?
Using a variety of forms of energy, for example radiofrequency waves work in a very similar way to microwaves. What you do is you give local anaesthetic and sedation and introduce an electrode into the tumour that’s going to be destroyed, for example in the liver or the kidney. You confirm the position using CT scanning and show that the electrode is in the correct position inside the tumour and once you’re satisfied that you are where you need to be you then pass electricity through the electrode and that allows radiofrequency waves to emerge from the electrode and cook the tumour, so that’s what it is. It actually is cooking of the tumour and destruction of it without the need to take it out.
How do you ensure that you don’t damage the wrong area?
By making sure that your electrode is in exactly the right place. You have to be millimetre accurate and you have to confirm the position of the electrode by checking using CT images that you’re not too close to something that needs to avoid being heated too much in order not to damage it.
Are there other methods that you can use?
You can use cryotherapy, which is freezing the tumour, and in certain circumstances that is better and there are other different forms of energy that are coming on-stream now, newer ones, for example irreversible electroporation, so-called. That’s a non-thermal form of destruction; instead of heating the tumour you punch holes in the cell membrane and that stops the cell from being able to regulate itself, it destroys homeostasis, and the cell dies because it can no longer regulate its functions. That’s very useful in sensitive areas where you’re close to vital organs because you’re not using heat and therefore you can be particularly accurate. But everything has advantages and disadvantages and you choose the method that’s most suitable for a particular patient.
Are you using all new techniques?
No, some aspects of it are new like irreversible electroporation and that is really, for practical purposes, experimental. But other methods such as radiofrequency ablation and microwave ablation have been around for quite a while. For small tumours they’re tried and tested and have been shown to work very well and they’re cheaper than surgical alternatives. So, for example, when you’re destroying small tumours in the kidney the three main methods of treatment are either to take the kidney out, nephrectomy, total nephrectomy, partial nephrectomy – take part of the kidney out, or using a form of ablation. It has actually been shown in studies that ablation is a very cost effective way of dealing with these tumours.
Interventional oncology should be considered a discipline that works side by side with the other disciplines that I mentioned, medical oncology, radiotherapy and surgical oncology. Particularly it’s very close to radiation oncology, to radiotherapy. They’re both dealing with the local treatment of tumours, they both use imaging guidance and there’s an overlap between them, they are sister disciplines. Collaboration between them, clinical collaboration and academic collaboration, could be very, very beneficial. Also it has been shown to work very well in synergy with certain forms of drug administration so, for example, if you’re destroying a tumour with radiofrequency, if you inject that particular patient with a chemotherapeutic agent such as doxorubicin you may achieve a larger area of destruction. So there’s a lot of potential there for collaboration between these disciplines and they shouldn’t be seen as competitive, they should be seen as collaborative more than anything else.