Building a cancer treatment training system: the problem

Liver cancer is pretty bad. About 70% of people who are diagnosed, die as a result of the cancer. Even worse, mechanically removing the tumor usually also means removal of a significant portion of healthy tissue, which is bad in itself, but sometimes also impossible, for example due to the tumor’s position in the liver or weak liver function in the patient.

One solution is of course a liver transplant, but unfortunately getting transplantable livers is hard, and growing them in a lab is still a long way away. A third option is called an ablation treatment, where portion of the liver tissue is destroyed by freezing or heating it. This happens by inserting a large needle to the liver, often from the lateral side between the ribs. The heating needles work by inducing an AC current or by microwave radiation.

At this point you may be wondering, wasn’t I reading a software company blog? Just… Bear with me for a second here.

The problem with ablation treatments is, that their effectiveness varies highly depending on the experience of the radiologist performing the operation. The needle effectively burns a volume inside the liver, and if it doesn’t hit the correct spot, we end up destroying healthy liver tissue and leaving the tumour intact.

Another issue is, that there is currently very little in ways of training for the procedure. Ablation treatment is physically quite similar to biopsies. The patient is placed in some kind of imaging machine, commonly CT or ultrasound, and the needle is inserted into the tumor. In Finland, only radiologists with years of experience in biopsies and other operations perform ablations, but what if we could help doctors train these procedures? Could we increase their availability and effectiveness?

This was the problem presented to us by researcher Mika Pollari from Aalto University and what we set to find out over 4 months. A short series of blog posts will describe how we set out to find if building a training system like this could be built, and what we ended up constructing.

Specifically, we decided we would build a simulator which:

1. Would have a human analogue, to simulate needle insertion
2. Would have a needle suitable for ablation and a system which tracks the needle’s location
3. Would display a simulation of the guidance images (CT or MRI)

The combination should allow the doctor to practice the most important steps of the procedure. We did not consider the problem of heat sinks (blood vessels), or liver movements or other structural issues. The project then, will include a physical hardware component (the mannequin or ‘phantom’), an electronic component (the tracker) and a software component for displaying the simulation (the guidance system).

In the next post of this series it is described how we actually set out to solve the problem. Until the next time!