UZ Leuven laser burns away 'wrong' brain tissue with MRI as gps

18/02/2020

From now on, for epilepsy patients who cannot be helped with drugs, a new minimally invasive surgery is possible, in which a laser scorches the tissue that provokes epilepsy in an MRI device. Because the tissue is burned during an MRI scan, the brain surgeon can monitor during the operation whether the lesion is made in the right place and what the exact temperature is in the tissue around it. UZ Leuven applied the MRI-guided laser ablation to a young woman for the first time in the Benelux.

In one in three people with epilepsy, drugs have little effect. If they also regularly have epileptic seizures, they may qualify for epilepsy surgery. People with a lot of epileptic seizures have a very hard time living a normal social life. If drugs do not get a grip on the condition, a neurologist may decide to have brain surgery after an extensive pre-surgical evaluation. Tissue burning via electrodes has been around for a long time, but the scorching of the brain tissue that causes the epilepsy is less controlled. A new alternative is an extremely fine laser in combination with a precise MRI as GPS.

The brain surgeon drills a miniscule hole in the skull and then slides a small tube through the meninges with a laser into the brain at the end. A CT scan in the operating theater checks whether the tube is in exactly the right place. The patient is then taken from the operating theatre to the MRI scanner, where the surgeon can use intelligent software to calculate precisely where he wants to burn away tissue and at what temperature. The tube is then moved step by step along the abnormal brain tissue. In this way, the laser can do its work extremely accurately and burn away the brain tissue that causes the epilepsy. The surgeon sees the results on the screen in real time.


Burning away with laser precision

Burning brain tissue carries risks. By doing the procedure in the MRI scanner, which can measure temperature changes, the surgeon can see at any time what the temperature is in the tissue he wants to burn away and in the brain tissue around it. Certain nerve pathways around the 'bad' brain tissue can be crucial for vision, reading, motor skills or speech. It is therefore very important to burn away the faulty brain tissue in a controlled way.

The tube that goes into the brain also contains a cavity through which water flows to cool down the laser and to regulate the temperature very precisely. The laser treatment takes less time compared to a classic operation to remove brain tissue and the operation itself is much less stressful for the patient. His recovery is therefore faster than in a traditional brain surgery.

Great added value

Because epilepsy is difficult to evaluate in the short term, the doctors do not yet make any statements about the long-term results of the procedure. The fact is, however, that the patient who was operated on at UZ Leuven before the operation had several major epileptic seizures per day and until now, one month after the operation, only had a few smaller non-obstructive seizures.

Prof. Dr. Tom Theys, neurosurgeon at UZ Leuven: "Such a laser treatment is a delicate brain operation, but the operation was technically perfect. The abnormal brain tissue was burned away without damaging the normal brain tissue. The fact that we can scorch the brain tissue in real time, in a controlled way, is an important added value. Together with all the epilepsy centers, it would be good to see how we can offer this rather expensive technique in Belgium to a limited number of patients who really need it".

The new method already existed in the USA and is now being introduced in Europe for a select group of patients with epilepsy. The technique has also been used successfully worldwide for deep brain tumors. In Belgium, the Riziv does not yet reimburse the cost of surgery, so UZ Leuven and the special solidarity fund contributed to the costs for this first patient. The intervention is a collaboration between the departments of neurology, anaesthesiology, radiology and neurosurgery.


Source: UZ Leuven