A simplified laser treatment planning system: proof of concept

The physician using a laser in medicine should have treatment planning software available that will help him or her to better understand the full effects of the laser radiation on the patient, similar to that of a radiation oncologist. Combining this software with imaging scans from the patient, treatments can be optimized for individual patients.

Using off-the-shelf computers and software, we put together a simple system that is able to calculate thermal profiles from laser irradiation using an algorithm that runs in real time on a laptop computer with commercial software. The tissues used in these studies are simulated. We use realistic parameters and add some random blood vessels to the simulated tissue.

We demonstrate in the simulations the temperature profile in tissue after laser irradiation. We can see build up of temperature in tissue irradiated with multiple pulses at 2 Hz repetition rate. The simulations show how the volume of the tissue is important in calculating thermal relaxation times. We also show how temperature relaxes away from small volumes in a short time and longer durations are needed for larger volumes of tissue.

The importance of understanding how a laser interacts fully with the tissue will allow the surgeon to better determine when a laser is appropriate and which laser is optimal for a patient. The results show how these calculations can be made in a simplified fashion. Ultimately, it would be convenient to combine such software with imaging systems for careful laser treatment planning.