Microwave hyperthermia for cancer treatment

This is a project on the development of systems for hyperthermia treatment of deep-seated cancerous tumors, based on the microwave technique. The Chalmers research team is from the Biomedical electromagnetics research group. Their work in this field aims at clinical introduction of hyperthermia in Sweden, developing an UWB hyperthermia system for treatment of head and neck tumors, and exploring the possibility of hyperthermia treatment of brain tumors in children.

The group concentrates especially on tumors in the neck area, and brain tumors in children.
Hyperthermia means repeated heating of the tumor to just over 40°C. This treatment is toxic for the tumor itself, whilst also making the tumor more sensitive to traditional chemo and radiation therapies. This in turn leads to the possibility of reducing treatment side effects by reducing radiation doses and cytostatic drugs with unchanged treatment results. Clinical studies have also shown doubled cure rates when combining hyperthermia with traditional cancer treatment.

The microwave technique also enables heat treatment of tumors which are deep-seated and/or relatively hard to access in the body. The microwaves are transmitted from a number of antennas enclosing the relevant body part. The heat effect is developed in the tumor by the transmission of microwaves which are adjusted in time, frequency and strength in order to work together to form a focus in the desired location. This places high demands on the precision of the system, in order for the heating to be concentrated on the tumor, without heating surrounding healthy tissue.

It presents a great challenge to calculate exactly how each antenna should transmit signals to reach the desired focus on the right spot. The research group is therefore developing algorithms based on the so called “time reversal” technique. The heavy mathematical computations must for instance take into account the shape of the body tissue and the electric material qualities of the relevant body part. This requires a computer model which is completely unique for each patient and each time of treatment.