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A research team from Chalmers University of Technology, Gothenburg, Sweden, has developed two new techniques of cancer diagnosis and treatment with the aid of microwaves. One method is an alternative to mammography that uses X-rays to detect breast cancer. The other method aims to treat tumours in the head and neck by heating the cancer cells.
Andreas Fhager, Associate Professor of Biomedical Electromagnetics at Chalmers, has developed a system to detect breast cancer with a new technique known as microwave tomography. Fhager's "microwave tomograph" currently consists of some 30 antennas arranged around a cylindrical container adapted to the breast. All antennas act both as transmitters and receivers. The microwaves spread out in a complex pattern that is analysed by advanced algorithms, which reconstruct an image of the breast tissue in 3D.
"We obtain three-dimensional images showing significantly better contrast between healthy and malignant tissue compared to X-rays," Fhager explained. "That makes it easier to detect even really small tumours that may currently be obscured by healthy tissue, thus creating the preconditions for much more reliable diagnosis. Unlike X-rays, the technique also emits negligible doses of non-ionising radiation – less than a hundredth of the radiation to which you are exposed when talking on a mobile phone."
In the second Chalmers project, the microwaves are used to destroy the tumours by heating them, a process known as hyperthermia. Antennas transmit microwaves with high efficiency, perfectly synchronised to heat up individual tumours. Clinical studies have shown that treatment with conventional radiotherapy and chemotherapy in combination with hyperthermia may double the long-term ability to cure certain forms of cancer, such as cervical cancer and soft-tissue sarcoma.
"We are now developing a new hyperthermia system that can reach deep-seated tumours in the head and neck with high accuracy," said Hana Dobšíček Trefná, who holds a doctorate in biomedical engineering. "In this way, higher temperatures can be reached in the tumour without affecting the surrounding tissue."
With time, the Chalmers team hopes to be able to combine both methods. As soon as a tumour is detected, the already connected antennas could be used to start treating the tumour directly while at the same time monitoring that the right tissue is heated up. The method should also be applicable for parts of the body other than breasts, head and neck. Theranostics – the treatment and diagnosis of diseases in a single system – is a growing area of research, and the Chalmers team believes that microwaves have great potential in the field.
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