Mathematics optimises cancer treatment

Radiation therapy is one of the most common forms of treatment for cancer. In IMRT the flow profiles of the rays are modulated through an optimisation of the parameters of the X-Ray accelerators. For traditional radiation treatment only homogenous flow profiles are used. The use of IMRT is increasing and facilities can currently be found at most major hospitals in Sweden.

“The more difficult the location of the cancer tumour, the great benefit IMRT provides,” says Fredrik Carlsson who is an industrial doctoral student at KTH from the medical technology company RaySearch Laboratories AB. On Friday 25 April he will publicly defend his thesis entitled "Utilizing Problem Structure in Optimization of Radiation Therapy" at KTH.

“IMRT is primarily used when the tumours are located close to healthy, vital organs and extremely precise radiation treatment is essential, for example in the cases of prostate cancer and cancer in the head and throat areas. I have developed methods and evaluated how optimisation problems can be more efficiently solved with the aim of improving the quality of the radiation treatment,” says Fredrik Carlsson.

Thousand of parameters are applied in the planning of the radiation dose. By rapidly optimising the doses efficiently delivered to the patient, treatment periods can be cut and hospital resources utilised more efficiently.

In his research Fredrik Carlsson has used optimisation (mathematical programming) – a mathematical science used to solve problems within many fields such as finance, telecommunications and transport. In this case the issue was a problem in radiation treatment. In order to provide the best treatment for cancer patients, it is essential to give a high dose to the tumour cells and a low dose to the healthy tissue that surrounds the tumour.

This industrial doctoral project has been financed by the Swedish Research Council and RaySearch Laboratories and has been implemented in a cooperative venture between the latter and the Division of Optimization and Systems Theory at KTH. RaySearch is a spin-off company from Karolinska Institutet and has developed advanced software products which calculate and optimise radiation doses for IMRT. Henrik Rehbinder, the Research Director of the company is extremely satisfied with both the cooperation with KTH and with these research results.

“We have gained more in-depth knowledge and optimisation methods that we can utilise in our products. These results have also laid the foundation for the potential products of the future,” he stated.

Fredrik Carlsson began by testing these methods on a small scale at KTH and then later in RaySearch software with real patient data and algorithms of the type used at the radiation clinics.

“This is how I have been able to test these methods on realistic cases. Hopefully these methods will be implemented in RaySearch products and applied clinically,” he says.

For more information, please contact:

Fredrik Carlsson, RaySearch Laboratories AB
+ 46 (0)8 54506130, fredrik.carlsson@raysearchlabs.com
Anders Forsgren, Professor, Division of Optimization and Systems Theory, KTH
+ 46 (0)8 790 71 27, andersf@kth.se

Susanne Rosén