A fast algorithm to find optimal controls of multiantenna applicatorsin regional hyperthermia

Abstract

The goal of regional hyperthermia is to heat up deeply located tumours totemperatures above 42 °C while keeping the temperatures in normaltissues below tissue-dependent critical values. The aim of this paper is todescribe and analyse functions which can be used for computing hyperthermiatreatment plans in line with these criteria. All the functionals considered herecan be optimized by efficient numerical methods. We started with the workinghypothesis that maximizing the quotient of integral absorbed power inside thetumour and a weighted energy norm outside the tumour leads to clinicallyuseful power distributions which also yield favourable temperaturedistributions. The presented methods have been implemented and tested withreal patient data from the Charité Berlin, Campus Virchow-Klinikum. Theresults obtained by these fast routines are comparable with those obtained byrelatively expensive global optimization techniques. Thus the describedmethods are very promising for online optimization in a hybrid system forregional hyperthermia where a fast response to MR-based information isimportant.