Showing papers by "Hana Dobsicek Trefna published in 2018"
01 Mar 2018
TL;DR: Although the analysis results in terms of power loss density show that all the applicators are capable of heating sufficiently large deep-seated spherical tumors in the authors' simple head model, more antennas resulted in higher power absorption in the tumors and higher values of tumor coverage.
Abstract: Addition of hyperthermia to modern cancer therapies is highly effective in improving the treatment outcome of deep-seated head and neck tumors. Brain tumors, on the other hand, are more difficult for heating due to high perfusion and thermal conduction. However, late side effects of conventional therapies in children with brain cancer make it important to combine hyperthermia with these therapies. For this purpose, a hyperthermia applicator capable of efficient heat delivery to large and deep-seated brain tumors is required. In this paper, we evaluate preliminary design of hyperthermia applicators for treatment of deep-seated brain tumors in children. We present three applicators with a different numbers of antennas. The performance of the applicators is compared and evaluated in terms of hyperthermia quality indicators. Although the analysis results in terms of power loss density show that all the applicators are capable of heating sufficiently large deep-seated spherical tumors in our simple head model, more antennas resulted in higher power absorption in the tumors and higher values of tumor coverage.
27 citations
TL;DR: Adequate coverage of the skin temperature distribution during superficial hyperthermia treatment requires the use of >50 stationary sensors per 400 cm2 applicator, and thermal mapping is a valid alternative.
Abstract: Purpose: Tumor response and treatment toxicity are related to minimum and maximum tissue temperatures during hyperthermia, respectively. Using a large set of clinical data, we analyzed the ...
17 citations
01 Jan 2018
TL;DR: This paper proposes and analyzes a pair of self-calibration algorithms which rely only on S-matrix measurements of the N-port array applicator device, avoiding the need for external references and making real-time in-treatment calibration possible.
Abstract: In deep microwave hyperthermia (MW-HT), antenna arrays are used to generate an interference pattern which focuses energy in the tumor location. These arrays are subject to a number of disturbances which must be compensated for through calibration. This paper proposes and analyzes a pair of self-calibration algorithms, i.e. calibration procedures which rely only on S-matrix measurements of the N-port array applicator device, avoiding the need for external references and making real-time in-treatment calibration possible. Two algorithms are analyzed by means of simulations and experiments in terms of reliability and sensitivity to different kinds of disturbances. The results show that one of two implemented algorithms can converge to the same calibration values obtained when using an external calibration reference (monopole antenna).
2 citations