To improve the reliability and further increase applicability of treatment planning, ongoing developments focus on 1) dielectric imaging to derive patient-specific dielectric properties, 2) advanced thermal modelling including discrete vasculature and 3) biological modelling to predict the radiosensitizing effect of hyperthermia in terms of equivalent radiation dose. Presently, main clinical applications of hyperthermia treatment planning are 1) applicator selection, 2) heating ability evaluation and 3) on-line treatment guidance. Thanks to developments over the past decade, treatment planning becomes increasingly important in the clinical workflow. Hyperthermia treatment planning was mainly a research tool for decades, because of high computational costs and limited quantitative accuracy of treatment planning predictions due to a lack of patient-specific tissue properties. Hyperthermia treatment quality depends on tumour temperatures achieved and treatment planning (i.e., simulation and optimization of absorbed power and temperature distributions) could be very useful to ensure and improve treatment quality. The proposed model could be extended to different body regions and used to develop an application-oriented design of antennas for hyperthermia treatment.ĭuring hyperthermia, tumour tissue is heated to 40-43 ☌ using radiofrequency or microwave antennas, which strongly enhances effectiveness of radiotherapy and chemotherapy. To further enhance the effectiveness of the treatment, the use of a time-modulated power is studied.
TAJIMA PULSE DATABASE PROBLEMS PATCH
The new version of the patch can withstand a temperature of 42.5 ☌ for 60 min of treatment. The treatment performed using the old version of the antenna lead to unsuccessful results (40 ☌ after 60 min), whilst the novel robust design could successfully treat the target region. Indeed, the antenna bandwidth is increased with about 7%. A more robust and effective design is obtained, with respect to its previous version. The effectiveness of the antenna is evaluated simulating the treatment with a recent non-linear multi-physic model, considering the different description of tumor vasculature. The geometrical parameters of the antennas are selected to provide a robust design against the variation of the phantom parameters. Instead of using patient-specific geometries with discrete vascular tree models, a surface phantom with a continuum 3D blood perfusion model of tumors is used. The proposed general approach is used to investigate the specific case of the hyperthermia treatment of abdominal rhabdomyosarcoma. The proposed tissue-mimicking mixtures along with 3D-printed structures can be used as a valuable test platform for microwave bone imaging system development.Īn existing compact patch antenna working at 434 MHz is re-designed using the proposed methodology. For solid tissue-mimicking mixtures, this difference was found to be 3.93% and 0.64% for skin, 6.13% and 9.21% for cortical bone, and 10.66% and 41.82% for trabecular bone, respectively for relative permittivity and conductivity. The average percentage difference between the relative permittivity and conductivity of reference data and proposed liquid tissue-mimicking mixtures was found to be 7.8% and 9.6% for skin, 0.38% and 14% for muscle, 9.6% and 5% for cortical bone, and 3.4% and 2.4% for trabecular bone, respectively, across 0.5–8.5 GHz. The dielectric properties of the tissue-mimicking mixtures were measured using an open-ended coaxial probe measurement technique across 0.5–8.5 GHz. The liquid tissue-mimicking mixtures are composed of Triton X-100, water, and salt, whereas the solid tissue-mimicking mixtures are composed of carbon black, graphite, polyurethane, and isopropanol. The liquid and solid based tissue-mimicking mixtures are also proposed to mimic the dielectric properties of skin, muscle, cortical bone, and trabecular bone. This paper presents anatomically realistic multi-layered 3D-printed and carbon black-based human calcaneus structure. The tissue-mimicking phantoms play a vital role in preclinical testing of the microwave imaging system. This dielectric contrast can be exploited by microwave imaging for monitoring human bone health.