Microwave intracavitary applicator using 434 MHz conformal patch antennas for hyperthermia treatment of gynaecological cancers

Abstract

Feasibility of a 434 MHz microwave intracavitary applicator with conformal patch antennas is presented for hyperthermia treatment of gynaecological cancers. 3D numerical modelling was used to design a 434 MHz resonant conformal rectangular patch on a cylindrical alumina substrate. A conformal array applicator designed using four conformal patch antennas was evaluated in muscle tissue phantom. Applicator measurements indicated that the conformal patch resonated at 434 MHz with power reflection coefficient ρ < −35 dB, penetration depth of 12 mm at 434 MHz and −10 dB bandwidth >40 MHz. Normalised power deposition in the applicator transverse (X Y) plane yielded 25% Effective Field Size (EFS) of 180 and 175 mm 2 in simulation and measurement, respectively, for excitation of single conformal patch. The 25% EFS for excitation of two antennas was 500 and 510 mm 2 in simulation and measurement, respectively. Simulations and measurements suggest that the 434 MHz intracavitary microwave applicator with conformal patch antennas could be used to deliver adjustable and localised power deposition at the target sparing the surrounding healthy tissues.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

A sub 1 GHz ultra miniaturized folded dipole patch antenna for biomedical applications

“…( 1 ) holds valid for the assumption that the metabolic rate will not increase and there is no heat loss due to blood circulation and thermal diffusion in time t . SAR can also be calculated from the information of the Electrical field as 28 : where, Conductivity of the tissue, Tissue Density, Electric Field radiated in the tissue.…”

“…A microwave applicator for the treatment of gynecological cancers was suggested in Ref. 28 at 434 MHz. PD of 12 mm while EFS of 180 mm was achieved.…”

Development of a metamaterial‐based compact applicator for hyperthermia

“…Noninvasive applicators are applied outside the body without any interstitial procedure. Further, it is classified into two groups, a single microwave applicator 4,5 and a radiofrequency (RF) phased array of antennas 5,6 . The drawbacks of microwave applicators are their fixed aperture size, bulkiness, high cost, and penetration depth (PD) only up to 20–30 mm from the skin surface.…”