Performance characteristics of a conformal ultra‐wideband multilayer applicator (CUMLA) for hyperthermia in veterinary patients: a pilot evaluation of its use in the adjuvant treatment of non‐resectable tumours

Abstract

Performance and clinical characteristics of a novel hyperthermia antenna operating at 434 MHz were evaluated for the adjuvant treatment of locally advanced superficial tumours in cats, dogs and horses. Electromagnetic simulations were performed to determine electric field characteristics and compared to simulations for a flat microwave antenna with similar dimensions. Simulation results show a reduced skin surface and backfield irradiation and improved directional irradiation (at broadside) compared to a flat antenna. Radiated power and penetration is notably increased with a penetration depth of 4.59 cm compared to 2.74 cm for the flat antenna. Clinical use of the antenna was then evaluated in six animals with locoregionally advanced solid tumours receiving adjuvant chemotherapy. During clinical applications, therapeutic temperatures were achieved at depths ≥4 cm. Objective responses were seen in all patients; tissue toxicity in one case limited further therapy. This antenna provides compact, efficient, focused and deep-penetrating clinical hyperthermia for the treatment of solid tumours in veterinary patients.

Conformal multilayer hyperthermia applicators for superficial cancer treatment in veterinary patients

“…The near field at 1cm depth provides information on electric field directivity and distribution. In comparison to [3], EFS has been significantly reduced and dropped to 51.2cm 2 from 75cm 2 for 4-patches antenna and even to 31.8cm 2 for the small-size antenna which makes them suitable for small cancerous regions. This EFS drop led to preventing or minimizing the burning of the healthy area around affected tissue as was described in [3].…”

“…Furthermore, they can be designed to focus energy to a targeted region and demonstrate good matching to the tissues. The compact conformal applicator in [3], for example, shows good matching without water bolus and insensitivity to different anatomic sites at 434MHz based on clinical responses of the different animals. However, these compact applicators are not appropriate for small cancerous regions and burn the healthy areas around the damaged tissue.…”