Dual-antenna applicator for hyperthermia of tumours at intermediate depth

Abstract

A dual-antenna applicator with 21 ±26 cm² aperture, that is fully loaded and operates at 74 MHz, was developed at the Mallinckrodt Institute of Radiology. By placing two antennas into an applicator capable of propagating TE₁₀ mode, a significant enlargement of heating pattern was achieved without an increase in applicator dimensions. When antennas are placed symmetrically about a parallel to the antenna axis of symmetry, the sensitivity of the applicator input impedance to variations of load impedance reduces. Stable coupling of the RF power to the treatment area may be provided. Twenty patients with eccentrically located tumours were treated using this device.

Key Words:

• Applicator
• electromagnetic
• coupling
• penetration