A flexible 70 MHz phase-controlled double waveguide system for hyperthermia treatment of superficial tumours with deep infiltration

Gerard van Stam, H. Petra Kok, Maarten C. C. M. Hulshof, M. Willemijn Kolff, Geertjan van Tienhoven, Jan Sijbrands, Akke Bakker, Paul J. zum Vörde sive Vörding, Sabine Oldenborg, Martijn de Greef, Coen R. N. Rasch, Hans Crezee

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Purpose: Superficial tumours with deep infiltration in the upper 15 cm of the trunk cannot be treated adequately with existing hyperthermia systems. The aim of this study was to develop, characterise and evaluate a new flexible two-channel hyperthermia system (AMC-2) for tumours in this region. Materials and methods: The two-channel AMC-2 system has two horizontally revolving and height adjustable 70 MHz waveguides. Three different interchangeable antennas with sizes 20 × 34, 15 × 34 and 8.5 × 34 cm were developed and their electrical properties were determined. The performance of the AMC-2 system was tested by measurements of the electric field distribution in a saline water filled elliptical phantom, using an electric field vector probe. Clinical feasibility was demonstrated by treatment of a melanoma in the axillary region. Results: Phantom measurements showed a good performance for all waveguides. The large reflection of the smallest antenna has to be compensated by increased forward power. Field patterns become asymmetrical when using smaller top antennas, necessitating phase corrections. The clinical application showed that tumours deeper than 4 cm can be heated adequately. A median tumour temperature of 42 °C can be reached up to 12 cm depth with adequate antenna positioning and phase-amplitude steering. Conclusions: This 70 MHz AMC-2 waveguide system is a useful addition to existing loco-regional hyperthermia equipment as it is capable of heating axillary tumours and other tumours deeper than 4 cm.
Original languageEnglish
Pages (from-to)796-809
JournalInternational journal of hyperthermia
Volume33
Issue number7
Early online date17 Apr 2017
DOIs
Publication statusPublished - Nov 2017
Externally publishedYes

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