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Development and evaluation of a 27 MHz multielectrode current‐source interstitial hyperthermia system
Author(s) -
Kaatee Robert S. J. P.
Publication year - 2000
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.1328388
Subject(s) - hyperthermia , biomedical engineering , imaging phantom , current source , materials science , nuclear medicine , current (fluid) , medicine , electrical engineering , engineering
Hyperthermia is a cancer therapy, which is mostly applied in combination with radiotherapy. The aim of hyperthermia is to increase tumor temperatures to 40 °C−45 °C. One of the heating techniques that has been developed to be combined with afterloading interstitial radiotherapy (IRT) is 27 MHz current‐source interstitial hyperthermia (IHT). A four‐channel version of a current‐source IHT system had been developed to study the effectiveness of interstitial hyperthermia in combination with IRT in tumors growing in the flank of a rat. Temperatures up to 46 °C at the edges of various solid tumors with volumes in the range 1500–2000 mm 3are easily reached within 4–10 min. Furthermore, in a collaboration between the University Hospital Utrecht and the Daniel den Hoed Cancer Center in Rotterdam, a multielectrode current‐source (MECS) IHT‐system for clinical use has been developed. Basically, this system consists of three units. First, the actual heating system, including a 27 MHz electromagnetic power unit and multielectrode applicators. Second, a 196‐channel thermometry system with manganin–constantan thermcouple thermometers. Third, a computer plus treatment control software that provides the connection between the first two units and the operator. The power unit has 2 groups of 32 channels with opposite phase. The power can be controlled separately for each channel. Temperatures are measured with seven‐point thermocouple probes inside applicators or inside extra nonheating catheters. The performance of the MECS‐IHT system was examined, focusing on the efficiency of the power deposition in tissue, the homogeneity of the temperature distribution, and on thermometry accuracy.