Study type: Medical/biological study (experimental study)

Interaction between microwave-induced brain hyperthermia and high dose rate radiation in the BT4 An brain glioma in rats. med. app.

Published in: J Neurooncol 1996; 27 (3): 205-214

Aim of study (acc. to author)

The cerebral BT4An glioma model in rats was used to investigate the effect of hyperthermia given in combination with radiotherapy in the treatment of brain tumours (thermoradiotherapy). Local brain hyperthermia was given at 42.4°C for 45 min by externally applied microwaves, immediately before radiotherapy (10 Gy). The aim of the study was to determine if a survival benefit can be achieved without unacceptable side-effects by adding local hyperthermia to a single dose of radiation.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 700 MHz
Exposure duration: 45 min
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Exposure 1

Main characteristics
Frequency 700 MHz
Type
Exposure duration 45 min
Exposure setup
Exposure source
  • BSD-1000 system connected to local built applicator with an aperture of 2 cm x 3 cm.
Parameters

No parameters are specified for this exposure.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

In the pilot study, thermoradiotherapy increased the median life span with 20 days compared to controls, which was significantly better than that found after radiotherapy alone (7 days).
In the extended experiment the corresponding figures for thermoradiotherapy, hyperthermia alone and radiotherapy alone were 12.5, 3.5, and 3.5 days, respectively, that means that thermoradiotherapy was significantly better than radiotherapy and hyperthermia alone. Neurological side-effects were infrequent, of slight degree and reversible.
The present study demonstrates that a survival benefit of adding hyperthermia to radiotherapy can be achieved without unacceptable neurological side-effects in an animal glioma model.

Study character:

Study funded by