Study type: Medical/biological study (experimental study)

Enhancement of Anticancer Drug Delivery to the Brain by Microwave Induced Hyperthermia. med./bio.

Published in: Bioelectrochem Bioenerg 1998; 47 (2): 259-264

Aim of study (acc. to author)

To examine the effect of selective microwave hyperthermia on the transport of MTX (methotrexate) across blood-brain barrier. MTX is a prescribed antifolate in cancer chemotherapy for a variety of neoplasms. MTX concentration in brain tissue with or without microwave hyperthermia was compared. Animals received MTX immediatelay, 15, or 45 min following microwave hyperthermia treatment.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.45 GHz
Modulation type: CW
Exposure duration: continuous for 20 min
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Exposure 1

Main characteristics
Frequency 2.45 GHz
Type
Exposure duration continuous for 20 min
Modulation
Modulation type CW
Exposure setup
Exposure source
  • 7 mm circular dielectrically loaded coaxial applicator.
Setup Rats were immobilized in a streotaxic head holder with the MW applicator placed on top of the holder in such a way that the left hemisphere of the brain was exposed.
Parameters

No parameters are specified for this exposure.

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The average uptake at the posterior left hemisphere was 2.25 +/- 0.43, 10.40 +/- 2.59, and 17.23 +/- 1.13 µg of MTX per gram of brain tissue for 50, 100, and 200 mg/kg doses, respectively. Brains of rats injected 45 min after exposure were free of MTX. Rats euthanized 15 min post-irradiation had an average midbrain MTX concentration of 2.5 +/- 0.46 µg of tissue. These data indicate that MTX uptake is significantly increased in brains subjected to noninvasive microwave hyperthermia treatment. Furthermore, the increase is reversible within 45 min post-exposure.

Study character:

Study funded by