Treatment of brain tumours with electroporation and bleomycin in an in vivo rat model

The purpose of the study was to examine the possibilities of
prolonging the life of rats with brain tumours using electroporation only
while conducting impedance scans to evaluate the rate of electroporation.
During the experiments, the treated rats in the first batch had tumors grow
for 14 days and were then given electroporation with 8 + 8 exponential
pulses at 800 v/cm, and 15 micro-F. Three of the animals given electroporation
and bleomycin and one of the animals given electroporation alone died
within three days of treatment. The reason for this may be oedema and
increased intracranial pressure due to the large amount of energy delivered
to the brain. In the second batch of rats given electroporation with 8 + 8
exponential pulses at 800 V/cm but with the lower capacitance setting of
4.5 micro-F, none of the treated rats died within a week after treatment. Among
these rats, the tumors had also grown for only 10 days, thus further
decreasing the risk of critical increases of the intracranial pressure directly
after treatment.
Interpretation of the impedance scans made before and after is made
difficult due to factors such as possible short-circuiting of electrodes due to
bleeding in the operating area. Not counting the rats in the first batch that
died within three days of treatment, the rats treated with electroporation
had a significantly prolonged life compared to controls. These results
combined with results of a prior study of treatment of brain tumors in rats
with electroporation in combination with Bleomycin suggest that this form
of treatment may prolong the life of patients with brain tumours.