[ RadSafe ] Genuinely beneficial effects of low dose whole-body irradiation

Rainer.Facius at dlr.de Rainer.Facius at dlr.de
Tue Apr 22 12:53:21 CDT 2008

So far I have not seen more intriguing evidence for incontrovertibly
beneficial action of whole-body low dose irradiation (further
potentiated by gene-therapy).

Rainer Facius

Wu N, Jin S-Z, Pan X-N, Liu S-Z.
Increase in efficacy of cancer radiotherapy by combination with
whole-body low dose irradiation
International Journal of Radiation Biology, 84#3(2008)201-210

Purpose: Design of cancer radiotherapy protocol to reduce radiation dose
and increase treatment efficacy in Lewis lung cancer (LLC) model.

Methods: C57BL/6J mice subcutaneously implanted with LLC were treated by
conventional radiotherapy (2Gy 6 6) combined with LDWBI (low dose
whole-body irradiation; the second, third, fifth and sixth local doses
of 2Gy each substituted by LDWBI with 0.075Gy) and/or gene therapy
(intratumor injection of pEgr-IL-18-B7.1 plasmid 24 h before the first
and fourth local doses). Immunologic mechanisms were explored.

Results: Cancer control was most significantly improved in the group
receiving local radiotherapy combined with LDWBI and gene therapy as
shown by prolongation of mean survival time by 60.4%, reduction in
average tumor weight by 70.8%, decrease in pulmonary metastasis by 66.9%
and decrease in intratumor angiogenesis by 64.8% as compared to local
radiotherapy alone (p50.05). These changes in tumor growth and
progression were accompanied with up-regulation of host immunity
manifested by stimulated NK (natural killer) and CTL (cytotoxic T
lymphocyte) activity, IFN (interferon)- gamma and TNF (tumor necrosis
factor)-alpha secretion, PKC (protein kinase C)-theta activation and
LAMP (lysosomal associated membrane protein)-1 expression.

Conclusion: Combination of conventional radiotherapy with LDWBI and gene
transfer could reduce total radiation dose by 2/3 and at the same time
improve treatment efficacy of cancer accompanied with up-regulated host
anticancer immunity. 

Conclusion (full text):
The experimental findings in the present study showed that low dose
whole-body irradiation in combination with local radiotherapy could
improve the tumor control in a mouse lung cancer model, and introduction
of the pEgr-IL-18-B7.1 plasmid into the tumor could further promote the
treatment efficacy to a certain extent. It is important to note that
such an improvement in treatment efficacy was accompanied with a
reduction of total radiation dose to about 1/3 of that in the
conventional radiotherapy regimen. These observations may set the stage
for developing rational clinical protocols in cancer treatment.

Dr. Rainer Facius
German Aerospace Center
Institute of Aerospace Medicine
Linder Hoehe
51147 Koeln
Voice: +49 2203 601 3147 or 3150
FAX:   +49 2203 61970

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