Background: Tumor response after multimodality
treatment using combination of radiation,
chemotherapeutic drugs and hyperthermia usually
assessed by parameters such as tumor growth delay,
volume doubling time and regression response. The
study herein was conducted to investigate the usefulness
of micronucleus assay for assessing the
multimodality treatment. Materials and Methods: The
induction of micronuclei (MN) in a transplantable
solid tumor grown in inbred Balb/c mice was
analyzed after treating the tumors with cis-platin
(cDDP), radiation (RT) and hyperthermia (HT). Results:
The MN frequency in tumor was measured at 1, 3, 5
and 7 days of post-treatment. On day 1, all the cDDP
and RT groups, except HT treatment produced
significantly higher MN counts from that of the
untreated tumors. Cis-platin treatment resulted in a
dose-dependent linear increase in the frequency of
MN induction on day one. Combination of radiation
with cDDP or HT, as bimodality treatment further
increased the MN counts. In the tri-modality group
(cDDP+RT+HT) the MN counts were not significantly
higher than the bi -modality treatments, however
there was an immediate tumor shrinkage indicating
the contribution of other forms of cell death.
Although, MN counts were declined after day five
post-treatment, remained significantly higher than the
control on day seven-post treatment in hyperthermia
alone or its combination with RT and RT+ cDDP
groups. Conclusion: Micronucleus assay may be
useful for assessing the post-treatment regression
response of resistant tumors, while monitoring the
response of sensitive tumors the parameters such as
apoptosis and necrosis may also contribute
considerably to tumor cell loss contributing
immediate tumor regression. Iran. J. Radiat. Res.,
2009 7 (3): 119-125
Satish Rao B, Uma Devi P. Induction of micronuclei in a transplantable murine tumor after multimodality treatment with cis-platin, radiation and hyperthermia. Int J Radiat Res 2009; 7 (3) :119-125 URL: http://ijrr.com/article-1-563-en.html