Radioisotopes have an important role in the treatment of disease,
particularly cancer. It is still believed that cancer is not one but
several diseases with possible multiple causes. Great progress is being
made in development of chemicals for relief of cancer. Nevertheless,
radiation and surgery are still the main methods for treating cancer,
and there are many conditions in which relief can be obtained through
use of radiation. Moreover, the imaginative use of radioisotopes gives
much greater flexibility in radiation therapy. This is expected to be
true for some years to come even as progress continues.
Radioisotopes serve as concentrated sources of radiation and frequently
are localized within the diseased cells or organs. The dose can be
computed to yield the maximum therapeutic effect without harming
adjacent healthy tissues. Let us see some of the ways in which this is
done.