The last ailment we shall discuss in this section is the accumulation of
large quantities of excess fluid in the chest and abdominal cavities
from their linings, as a consequence of the growth of certain types of
malignant tumors.
Frequent surgical drainage was at one time the only very useful
treatment, and of course this was both uncomfortable and dangerous. The
use of radioactive colloidal suspensions, primarily colloidal gold-198,
has been quite successful in palliative treatment: It does not cure, but
it does give marked relief.
[Illustration: Showing:]
Colloidal gold in shield
Saline solution
To peritoneal or pleural cavity
Radioactive colloids (a colloid is a suspension of one very finely
divided substance in some other medium) can be introduced into the
abdominal cavity, where they may remain suspended or settle out upon the
lining. In either case, since they are not dissolved, they do not pass
through the membranes or cell walls but remain within the cavity.
Through its destructive and retarding effect on the cancer cells the
radiation inhibits the oozing of fluids.
Gold-198 offers several advantages in such cases. It has a short
half-life (2.7 days); it is chemically inert and therefore nontoxic; and
it emits beta and gamma radiation that is almost entirely absorbed by
the tissues in its immediate neighborhood.
The results have been very encouraging. There is admittedly no evidence
of any cures, or even lengthening of life, but there has been marked
reduction of discomfort and control of the oozing in over two-thirds of
the cases treated.