
anodized aluminium grains labelled with radiophosphorus
for medical purposes
g. b. fasolo, r. malvano, u. rosa and e. zimmer
interstitial b-therapy, by implantation in tissues of
radioactive sources, is widely applied to the treatment
of certain forms of human malignancies.  among the
radio-elements proposed for this therapeutic technique,
yttrium-90 and gold-198 are the most generally used.
radiophosphorus (32p) shows some attractive features
because of its suitable half-life (14.3 days) and its rather
high-energy b-emission (maximum energy 1.71 mev);
but the use of this radionuclide is limited by the diffi-
culties found in the preparation of safe solid sources.  the
only techniques we have found in the literature are those
reported by riechert and mundinger and by rames and
moravek, who used respectively small plastic capsules
filled with phosphomolybdic acid solution, and ca(po4),
grains, labelled with phosphorus-32.  these methods
require a delicate preparative work, and, moreover, a
large b-self-absorption effect can be expected in both
cases.
a new simple method for the preparation of grains
labelled with phosphorus-32 basically consists in ad-
sorbing labelled po4 3- ions on an active aluminium oxide
film produced by anodic oxidation of aluminium wire.
the adsorption capacity of the oxide film for po3 3- ions
is quite high, but the process is reversible: the phos-
phorus-32 activity is partially desorbed, even after
'sealing' in boiling water, when the labelled wire is kept
in isotonic sodium chloride solution.
