Hyperthermic treatment of intraocular tumors
P. T. Finger, S. Packer, P. P. Svitra, R. W. Paglione, J. Chess and D. M. Albert
A 5.8-gigahertz (GHz) ophthalmic microwave applicator was used to treat
choroidal melanoma (Green strain) in rabbits. High-frequency
electromagnetic radiation provides a favorable dose distribution to induce
local hyperthermia in the treatment of intraocular tumors. Heating of the
neoplasm, while sparing normal ocular structures, is best accomplished by a
transscleral approach. A hyperthermia plaque is placed on the sclera at the
base of the intraocular tumor. Contact (resistive) heating and
electromagnetic radiation (radiofrequency and microwave) are best suited to
a plaque technique. The advantages of electromagnetic heat induction, as
compared with contact heating, are twofold: the depth of hyperthermic
penetration can be modulated by frequency selection, and the tissues with
low water content (sclera) remain relatively unaffected by microwaves. The
5.8-GHz ophthalmic microwave applicator satisfies the requirements for
local hyperthermic treatment of intraocular tumors.
