An iridium 192 wire mold that can bracket and irradiate a large malignant melanoma of the choroid may provide an alternative to enucleation of the affected eye.
The mold, discussed at the recent annual meeting of the American Society of Therapeutic Radiologists in Orlando, Fla, is being used experimentally at the Princess Margaret Hospital in Toronto. Its present application is in patients whose tumors are too large or inappropriately located to be treated with external beam radiation or cobalt 60 plaques.
Generally, large tumors anterior to the equator of the eye are hard to treat effectively with more conventional radiation sources because external radiation from an anterior aspect may damage the lens itself.
Clinical physicist Barbara Japp, BSc, told the meeting that the wire mold—surgically implanted over the base of the tumor (which usually is growing pyramid-like into the eye) and left in place for five to seven days—can be