The Use of Radioactive Phosphorus* in the Detection of Intraocular Tumors
ROSCOE J. KENNEDY, M.D.
Department of Ophthalmology
OTTO GLASSER, Ph.D.
Department of Biophysics
PHILIP KAZDAN, M.D.
INTRAOCULAR tumors often present a difficult diagnostic problem that involves the important decision of whether or not to enucleate an eye. When the eye that is suspect is the better of the two, the decision is critical. Radioactive phosphorus (P32) was used as a diagnostic aid in 24 cases of intraocular lesions. The purpose of this report is to present the findings in this group.
Radioactive phosphorus was used by Low-Beer1 in 1946, in the detection of tumors of the breast. In 1949, Selverstone, Solomon and Sweet2 reported its value in the location of tumors of the brain. As concerns the eye, in 1951 Dunphy and Selberstone3 showed that P32 concentrated in the vascular more than in the nonvascular tissues and intraocular fluids.
The use of P32 intravenously in the detection of intraocular tumors was first reported by Thomas, Krohmer and Storaasli,4 who published findings in eight cases in 1952. Others have since reported their experiences.5–7
P32 is used because it emits a beta radiation that easily can be detected with a Geiger counter. The average range of these beta rays in penetration of tissue is 2 mm., although the most penetrating may travel as deep as 6 mm. The half-life of the isotope is 14.3 days.
Eyes were anesthetized with 0.5 per cent tetracaine (pontocaine) hydrochloride. Five-hundred microcuries (0.5 millicuries) of sterile P32 (in saline solution) was then injected intravenously and counts were started immediately over the suspected area, and a corresponding area in the unaffected eye.