Bromodeoxyuridine uptake in the assessment of hyperthermic therapy for intraocular tumor

N. Kindy-Degnan, D. H. Char, P. Swift, S. Kaleta and B. M. Ljung
Department of Ophthalmology, University of California, San Francisco 94143.

Assessment of uveal melanoma response after many nonenucleation therapies is difficult with current modalities, since tumor regression is usually delayed. The goal of most treatments, including ionizing radiation or radiation and adjunct hyperthermia, is to destroy the reproductive capacity of the tumor. Cell cycling analysis with bromodeoxyuridine, a thymidine analogue only incorporated during DNA synthesis, was a useful indication of tumor control after hyperthermia was used to treat a Greene intraocular melanoma model. Cell cycling decreased from a mean of 16% before therapy to less than 1% in all the successfully treated tumors. Cell cycling changes preceded histologic evidence of cell death. In contrast, tumors that grew after insufficient treatment had increased cell cycling to a mean of 25%. Cell cycling studies with bromodeoxyuridine represent a sensitive gauge of the reproductive integrity of the tumor.