Histopathologic study of eyes after iodine I 125 episcleral plaque irradiation for uveal melanoma
M. A. Saornil, M. R. Fisher, R. J. Campbell, D. M. Robertson, J. D. Earle, R. C. Eagle Jr, J. A. Shields, C. L. Shields, S. R. Chandra and D. M. Albert
Department of Ophthalmology, Universidad de Valladolid, Spain.
OBJECTIVES: To describe the histopathologic findings attributable to
irradiation in eyes with uveal malignant melanoma treated with iodine I 125
brachytherapy and to compare these findings with those reviewed in a
previous study that compared histopathologic findings in eyes enucleated
after proton beam teletherapy with those seen in eyes in a nonirradiated
control group. METHODS: The slides from 22 eyes with uveal melanoma that
had undergone enucleation after the administration of 125I brachytherapy
were studied. The histopathologic features of the tumor and the retina were
graded. Results were compared with findings from a previously reported
group of 47 proton beam-treated eyes and its control group. RESULTS:
Patient age, time between irradiation and enucleation, and ciliary body
involvement were similar for the 125I brachytherapy-treated group and the
proton beam-treated group and its control group. This allows comparison of
the histopathologic findings. Comparing the 125I brachytherapy- and proton
beam-treated groups, most histopathologic features were similar with
nominally statistically significant differences only for cell type, number
of mitotic figures, and fibrous metaplasia of the retinal pigment
epithelium adjacent to the tumor. CONCLUSIONS: Irradiation of uveal
melanoma induces changes in the tumor and in the surrounding retina.
Brachytherapy and charged particle therapy are the 2 principal methods of
irradiation. This study demonstrates that similar changes are produced by
125I plaque irradiation and proton beam irradiation.
