Risk factors for cataract after palladium-103 ophthalmic plaque radiation therapy.

Purpose: To examine how tumor characteristics and dose affect cataract development after plaque radiation therapy.

Methods And Materials: Three hundred and eighty-four patients were diagnosed with uveal melanoma and treated with palladium-103 ((103)Pd) plaque radiation therapy. Of these, 282 (74%) inclusion met exclusion criteria for follow-up time, tumor location, and phakic status. Then patient-, ophthalmic-, and radiation-specific factors (patient age, diabetes, hypertension, tumor location, tumor dimensions, and lens dose) were examined (by a Cox proportional regression model) as predictors for the development of radiation-related cataract.

Results: Radiation cataract developed in 76 (24%) of patients at a mean follow-up of 39.8 months (range, 1-192). Patients with anteriorly located tumors were noted to have a higher incidence of cataract at 43.0% (43 of 100 patients) vs. 18.1% (33 cataracts per 182 patients) for posteriorly located tumors (p <0.0001). However, multivariate Cox proportional modeling showed that increasing patient age at time of treatment (p for trend = 0.0003) and higher lens dose (p for trend = 0.001) were the best predictors (biomarkers) for radiation cataract.

Conclusions: Although anterior tumor location, greater tumor height, and increased patient age (at treatment) were associated with significantly greater risk for radiation cataract, dose to lens was the most significant factor.