Results following episcleral ruthenium plaque radiotherapy for posterior uveal melanoma. The Swedish experience.

The Swedish experience of ruthenium 106 plaque radiotherapy for posterior uveal melanoma includes 266 patients treated between 1979 and 1995. The median dose delivered at the tumour apex was 100 Gy and the median follow-up after radiotherapy was 3.6 years (range = 0.5 to 12.5 years) with no patient being lost to follow-up. Visual acuity deteriorated moderately following treatment but appeared to stabilize after 5 to 6 years. Treatment failure defined as enucleation following plaque treatment occurred in 46 of the 266 (17%) studied patients. The cumulative 5-year probability of retaining the eye after radiotherapy was 82% and by univariate analysis tumour height, tumour diameter and tumour stage each predicted subsequent treatment failure, whereas in multivariate analysis no single covariate retained a predictive value. Forty-five of the 266 patients died of any cause during follow-up; 27 of these deaths were melanoma-related. The cumulative 5-year survival proportion (based on melanoma-related deaths only) was 86%. Death in metastatic disease appeared to be more common among patients that failed ruthenium plaque radiotherapy, however these patients also tended to have large tumours.