Proton beam radiotherapy of iris melanoma.

St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK.
International Journal of Radiation OncologyBiologyPhysics (Impact Factor: 4.52). 09/2005; 63(1):109-15. DOI: 10.1016/j.ijrobp.2005.01.050
Source: PubMed

ABSTRACT To report on outcomes after proton beam radiotherapy of iris melanoma.
Between 1993 and 2004, 88 patients with iris melanoma received proton beam radiotherapy, with 53.1 Gy in 4 fractions.
The patients had a mean age of 52 years and a median follow-up of 2.7 years. The tumors had a median diameter of 4.3 mm, involving more than 2 clock hours of iris in 32% of patients and more than 2 hours of angle in 27%. The ciliary body was involved in 20%. Cataract was present in 13 patients before treatment and subsequently developed in another 18. Cataract had a 4-year rate of 63% and by Cox analysis was related to age (p = 0.05), initial visual loss (p < 0.0001), iris involvement (p < 0.0001), and tumor thickness (p < 0.0001). Glaucoma was present before treatment in 13 patients and developed after treatment in another 3. Three eyes were enucleated, all because of recurrence, which had an actuarial 4-year rate of 3.3% (95% CI 0-8.0%).
Proton beam radiotherapy of iris melanoma is well tolerated, the main problems being radiation-cataract, which was treatable, and preexisting glaucoma, which in several patients was difficult to control.

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