Preliminary results of proton beam irradiation of macular and paramacular melanomas.

Proton beam irradiation has been used for the treatment of 60 eyes with choroidal melanomas located 3 mm or less from the fovea. The average follow-up period was 18 months. 86% of the treated lesions showed regression at the time of this analysis, and the 14% that did not were followed up for less than a year. Visual acuity remained the same in 47% of the treated eyes, improved in 20%, and deteriorated in 33%. 58% of the treated eyes had visual acuity of 20/100 or better at the last follow-up examination. Radiation vasculopathy with macular oedema was the most common complication, and it was observed in 22% of the treated eyes. These preliminary observations suggest that proton beam irradiation may be a reasonable alternative to enucleation even for this group of choroidal melanomas, which is considered unfavourable in respect of the preservation of visual function.