RT Journal Article SR Electronic T1 Proton beam radiotherapy of diffuse iris melanoma in 54 patients JF British Journal of Ophthalmology JO Br J Ophthalmol FD BMJ Publishing Group Ltd. SP 812 OP 816 DO 10.1136/bjophthalmol-2014-305174 VO 99 IS 6 A1 Willerding, Gregor D A1 Cordini, Dino A1 Hackl, Christoph A1 Karle, Bettina A1 Lakotka, Nona A1 Foerster, Michael H A1 Bechrakis, Nikolaos N A1 Heufelder, Jens A1 Moser, Lutz A1 Joussen, Antonia M YR 2015 UL http://bjo.bmj.com/content/99/6/812.abstract AB Background Treatment modalities in iris melanoma include excision, plaque radiotherapy, photon or proton beam therapy and enucleation. In extensive tumours and diffuse seeding, radiotherapy remains as an alternative to enucleation. Methods This study is a retrospective, consecutive, interventional, single-institutional case series. 54 patients with a diffuse and non-resectable iris melanoma diagnosed from September 1998 to June 2012 were included. A 68-megaelectron volt proton beam was used to treat the anterior segment with a total dose of 4×12.5 cobalt grey equivalent. The cases were evaluated for local tumour control, eye retention, functional outcome and local complications after treatment. Results During a mean follow-up of 62.7 months (median 54.8 months, range 5.5–159.6 months), local tumour control was achieved in 96.3% of the patients. Cataract and glaucoma were the main complications developing after irradiation in 42.6% and 55.6%, respectively. In 34 of 44 patients (77.3%) who underwent cataract removal, a visual acuity of 20/40 or better following surgery was preserved. Enucleation was performed in three patients. The reason was suspected tumour recurrence in one and glaucoma in two. Hepatic metastasis occurred in one patient. Conclusions As an alternative to enucleation, whole anterior segment fractionated proton beam radiotherapy offered excellent local tumour control in diffuse iris melanoma. Given the limited alternatives, the rate of complications appears acceptable and visual function could be preserved in the majority of the patients during follow-up.