Palladium-103 plaque therapy for multifocal iris melanoma: Radiation of the entire anterior segment of the eye.

Purpose: To investigate the safety and tolerability of total anterior segment palladium-103 (Pd) eye plaque brachytherapy for multifocal iris melanoma.

Methods: Interventional case series of 11 patients with multifocal iris melanomas. Anterior segment ultrasound revealed tumor size, location, and intraocular margins. Epicorneal amniotic membrane grafts protected the cornea and decreased pain during total anterior segment 103-Pd ophthalmic plaque brachytherapy.

Results: Eleven diffuse iris melanomas were American Joint Committee on Cancer 8th edition-classified as T1 (n = 5, 45.5%) and T2 (n = 6, 54.5%). Plaque radiation was completed to a minimum mean tumor dose of 85 Gy (mean dose rate, 58.1 cGy/h). Ultrasonographic tumor thickness regression was 41% (follow up mean 58.7, median 50, range: 8-139 months). Despite 100% local control and 100% eye retention, one patient (9.1%) developed metastatic disease. Four eyes required cataract surgery. There was no corneal stem-cell deficiency, corneal opacity, radiation maculopathy, or optic neuropathy. While visual acuity prior to treatment was 20/40 or better in 10 (91%), 9 were 20/40 or better (81.9%) at last follow-up. Four (36%) had glaucoma prior to treatment and three eyes developed glaucoma after treatment for a total of 63%.

Conclusion: Total anterior segment (Pd) plaque brachytherapy resulted in local control, good visual acuity, eye and life preservation in the treatment of multifocal iris melanoma.