Proton Radiation Therapy for the Treatment of Pediatric Retinoblastoma

photocoagulation, and thermotherapy. Following plaque radiation therapy, there was a total of 33/255 recurrences (12.9%), with 26/33 recurrences occurring within the first year. The median time to recurrence was 4.5 months. Sixty-five patients (25.5%) underwent enucleation due to poor vision, pain or viable tumor, with 44/65 of the surgeries occurring within the first year and 18/65 within 5 years after plaque treatment. The median time to enucleation was 7 months. The actuarial local recurrence rates at 1 year, 5 year, and 10 year were 10.2%, 11.8%, and 12.2%, respectively, while actuarial rates for enucleation were 17.3%, 24.3% and 24.7%, respectively. Radiation-related complications included cataracts (n Z 64), non-proliferative retinopathy (n Z 46), maculopathy (n Z 26), retinal neovascularization (n Z 25), glaucoma (n Z 9), and vitreous hemorrhage (n Z 2). Conclusions: Plaque radiation therapy is effective for the management of retinoblastoma with 88% tumor control at 10 years. The choice of iodine125 provides deeper tumor penetration compared to other focal organpreserving therapies, yet limits full ocular and systemic exposure, resulting in beneficial local control. The majority of local failures occur within the first year after plaque brachytherapy. ICRB groups B and C are the bestsuited candidates (basal diameter less than 16 mm and thickness less than or equal to 9 mm). Author Disclosure: N.R. Patel: None. J. Emrich: None. N. Ghodasara: None. F. Troicki: None. L. Komarnicky-Kocher: None. C.L. Shields: None. S. Kaliki: None. A. Mashayekhi: None. S.E. Lally: None. J.A. Shields: None.