Multifield brachytherapy for multifocal retinoblastoma

Multifocal retinoblastoma (RB) is the most severe course variant of this disease, incidence among patients with binocular RB 67-70%. Despite high rates occurrence form in clinical practice, there no information literature about efficacy its treatment using brachytherapy (BT) and various modifications (multifield BT, simultaneous two plaques). The safety repeated irradiation unexplored. aim study to evaluate multifield BT multifocal RB. Materials methods: period from 2007 2021 was used as a local for 136 (146 eyes), them 42 (46 eyes – 106 tumors) were treated by BT. mean age at time 26.8 months (range, 6-67 months). Irradiation performed following variants: fields 36 eyes, three 8 four 1 eye, five eye. plaques different parts fundus 6 (6 sequential displacement plaque neighbouring or opposite zone - 15 (15 eyes). Results: complete tumor regression achieved 70% (n=74), partial 22% (n=23). Progressive disease observed 7% (n=8), recurrence 4 after 1% (n=1). Local control 92% cases. only preserved 90% BT-related complications 48% cases (22 eyes) follow-up 55 3-157 A comparative analysis single-field additionally, result shown that allows achieve comparable (94%; p= 0.128) clearly greater number (46%; p=0.02), which does not significantly affect eye-retention rate (83%; p=0.16). Conclusion: has relative