A 20-year audit of retinoblastoma treatment outcomes

Objectives To evaluate the long-term treatment outcomes in intraocular retinoblastoma (RB) including the associated factors for eventual treatment with external beam radiotherapy (EBRT) and enucleation as well as to analyse the risk factors for metastasis and death in extraocular RB. Methods Retrospective analysis of 390 eyes from 256 (89.8%) intraocular RB and 29 (10.2%) extraocular RB cases diagnosed and treated between October 1998 and May 2018 at one of the largest tertiary care centers in Turkey. Results Of 351 intraocular RB eyes, 53.3% had group D/E disease at presentation. 75 (21.4%) of 351 eyes underwent primary enucleation. Of the remaining 276 eyes undergoing eye-conserving treatments, 201 (72.8%) were salvaged. Most of these eyes were treated using intravenous chemotherapy and/or focal treatments [transpupillary thermotherapy (TTT) and cryotherapy] initially. EBRT was eventually required in 48 (17.4%) eyes and secondary enucleation in 75 (27.2%) eyes. At mean follow-ups of 76.7 and 39.7 months for intraocular and extraocular RB cohorts, respectively, 180 (46.2%) eyes underwent primary/secondary enucleation and exenteration. Overall, 13 cases developed metastasis and 9 died. Two patients with trilateral RB also expired. Multivariable risk factors for enucleation were the presence of vitreous seeds (p < 0.001), absence of EBRT administration (p = 0.033), 5-9 TTT applications compared with no TTT (p = 0.031), and each 1 mm increase in tumour base diameter (p < 0.001). Univariate factors predictive of metastasis were the presence of extraocular RB detected by imaging methods (p < 0.001) and extrascleral/optic nerve cut end involvement at histopathological examination (p < 0.001). Conclusions In our series, 72.8% of the intraocular RB eyes undergoing eye-conserving treatments were saved. The globe salvage rate for all intraocular and extraocular RB eyes was 53.8% and the overall survival rate was 96.1%.