Predictors of the therapeutic effect of corticosteroids on radiation-induced optic neuropathy following nasopharyngeal carcinoma

Radiation-induced optic neuropathy (RION) is a severe visual complication resulting from radiotherapy of the head and neck, which mostly occurs in patients with nasopharyngeal carcinoma (NPC) in the southern part of China. The mechanism of RION is unclear. Therefore, identifying risk factors for RION is an important step towards enhancing our understanding. In the current study, we retrospectively reviewed patients with NPC who were admitted to Sun Yat-Sen Memorial Hospital for visual loss between 2006 and 2017. The study included 38 participants (68 eyes) in the corticosteroid-effective group and 35 participants (64 eyes) in the corticosteroids-ineffective group. We analyzed potential risk factors for RION and developed a prediction model for the therapeutic effect of corticosteroid effect based on a random forests method. The prediction model showed a high accuracy with an area under the receiver operating characteristic curve of 0.932 (95% confidence interval = 0.889–0.975). Our results revealed that blood urea nitrogen (BUN) was significantly associated with RION and that RION patients with higher BUN levels responded better to corticosteroid treatment. Altogether, these results suggest that a prediction model, based on clinical factors, could be applied to estimate the therapeutic effect of corticosteroids on RION. Further investigation, however, is needed to confirm the study conclusion.