Low serum 25‐hydroxyvitamin D3 levels and late delayed radiation‐induced brain injury in patients with nasopharyngeal carcinoma: A case–control study

BACKGROUND AND PURPOSE: Inflammatory reaction plays a critical role in the pathogenesis of late delayed radiation‐induced brain injury (RBI). Low vitamin D levels are closely associated with various immuno‐inflammatory diseases, but the relationship with late delayed RBI remains unknown. Here, we aimed to determine the association of serum vitamin D levels with clinical parameters in late delayed RBI patients with nasopharyngeal carcinoma. METHODS: 25‐Hydroxyvitamin D3 levels and clinical and cerebrospinal fluid parameters were evaluated in 21 patients with RBI and compared with 90 age‐, sex‐, and season‐matched healthy controls. RESULTS: 25‐(OH)D3 levels were lower in patients with RBI compared to controls (40.39 ± 22.11 vs. 64.54 ± 19.89 nmol/L, p < .001), especially for aged ≥60 years (vs. <60 years, p = .038), females (vs. males, p = .012), short latency (<5 years) (vs. ≥5 years, p = .015), and severe impairment (LENT/SOMA score ≥3) (vs. LENT/SOMA score <3, p = .010). Serum 25‐(OH)D3 levels were associated with age (r = −.464, p = .015), Latency of RBI (r = .416, p = .031) and LENT/SOMA Scale (r = −.488, p = .010). CONCLUSIONS: Our data showed that serum 25‐(OH)D3 levels were reduced in late delayed RBI patients with nasopharyngeal carcinoma.