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.