Alterations in hypothalamic-pituitary axis (HPA) hormones 6 months after cranial radiotherapy in adult patients with primary brain tumors outside the HPA region

Background Cranial radiotherapy is a common treatment for brain tumors, but it can affect the hypothalamic-pituitary (H-P) axis and lead to hormonal disorders. This study aimed to compare serum levels of HPA hormones before and after cranial radiation. Materials and methods This study involved 27 adult patients who underwent brain tumor resection before the initiation of radiotherapy, and none had metastatic brain tumors. All participants had the HPA within the radiation field, and their tumors were located in brain areas outside from the HPA. Serum levels of HPA hormones were recorded both before and 6 months after cranial radiotherapy. Results A total of 27 adult patients, comprising 16 (59.3%) males and 11 (40.7%) females, with a mean age of 56.37 ± 11.38 years, were subjected to evaluation. Six months post-radiotherapy, serum levels of GH and TSH exhibited a significant decrease. Prior to radiotherapy, a substantial and direct correlation was observed between TSH and FSH ( p = 0.005) as well as LH ( p = 0.014). Additionally, a significant and direct relationship was noted between serum FSH and LH ( p < 0.001) before radiotherapy. After radiotherapy, a significant and direct correlation persisted between TSH and FSH ( p = 0.003) as well as LH ( p = 0.005), along with a significant and direct relationship between serum FSH and LH ( p < 0.001). Furthermore, a significant and direct association was identified between changes in serum GH levels and FSH ( p = 0.04), as well as between serum LH and FSH ( p < 0.001). Conclusion Reduced serum levels of HPA hormones are a significant complication of cranial radiotherapy and should be evaluated in follow-up assessments.