Abstract
This study aims to investigate the incidence of acute mastoiditis in patients with brain metastases undergoing whole-brain radiotherapy (WBRT). A retrospective analysis was conducted on patients with brain metastases who received different doses of WBRT. The incidence of acute mastoiditis within 6 months post-radiotherapy was observed. Patients were divided into four groups based on the radiation dose: 25, 30, 36 and 40 Gy. The incidence of mastoiditis in each group was statistically analyzed. A total of 209 patients were followed up, with no cases lost to follow-up, and the follow-up time was 6 months. The results showed that the number of patients with middle ear mastoiditis was 6 (24%) in group A, 101 (67%) in group B, 12 (80%) in group C and 15 (83%) in group D, and there was a statistically significant difference between the four groups (χ(2) = 22.525, p < 0.001). The incidence of acute mastoiditis in patients with brain metastases post-WBRT is positively correlated with the radiation dose. Higher doses not only increase the risk of mastoiditis but also potentially lead to more severe damage to the middle ear and mastoid regions. Therefore, careful dose management and preventive measures are recommended in WBRT planning to reduce the risk of such complications.