Head injury, diagnostic X-rays, and risk of medulloblastoma and primitive neuroectodermal tumor: a Children’s Oncology Group study

Abstract
Objective A comprehensive case–control study was conducted to determine potential risk factors for medulloblastoma/primitive neuroectodermal tumor (PNET), a common brain tumor in children. This analysis evaluated possible associations between previous head injury and ionizing radiation exposure through diagnostic X-rays and medulloblastoma/PNET. Methods Mothers of 318 cases any reason including head injury with medulloblastoma/PNET. A statistically non-significant excess of cases reported having an X-ray for reason other than head injury (OR 2.3, 95% CI 0.91–5.7). When cases that received an X-ray for a common symptom of medulloblastoma/PNET were considered unexposed this association weakened (OR: 1.3, 95% CI: 0.49–3.7). No dose–response relationship was observed. Conclusions Head injury and exposure to diagnostic head X-rays were not associated with medulloblastoma/PNET in this study. Future studies should investigate all imaging procedures with ionizing radiation exposure including computed tomography scans and utilize radiation dose estimations.