Diagnostic radiological examinations and risk of intracranial tumours in adults – Findings from the Interphone Study

Background: Exposure to high doses of ionizing radiation is among the few wellestablished brain tumour risk factors. We used data from the Interphone study to
evaluate the effects of exposure to low-dose radiation from diagnostic radiological
examinations on glioma, meningioma and acoustic neuroma risk.
Methods: Brain tumour cases (2644 gliomas, 2236 meningiomas, 1083 neuromas) diagnosed in 2000–02 were identified through hospitals in 13 countries, and 6068 controls
(population-based controls in most centres) were included in the analysis. Participation
across all centres was 64% for glioma cases, 78% for meningioma cases, 82% for acoustic neuroma cases and 53% for controls. Information on previous diagnostic radiological
examinations was obtained by interviews, including the frequency, timing and indication
for the examinations. Typical brain doses per type of examination were estimated based
on the literature. Examinations within the 5 years before the index date were excluded
from the dose estimation. Adjusted odds ratios were estimated using conditional logistic
regression.
Results: No materially or consistently increased odds ratios for glioma, meningioma or
acoustic neuroma were found for any specific type of examination, including computed
tomography of the head and cerebral angiography. The only indication of an elevated
risk was an increasing trend in risk of [...]