Introduction Currently, medical workers represent the largest group of workers occupationally exposed to ionizing radiation (IR), reaching 7.4 million practitioners worldwide. The risk of radiation associated cancer is still under debate for low-doses IR exposures for these professionals. Some publications have reported an excess of central nervous system (CNS) tumors in interventional cardiologists, but the link with the profession has never been established in a large, properly controlled epidemiological study.

Objectives The ORICAMs (Occupational Radiation-Induced Cancer in Medical Staff) nested case-control study aims to assess the dose-response relationship between IR exposure and CNS tumor.

Methods This study includes medical workers with at least one dosimetric record in the national dose registry called SISERI (Système d’Information de la Surveillance de l’Exposition aux Rayonnements Ionisants) between 2002 and 2012. Follow-up ended in 2019. Individual cumulative doses for each worker will be provided by SISERI. CNS death cases will be matched 1:5 by gender, year of birth, and date of enrollment, with controls alive at the time of case death. Associations between CNS cancer death and cumulative dose will be investigated using conditional logistic regressions.

Results The study will quantify the relationship between occupational exposure to low doses of IR and CNS tumor mortality risks in medical workers. The inclusion of 45 CNS cases and their matched controls will allow detecting at least an odds ratio of 1.5 for a statistical power of 80% and an alpha significance level of 5%.

Conclusion This study will improve the knowledge of the health risks associated with repeated low-dose IR exposures and will contribute to improve radiation protection strategies for medical workers. This cohort will be part of the international BECOME (Brain cancEr risk in pooled Case-cOntrol study of MEdical workers) project, which will address the same objectives, but using joint analyses of data from France, South Korea and the United States.