Background Pre-natal or early childhood exposure to medical radiation used in diagnosis or treatment is an identified risk for childhood cancers, but can be difficult to document. The author developed a family questionnaire/interview form to identify possible exposures.

Aims This retrospective study examines pre-natal and early childhood medical radiation exposure in a cohort of children diagnosed with a solid tumour from 2005–2015 at the Children’s Hospital of Pittsburgh (CHP). The hospital is a tri-state regional referral centre which treats about 150–180 new cases of cancer in children per year. About 60% are diagnosed with a solid tumour.

Methods Each consented family so far (approximately 50% of the cohort) has been interviewed in person or by phone call. Medical staff and psycho-social staff referred patient families for interview with the author.

Results Among the families interviewed to date, at least one medical radiation exposure has been identified (pre-conception, pre-natal, or early childhood) in over 70% of diagnosed children. These exposures have included pre-conception sinus or chest CT or x-ray in either parent, sinus CT, or x-ray in mother of diagnostic radiation of chest or abdomen in children.

Conclusions Exposures to medical radiation for a child later diagnosed with cancer may occur at several critical junctures. These exposures may well contribute to a ’perfect storm’ in the still elusive causes of childhood cancer. The author plans to expand the study from 1980 to present to hopefully further document these junctures.