Retrospective study of cumulative diagnostic radiation exposure during childhood in patients with spina bifida.

BACKGROUND

The Biological Effects of Ionizing Radiation Committee of the National Academy of Sciences in 2005 and other expert panels have warned that risk of cancer increases with higher doses of radiation. Children with spina bifida and hydrocephalus have far greater exposure to radiation than the average person, starting almost directly after birth and continuing throughout their lifetimes.

OBJECTIVE

The purpose of this study was to estimate the amount of ionizing radiation that patients with spina bifida and hydrocephalus are exposed to during childhood from diagnostic imaging.

METHODS

Thirty patients, ages 18 years or older, with spina bifida and hydrocephalus were randomly selected from a spina bifida clinic and their radiology records were reviewed. Descriptive analyses were conducted. The total radiation exposure was then calculated for the study group, and the mean effective dose per patient was determined.

RESULTS

In the study group, during their first 18 years, each patient had a mean of 55.1 studies and a median of 45 radiologic studies, a mean of 9.6 brain CT scans, and a mean cumulative effective dose of 81.9 mSv (2.6 mSv/patient/year over 18 years) and a median cumulative effective dose of 77.2 mSV of accumulated radiation exposure (4.5 mSv/patient/year over 18 years).

CONCLUSIONS

Clinicians should recognize that increased radiation exposure puts patients with spina bifida and hydrocephalus at higher risk for cancer. The population of children and adults with spina bifida and hydrocephalus should be surveyed for incidence of cancer.