Radiation Exposure in the Myelomeningocele Population

Abstract

Radiation-induced carcinoma is known to occur with lower doses of radiation exposure than previously recognized. The myelomeningocele population, because of its complex medical problems, is exposed to relatively high doses of radiation from diagnostic radiographs performed throughout their lives. To quantify the amount of exposure, we have calculated the total lifetime radiographic exposure for patients in a myelomeningocele clinic. Out of a myelomeningocele clinic of 248 patients, 112 were identified who had been followed in the clinic since birth. A retrospective history of radiographic exposure was obtained for each patient by reviewing the hospital X-ray jackets. Using standard radiographic dose tables, calculations of total radiation exposure were performed for each patient. The total skin dose exposure ranged from 3.96 to 171.29 rad with a mean of 42.99 rad (SD 33.58). The total skin dose per year of life ranged from 0.79 to 37.81 rad/year of life with a mean of 6.38 rad/year of life (SD 5.72). The total red marrow dose ranged from 0.3 to 29.04 rad with a mean of 7.02 rad (SD 6.24). The total red marrow dose per year of life ranged from 0.1 to 5.35 rad/year of life with a mean of 1.01 rad/year of life (SD 1.06). These data suggest that the radiation burden from diagnostic radiographs in the myelomeningocele population may ultimately contribute to carcinogenesis, mutagenesis and other radiation damage. Specific strategies for reducing the lifetime radiographic exposure in these patients are discussed in detail.

Diagnostic radiation exposure in children with spinal dysraphism: an estimation of the cumulative effective dose in a cohort of 135 children from The Netherlands

“…The average radiation dose at 18 years of follow-up (50 mSv) was estimated by converting radiological records into radiation dose using standard values. Gaskill and Marlin28 reported on radiation exposure in a paediatric myelomeningocele population, but used skin exposure dose and red bone marrow dose to characterise exposure instead of effective dose. Few studies published in literature report on the cumulative effective dose in paediatric patient populations.…”

Patients exposed to diagnostic head and neck radiation for the management of shunted hydrocephalus have a significant risk of developing thyroid nodules

“…Gaskill and Marlin reported the radiation exposure history for 112 myelomeningocele patients, and found that 100 % of patients exceeded the dose limitation of 0.5 rad/year of the general population, and 53 % of patients exceeded the dose limitation of 5 rad/year for those in occupationally related fields, despite gross underestimates of actual exposure [29]. Specific CT protocols for monitoring hydrocephalus have been developed, minimizing absorbed organ doses to the eyes, thyroid, and skull [24], and the use of rapid sequence magnetic resonance imaging (MRI) for nonemergent evaluation has been recommended [30].…”

Hydrocephalus surveillance following shunt placement or endoscopic third ventriculostomy: a survey of surgeons in the Hydrocephalus Clinical Research Networks

“…The preference for rapid MRI reflects the desire to limit pediatric exposure to ionizing radiation. [23][24][25][26] However, the frequency and modality of surveillance imaging may also be impacted by a patient's insurance coverage, as prior authorization is typically required before obtaining an MRI scan.…”