Cephus E. Simmons RRA, Abstract Co-Author: Nothing to Disclose

Christopher Joseph Erikson MD, , Presenter: Nothing to Disclose

Jeanne Griffin Hill MD, Abstract Co-Author: Nothing to Disclose

Wenjun He, Abstract Co-Author: Nothing to Disclose

Eugene Mah, Abstract Co-Author: Nothing to Disclose

Walter Huda PhD, Abstract Co-Author: Research support, Siemens AG

There is an increasing clinical demand for the modified barium swallow study (MBSS) in the pediatric population. Unfortunately, in addition to the oropharynx, proximal esophagus and airway, the radiation sensitive thyroid gland is in the center of the fluoroscopic field of view.  The purpose of this study, therefore, is to quantify thyroid radiation doses, and the corresponding risks, to pediatric patients undergoing MBSS.

We acquired data on 200 consecutive pediatric MBSS patients. Data were obtained on the Kerma Area Product (mGy-cm2) and fluoroscopic exposure times (minutes). Values of KAP were converted into to thyroid doses using patient age specific thyroid absorbed dose per unit KAP factors calculated using the PCXMC 2.0.1 patient dosimetry software package. Thyroid doses were converted into cancer risk estimates using age and sex specific radiation risk factors published in BEIR VII. All male and female data were combined and presented as a median value with 10th and 90th values presented in brackets [i.e., 10th percentile; 90th percentile].

Just over half the patient sample size was females (105), with the remaining 95 being males. The patient median age was 1.0 years [0.1; 8.5]. Median fluoroscopy time was 1.8 minutes [0.8 min; 3.5 min], and median Kerma Area Product was 130 mGy-cm2 [60 mGy-cm2; 350 mGy-cm2]. Median thyroid dose was 2.3 mGy [0.8 mGy; 6.1 mGy] with a median thyroid cancer risk of 3.2 per 100,000 patients [1.1 per 100,000; 9.5 per 100,000]. The median thyroid cancer risk in female patients was 78% higher than the risk in male patients because of the higher radiosensitivity of the thyroid gland in females.

We conclude that risks of thyroid cancer to pediatric patients undergoing MBSS are very low (i.e., < 0.01%).

The potential longterm radiation risks of thyroid cancer associated with the increasingly utilized MBSS in children are low.  

Simmons, C, Erikson, C, Hill, J, He, W, Mah, E, Huda, W, Thyroid Cancer Risks to Pediatric Patients Undergoing Modified Barium Swallow Studies (MBSS).  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9009394.html