Comparison of skin dose measurement using nanoDot(®) dosimeter and machine readings of radiation dose during cardiac catheterization in children

OBJECTIVES: Direct measurement of skin dose of radiation for children using optically stimulated luminescence (OSL) technology using nanoDot(®) (Landauer, Glenwood, IL, USA). BACKGROUND: Radiation dose is estimated as cumulative air kerma (AK) and dosearea product based on standards established for adult size patients. Body size of pediatric patients who undergo cardiac catheterization for congenital heart disease vary widely from newborn to adolescence. Direct, skindose measurement applying OSL technology may eliminate errors in the estimate. MATERIALS AND METHODS: The nanoDot(®) (1 cm × 1 cm × flat plastic cassette) is applied to patient's skin using adhesive tape during cardiac catheterization and radiation skin doses were read within 24 hrs. nanoDot(®) values were compared to the currently available cumulative AK values estimated and displayed on fluoroscopy monitor. RESULTS: A total of 12 children were studied, aged 4 months to 18 years (median 1.1 years) and weight range 5.3–86 kg (median 8.4 kg). nanoDot® readings ranged from 2.58 mGy to 424.8 mGy (median 84.1 mGy). Cumulative AK ranged from 16.2 mGy to 571.2 mGy (median 171.1 mGy). Linear correlation was noted between nanoDot® values and AK values (R(2) = 0.88, R = 0.94). nanoDot® readings were approximately 65% of the estimated cumulative AK estimated using the International Electrotechnical Commission standards. CONCLUSIONS: Application of OSL technology using nanoDot® provides an alternative to directly measure fluoroscopic skin dose in children during cardiac catheterization. Our data show that the actual skin dose for children is approximately one-third lower than the AK estimated using international standards for adult size patients.