LAUSR

Purpose Current recommendations suggest that family members should participate in the care of children receiving in-hospital 131I metaiodobenzylguanidine (MIBG) therapy for neuroblastoma. The present study aimed to measure the external radiation exposure and estimate the internal radiation exposure of caregivers during the hospital stay for 131I MIBG therapy. Materials and Methods Caregivers received radiation safety instructions and a potassium iodide solution for thyroid blockade before patient admission. External radiation exposure was determined using a personal pocket dosimeter. Serial 24-hour urine samples were collected from caregivers during the hospital stay. Estimated internal radiation exposure was calculated based on the urine activity. Results Twelve cases (mean age, 6.2 ± 3.5 years; range, 2–13 years) were enrolled. The mean administered activity was 233.3 ± 74.9 (range, 150.0–350.0) mCi. The mean external radiation dose was 5.8 ± 7.2 (range, 0.8–19.9) mSv. Caregivers of children older than 4 years had significantly less external radiation exposure than those of children younger than 4 years (1.9 ± 1.0 vs 16.4 ± 5.0 mSv; P = 0.012). The mean estimated internal radiation dose was 11.3 ± 10.2 (range, 1.0–29.8) &mgr;Sv. Conclusions Caregivers receive both external and internal radiation exposure while providing in-hospital care to children receiving 131I MIBG therapy for neuroblastoma. However, the internal radiation exposure was negligible compared with the external radiation exposure.