To modify the final dose delivered to superficial tissues and to modulate dose distribution near irradiated surface, different boluses are used. Air gaps often form under the bolus affecting dose distribution. This study aimed to evaluate the effect of an air gap under the bolus radiation on dose delivery.

To evaluate the impact of the air gap, both helical tomotherapy (HT) and direct tomotherapy (DT) were performed in a simulation study.

The maximum dose to bolus in DT plans was bigger than that used in HT plans. The maximum dose delivered to the bolus depended on the air gap size. However, the maximum dose to bolus in all HT plans was within the acceptable value range. Acceptable value was set to up to 107% of the prescription dose. In the simulation performed in this study, the acceptable air gap under bolus was up to 15 mm and below 5 mm in HT and DT plans, respectively.

HT technique is a good choice, but DT technique can be also used if the bolus position can be reproduced accurately. Thus, the reproducibility of the bolus position between planning and treatment is very important.

Little is known about the preparedness of hospitals to care for pediatric patients during a major incident in Japan. This study assessed the disaster preparedness of a children’s hospital in Japan by using a disaster drill.

We performed a triage drill with all hospitalized patients. The triage tags and medical records were reviewed retrospectively. We determined the efficacy of triage education, the validity of the Simple Triage and Rapid Treatment (START) method for children, and the potential need for evacuation through the disaster drill.

This study highlights 3 important issues about the hospital’s preparedness. First, it is difficult to promote disaster education for staff who are not well trained on handling disasters. Second, the START method is suitable for children older than 5 years, but it has a high rate of over-triaging among younger children. Third, approximately 40% of patients who are coded as immediate may require transportation resources in a hospital evacuation.

Our findings suggest that disaster preparedness, such as educating hospital staff regarding disasters and establishing evacuation systems for a number of pediatric patients when a disaster happens, is essential for caring for hospitalized children during a mass casualty incident. (Disaster Med Public Health Preparedness. 2019;13:429-432)