Background: Deep inspiration breath-hold (DIBH) has been established to decrease normal tissue radiation dose in breast cancer. Methods: Forty-nine patients had two CT scans during DIBH or free breathing. Chest-wall position, setup verification and breath-hold monitoring were performed. Cone-beam CT and a surface image system were used for verification. Results: A total of 1617 breath-holds were analyzed in 401 fractions. The mean time bit was 6.01min. The mean breaths-holds per fraction was 4.96. The median for intra-breath hold variability was 3mm. No patient stopped treatment for intolerance. Clinical target volume margins were calculated as 0.36, 0.36and 0.32 for the three translational positions. The mean saved volume was 26.3%. Conclusion: Voluntary DIBHis feasible, tolerableand easy to apply for children with Hodgkin lymphoma involving the mediastinum.