Deep inspiration breath-hold (DIBH) is a simple radiotherapy technique, which could have a dramatic impact on late effects in children. In DIBH, the radiotherapy is delivered while the patient holds his/her breath (defined as 4 to 6 sequential breath-holds of ≥20 sec). In deep inspiration, the patient anatomy is changed and imaging artifacts from respiratory movement are diminished as the organs are not moving. Radiotherapy in DIBH can reduce the irradiation of the heart, breasts, and lungs without impacting the delivered radiation dose to the tumor and with no detriment to other healthy organs. Also, the technique is simple and cost-efficient. DIBH is widely used throughout the world in adult patients with left-sided breast cancer and with mediastinal lymphoma to minimize the risk of radiation-induced late effects.