Page 13 - Organ motion in children for high-precision radiotherapy - Sophie Huijskens

radiotherapy. Additionally, with effective chemotherapeutics and improved surgical techniques, the use of radiotherapy has varied over time [23]. Especially, (low risk) leukemia and lymphoma patients no longer receive radiotherapy as standard treatment option. For other cancer types, such as neuroblastomas, Wilms’ tumors, brain or bone cancers, the use of radiotherapy declines moderately or is stable [23, 24]. For those tumor types, radiotherapy, along with surgery and chemotherapy, plays an important role in the treatment.
1.2 | Pediatric radiotherapy
Radiotherapy uses ionizing radiation to kill the tumor cells. The most commonly applied form of radiotherapy is photon therapy, using high energy X-rays (1-20 MeV) and is usually delivered with external beams generated by a linear accelerator (linac) (Figure 1.3). An optimal treatment plan in radiotherapy aims to deliver a sufficiently high dose to kill the tumor while at the same time minimizing doses to surrounding healthy tissues, or organs at risk (OARs). Developing the preferred treatment plan for each individual patient is a complex procedure and requires multidisciplinary collaboration of pediatric oncologists, radiation oncologists, physicists, and radiation therapists.
Figure 1.3 | A linear accelerator (Agility, Elekta AB, Stockholm, Sweden) with integrated kV-CBCT system used for image-guided radiotherapy.
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