Proton Beam Therapy for Pediatric Chordomas: State of the Art

Chordomas are a rare form of primary bone tumors arising from clivus, vertebra, and sacrum. Although it usually occurs in adults, children can be affected too. Multidisciplinary treatment is required and is particularly challenging because the chordoma’s proximity to critical structures creates a high risk for significant adverse events. Standard procedure consists of extensive surgery followed by high-dose radiation therapy in excess of 70 Gy. Proton beam therapy has become one of the standard procedures to achieve high, local intensity while maximally sparing normal tissue in adults and children. Results achieved so far are promising and are superior to what has been achieved with surgery alone or conventional radiation therapy. When compared with modern photon radiation techniques, such as intensity-modulated radiation therapy, proton beam therapy may be of particular interest for children to provide high conformality while reducing the irradiated volume and therefore potentially minimizing the risk for secondary cancer induction. The role of chemotherapy remains to be defined.