Proton Radiotherapy to Reduce Late Complications in Childhood Head and Neck Cancers

Abstract

In most childhood head and neck cancers, radiotherapy is an essential component of treatment; however, it can be associated with problematic long-term complications. Proton beam therapy is accepted as a preferred radiation modality in pediatric cancers to minimize the late radiation side effects. Given that childhood cancers are a rare and heterogeneous disease, the support for proton therapy comes from risk modeling and a limited number of cohort series. Here, we discuss the role of proton radiotherapy in pediatric head and neck cancers with a focus on reducing radiation toxicities. First, we compare the efficacy and expected toxicities in proton and photon radiotherapy for childhood cancers. Second, we review the benefit of proton radiotherapy in reducing acute and late radiation toxicities, including risks for secondary cancers, craniofacial development, vision, and cognition. Finally, we review the cost effectiveness for proton radiotherapy in pediatric head and neck cancers. This review highlights the benefits of particle radiotherapy for pediatric head and neck cancers to improve the quality of life in cancer survivors, to reduce radiation morbidities, and to maximize efficient health care use.

Keywords: neoplasms, radiation-induced; proton therapy; radiotherapy; radiotherapy, intensity-modulated.

Figure 1.

Comparison of IMPT and VMAT dose distributions. IMPT (left) and VMAT (right) plans with isodose line plans (right). Isodose lines: green: 5640 cGy; orange: 4320 cGy. Abbreviations: cGy, centigray; IMPT, intensity-modulated proton therapy; VMAT, volumetric-modulated arc therapy. Reproduced with permission from Chen et al [13].

Figure 2.

Comparison of VMAT, PPBS, and VHEE planning. (a–d) Coronal images through PTV for the different modalities: (a) VMAT, (b) PPBS, (c) 100 MeV VHEE and (d) 200 MeV VHEE. (e) mean doses to the spinal cord, parotid glands, oral cavity, and brain stem, (f) dose volume histogram for the PTVs and brain stem. Abbreviations: PPBS, proton pencil-beam scanning; PTV, planning target volume; VHEE, very high energy electron; VMAT, volumetric-modulated arc therapy. Reproduced with permission from Schuler et al [74].