Proton Beam Therapy for Pediatric Brain Tumor

Abstract

Cancer is a major cause of childhood death, with central nervous system (CNS) neoplasms being the second most common pediatric malignancy, following hematological cancer. Treatment of pediatric CNS malignancies requires multimodal treatment using a combination of surgery, chemotherapy, and radiotherapy, and advances in these treatments have given favorable results and longer survival. However, treatment-related toxicities have also occurred, particularly for radiotherapy, after which secondary cancer, reduced function of irradiated organs, and retarded growth are significant problems. Proton beam therapy (PBT) is a particle radiotherapy with excellent dose localization that permits treatment of liver and lung cancer by administration of a high dose to the tumor while minimizing damage to surrounding normal tissues. Thus, PBT has the potential advantages for pediatric cancer. In this context, we review the current knowledge on PBT for treatment of pediatric CNS malignancies.

Keywords: brain; children; pediatric; proton beam therapy; proton radiotherapy.

Fig. 1

(a) 3-year-old boy had a parietal lobe tumor. (b) Tumor excision was performed and was diagnosed as an anaplastic ependymoma. Postoperative proton beam therapy was started 37 days after surgery. (c and d) A dose of 59.4 GyE in 33 fractions was initially administered to the tumor bed. Normal brain outside the blue line was completely avoided. So in theory, late toxicity and secondary cancer were prevented by PBT in the area.