Pediatric CNS Radiation Oncology: Recent Developments and Novel Techniques

Abstract

Radiation therapy (RT) is a cornerstone in the management of pediatric central nervous system (CNS) tumors. Recent advancements in RT delivery and techniques aim to enhance therapeutic effectiveness while minimizing both acute and long-term complications associated with pediatric brain RT. This paper highlights innovative developments in the field, including the clinical indications, benefits, and challenges of proton therapy and stereotactic radiotherapy. The ongoing refinement of risk-adapted RT volumes is highlighted, with examples of newly proposed germinoma RT volumes and hippocampal-sparing RT. Additionally, emerging experimental approaches, including FLASH therapy and theranostics, are also discussed as promising future directions. Further prospective, multi-institutional collaborative studies are essential to validate and expand upon the benefits outlined in this review.

Keywords: brain radiotherapy (RT); pediatric central nervous system (CNS) tumor; pediatric radiotherapy (RT); proton therapy.

Figure 1

Example radiation dose distributions for a 17-year-old female with an optic pathway glioma. Left column shows a photon intensity-modulated radiotherapy (IMRT) distribution with non-co-planar beams. The right column shows a pencil beam scanning proton beam therapy (PBT) distribution. Isodose line color legend is shown in the top-right inset. The axial, coronal, and sagittal views are shown in the top, middle, and bottom rows, respectively.

Figure 2

An 11-year-old female patient with intracranial germinoma. The intracranial RT target volumes are shown as follows: whole ventricular RT CTV (green) and 3 mm PTV geometric expansion (blue).

Figure 3

An example of the hippocampal−sparing whole brain radiotherapy plan. Grey shade represents the hippocampus, which is spared from a full dose of radiotherapy [154].