Proton Craniospinal Radiation Therapy: Rationale and Clinical Evidence

Abstract

Purpose: To review the existing evidence that supports the use of proton craniospinal irradiation (p-CSI) in pediatric patients. Materials and Methods: A literature review was performed exploring the current evidence for the use of p-CSI. The theoretical advantages based on dosimetry and predictive toxicity models are described. The technical advances in p-CSI delivery are reviewed. The existing and emerging clinical data, including cost-benefit analyses are evaluated. Results: The theoretical advantages based on dosimetry comparisons to x-ray–based CSI consistently support the potential benefit of p-CSI. Similarly, the predictive models suggest a reduction in the risks of organ toxicity and radiation-associated second malignancies. The early clinical data that are emerging confirm similar tumor control rates with some support of reduction in early measurable toxicities. Several studies support an overall cost-benefit advantage when the potential reduction in side effects with p-CSI is considered. Conclusions: Based on the theoretical and early clinical outcomes, p-CSI appears to provide equal tumor control with potentially reduced risk of side effects when compared with data. Ongoing efforts will continue to evaluate these advantages.