Radiation Therapy for Pediatric Brain Tumors using Robotic Radiation Delivery System and Intensity Modulated Proton Therapy

Abstract. Purpose This study recruited two centers with expertise in treating pediatric brain tumors with robotic radiation delivery system photon therapy and proton therapy, respectively, to study the plan quality and the dose deposition characteristics of robotic radiation delivery system photon and intensity modulated proton therapy (IMPT) plans. Methods and Materials A total of 18 patients clinically treated with robotic radiation delivery system were planned with intensity-modulated-proton-therapy (IMPT). Cases were planned per the standard of care of each institution but, respected the same planning objectives. The comparison was performed in three aspects: the plan quality, dose fall-off characteristics around target volume and the volume of high, intermediate, and low dose bath. Results All robotic radiation delivery system and IMPT plans meet the planning objectives. However, IMPT significantly reduces the maximum dose of the OARs away from the planning target volume (PTV) such as cochlea and eye (P Conclusion In general, robotic radiation delivery system plans exhibit reduced high dose exposure to normal tissue while IMPT plans have considerably smaller volumes of low dose exposure with differences in medium range dose bath increasingly favoring protons as tumor size increases.