RefleXion X1 Treatment Planning Feasibility Study for Craniospinal Irradiation (CSI)

Le résumé fourni par la source

Abstract Objective: The first clinical biology-guided radiation therapy system, RefleXion X1, was commissioned for clinical use at our institution. This study evaluates the X1 treatment planning feasibility of complex craniospinal targets for pediatric medulloblastoma patients and compares plan quality to multi-isocenter linac-based Volumetric Modulated Arc Therapy (VMAT) plans. Methods: Five pediatric patients treated with multi-isocenter VMAT craniospinal irradiation (CSI) were selected for this retrospective study. All planning target volumes (PTVs) had a craniocaudal length < 50 cm and received 36 Gy in 20 fractions. The target volumes and organs-at-risk (OARs) used for VMAT plans were utilized to generate plans using RefleXion X1. PTV D2%, OARs Dmean and Dmax, and treatment times were collected for analysis. A paired-sample t-test was performed to detect significance at P < 0.05. Results: All 5 X1 CSI plans were successfully generated and deemed clinically acceptable for treatment. PTV D2% was found to be greater for X1 compared with VMAT plans (P = .08). For the X1 plans, the Dmean to the bowel, cochleas, heart, kidneys, lungs, and oral cavity was not found to be statistically significant (P > .05) compared with VMAT plans. The average treatment beam-on time for X1 plans was 16.7 minutes vs 3.6 minutes for VMAT plans (P < .01). However, the RefleXion X1 platform enables one isocenter treatment and 90-cm-long kilovoltage CT scan, which has the potential to reduce the setup/imaging time, and thus the total treatment time compared with multi-isocenter linac-based VMAT, where the total treatment time of up to 43.5 minutes was observed. Conclusion: Apart from a greater maximum dose to PTV, X1 plans showed comparable dosimetry to multi-isocenter VMAT plans. Although the average beam-on time with X1 was longer, there is a potential for a more streamlined setup and IGRT using a single isocenter plan.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.