Dosimetric analysis and acute toxicity in cranio-spinal irradiation using helical tomotherapy: Experience from a tertiary cancer center

Purpose: The purpose of this study was to assess the feasibility and efficacy of helical intensity-modulated radiation therapy for cranio-spinal irradiation (CSI) on tomotherapy, aiming to enhance target coverage while minimizing radiation dose to nearby organs at risk (OARs) and to assess acute toxicities. Materials and Methods: It was a prospective observational single-arm study, 24 patients meeting inclusion criteria were enrolled, with most common histology being medulloblastoma. Planning was executed using the accuracy precision system, adhering to European Society of Pediatric Oncology guidelines for contouring. Dosimetric analysis encompassing target coverage, conformity, homogeneity, and OAR sparing was performed. Acute side effects were assessed using CTCAE 4.0. Results: Tomotherapy showed acceptable target coverage and spared OARs, although some patients exceeded QUANTEC dose limits due to factors such as target volume, prescribed dose, and proximity to OARs. Hematological and skin-related adverse events were observed, mostly mild to moderate. These toxicities were generally acceptable. Conclusion: Tomotherapy demonstrated effectiveness in target coverage and OAR sparing, careful consideration of dose limits and field width is crucial to minimize toxicity risks. These findings contribute to the understanding of the feasibility and safety profile of tomotherapy in CSI. Larger cohorts and extended follow-up periods are necessary to evaluate late toxicities comprehensively.