Assessing Surface Guided Radiation Therapy Benefits for Paediatric Cancer Patients: Dosimetric Implications of Intrafractional Motion - An Institutional Review

<i>Introduction/Background</i>: SGRT, a real-time imaging technique, offers continuous monitoring and motion control during <i>treatment</i>. The investigation aims to assess potential dosimetric alterations in target coverage due to intrafractional motion, considering its impact on patient safety and treatment efficiency. <i>Materials and Methods</i>: A retrospective chart review was conducted to assess intrafractional shifts in 18 paediatric cancer patients. Patient setup employed SGRT using AlignRT (Vision RT Ltd., UK), and the PTV was aligned with CBCT. The study introduced induced shifts of 3 mm, 5 mm, and 7 mm during treatment delivery, assessing their impact on portal dosimetry results for both treatment fields. The gamma index criteria (3%, 3 mm) were employed to evaluate dosimetric accuracy. <i>Results</i>: A total of 18 patients were included, and induced shifts were analyzed for their impact on the planned gamma index values. Significant differences were observed between the Planned Gamma Index and induced shifts of 3 mm, 5 mm, and 7 mm for both treatment fields, highlighting the dosimetric implications of intrafractional motion in paediatric cases. <i>Conclusion</i>: Surface Guided Radiation Therapy (SGRT) is concluded to offer a comprehensive array of benefits for paediatric cases. The dosimetric implications of induced shifts underscore the importance of SGRT in ensuring accurate and safe treatment for paediatric cancer patients.