Adamson, Susan2024-03-142024-03-142024-03-13https://eresearch.qmu.ac.uk/handle/20.500.12289/13696​Background and purpose ​Prostate cancer is one of the most prevalent malignancies within oncology cases. Intrafraction motion is an important consideration in the clinical delivery of radiotherapy and indeed, long-term outcome and toxicity for patients. The purpose of this retrospective clinical audit was to review the efficacy of the RayPilot® real time motion management system and the impact that this has on planning target margins in prostate stereotactic body radiotherapy to assess if the RayPilot® system could be used clinically to allow for further dose escalation and fractionation reduction. ​Materials and methods ​Intrafraction motion was measured and recorded using the RayPilot® real time motion management system in seven patients. The RayPilot® system collated intrafraction data thirty times per second during treatment delivery for each patient. The collected data was then used to replan the patient in the Eclipse treatment planning software using reduced planning target margins to assess if this was a feasible method of dose escalation by reducing treatment fractionation. ​Results ​The RayPilot® recorded data resulted in 54175 intrafraction motion measurements in total. Mean displacement (following removal of outliers >0.3cm) was 0.1cm (SD± 0.1cm), 0.1cm (SD± 0.1cm) and 0.1cm (SD± 0.1cm) in the lateral, longitudinal and vertical directions respectively. The Van Herk Margin recipe was used to calculate the required clinical margins using the intrafraction motion data resulting in lateral, longitudinal and vertical margins of 0.7cm, 0.7cm and 0.7cm respectively. These margins allowed for dose escalation of 2400cGy in three fractions with no detrimental effects or increase in patient toxicity using dose volume histogram analysis. ​Conclusion ​RayPilot® is an efficient method of monitoring and recording prostate intrafraction motion and allowed for a reduction in target volume margins resulting in dose escalation in prostate stereotactic body radiotherapy. However, further analysis and research must be carried out to assess the feasibility of it being used as a stand-alone monitoring modality.Thesis