Evaluating the Impact of In Vivo EPID Dosimetry on Intensity-Modulated Radiation Therapy Treatment Delivery Workflow: A Stakeholder Perspective

Introduction In vivo electronic portal imaging device (EPID) dosimetry is an advanced imaging technique that can obtain patient-specific dose data for quality assurance purposes. However, clinical integration of this technique remains a challenge. This study evaluates the impact of implementing an in vivo EPID technique into the treatment delivery workflow for head and neck cancer (HNC) patients in a large cancer centre setting. Materials/Methods Intensity-modulated radiation therapy treatment delivery was simulated on a phantom for 10 HNC cases with and without in vivo EPID dosimetry. Investigators performed the EPID technique by using a preliminary protocol written by medical physicists. Process maps were created to illustrate changes in treatment delivery workflow. Results Treatment delivery times increased by an average of 2.34 minutes (P = .0006) when the EPID technique was used. Factors that increased treatment times included the time for storing captured EPID data, adjustment of the imaging panel position as a function of field size, and an inability to use automatic field sequencing when acquiring images. Conclusions The involvement of stakeholders in protocol development allows for the identification of usability issues and staff training needs. Findings from this study have identified limitations of the in vivo EPID technique that may negatively impact treatment delivery workflow. Efficiencies within in vivo EPID dosimetry systems can be improved by enabling automatic field sequencing with automatic image-saving capabilities.