Speaker
Description
Accurate in-vivo dose monitoring is increasingly important in radiotherapy to comply with stringent dose delivery guidelines. Electronic Portal Imaging Devices (EPIDs), routinely used for patient positioning, offer the potential for real-time treatment monitoring. However, EPID images are only indirectly related to patient dose, and their use for error detection is challenging. In this study, an in-house developed DL model was used to transform raw EPID images into water equivalent portal dose images. Particularly, we assessed the feasibility of using these DL-generated portal dose images for application in a real time error detection alert system in phantom experiments, performed at the Careggi university hospital (Firenze, Italy).
Different phantoms were irradiated under reference conditions and with intentionally introduced treatment errors, including deviations in monitoring units (MU) and phantom shifts. EPID images were converted to portal dose images using the DL model, and several comparison metrics were evaluated, including gamma-index analysis and relative mean absolute dose difference (reMADD). The results demonstrate that MU errors can be reliably detected using a combination of metrics. Gamma passing rates decreased with increasing MU errors, while reMADD provided consistent sensitivity across different phantoms and field sizes. Setup errors were more challenging to detect, particularly for narrow fields, with reMADD showing slightly better sensitivity than gamma analysis.
Overall, the proposed DL-based portal dose comparison framework is appropriate for application in a real time alert system for detection of treatment errors. Future work will focus on extending the approach to clinical patient data.
| Minioral | Yes |
|---|---|
| IEEE Member | No |
| Are you a student? | No |