First clinical experience with real-time portal imaging-based breath-hold monitoring in tangential breast radiotherapy
- Author(s)
- Vasina, EN; Kong, N; Greer, P; Baeza Ortega, J; Kron, T; Ludbrook, JJ; Thwaites, D; Lehmann, J;
- Journal Title
- Physics and Imaging in Radiation Oncology
- Publication Type
- Research article
- Abstract
- BACKGROUND AND PURPOSE: Real-time treatment monitoring with the electronic portal imaging device (EPID) can conceptually provide a more accurate assessment of the quality of deep inspiration breath-hold (DIBH) and patient movement during tangential breast radiotherapy (RT). A system was developed to measure two geometrical parameters, the lung depth (LD) and the irradiated width (named here skin distance, SD), along three user-selected lines in MV EPID images of breast tangents. The purpose of this study was to test the system during tangential breast RT with DIBH. MATERIALS AND METHODS: Measurements of LDs and SDs were carried out in real time. DIBH was guided with a commercial system using a marker block. Results from 17 patients were assessed. Mean midline LDs, <mLDs>, per tangent were compared to the planned mLDs; differences between the largest and smallest observed <mLDs> (<mSDs>) per tangent were calculated. RESULTS: For 56% (162/288) of the tangents tested, <mLDs> were outside the tolerance window. All but one patient had at least one fraction showing this behaviour. The largest difference found between an <mLD> and its planned mLD was -16.9 mm. The accuracy of patient positioning and the quality of marker-block-based DIBH guidance contributed to the differences. Fractions with patient position verification using a single EPID image taken before treatment showed a lower rate (34%), suggesting reassessment of setup procedures. CONCLUSIONS: Real-time treatment monitoring of the internal anatomy during DIBH delivery of tangential breast RT is feasible and useful. The new system requires no additional radiation for the patient.
- Keywords
- Dibh; Deep inspiration breath-hold; Epid; Electronic portal imaging device; Internal anatomy; Intra-fraction motion; Lung depth; Real-time monitoring; Tangential breast radiotherapy
- Department(s)
- Physical Sciences
- PubMed ID
- 36092771
- Publisher's Version
- https://doi.org/10.1016/j.phro.2022.08.002
- Open Access at Publisher's Site
https://doi.org/10.1016/j.phro.2022.08.002- Terms of Use/Rights Notice
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Creation Date: 2025-04-24 07:51:37
Last Modified: 2025-04-24 07:52:36