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Error detection during VMAT delivery using EPID-based 3D transit dosimetry
| Content Provider | Scilit |
|---|---|
| Author | Mijnheer, B. Jomehzadeh, A. González, P. Olaciregui-Ruiz, I. Rozendaal, R. Shokrani, P. Spreeuw, H. Tielenburg, R. Mans, A. |
| Copyright Year | 2018 |
| Description | Journal: Physica Medica Purpose To investigate the effectiveness of an EPID-based 3D transit dosimetry system in detecting deliberately introduced errors during VMAT delivery. Methods An Alderson phantom was irradiated using four VMAT treatment plans (one prostate, two head-and-neck and one lung case) in which delivery, thickness and setup errors were introduced. EPID measurements were performed to reconstruct 3D dose distributions of "error" plans, which were compared with "no-error" plans using the mean gamma $(γ_{mean}$), near-maximum gamma $(γ_{1%}$) and the difference in isocenter dose $(ΔD_{isoc}$) as metrics. Results Out of a total of 42 serious errors, the number of errors detected was 33 (79%), and 27 out of 30 (90%) if setup errors are not included. The system was able to pick up errors of 5 mm movement of a leaf bank, a wrong collimator rotation angle and a wrong photon beam energy. A change in phantom thickness of 1 cm was detected for all cases, while only for the head-and-neck plans a 2 cm horizontal and vertical shift of the phantom were alerted. A single leaf error of 5 mm could be detected for the lung plan only. Conclusion Although performed for a limited number of cases and error types, this study shows that EPID-based 3D transit dosimetry is able to detect a number of serious errors in dose delivery, leaf bank position and patient thickness during VMAT delivery. Errors in patient setup and single leaf position can only be detected in specific cases. |
| Related Links | http://www.physicamedica.com/article/S1120179718312912/pdf |
| Ending Page | 145 |
| Page Count | 9 |
| Starting Page | 137 |
| ISSN | 11201797 |
| DOI | 10.1016/j.ejmp.2018.10.005 |
| Journal | Physica Medica |
| Volume Number | 54 |
| Language | English |
| Publisher | Elsevier BV |
| Publisher Date | 2018-10-01 |
| Access Restriction | Open |
| Subject Keyword | Journal: Physica Medica Radiology, Nuclear Medicine and Imaging Epid Dosimetry Error Detection Quality Assurance |
| Content Type | Text |
| Resource Type | Article |
| Subject | Radiology, Nuclear Medicine and Imaging Physics and Astronomy Biophysics |
