Usability and accuracy of high-resolution detectors for daily quality assurance for robotic radiosurgery
| Autor: | Björn Poppe, Oliver Blanck, Britta Loutfi-Krauss, Frank-André Siebert, Ulla Ramm, T. S. Stelljes, Marie-Christin Damme, Mark K. H. Chan |
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| Rok vydání: | 2017 |
| Předmět: |
robotic radiosurgery
Biomedical Engineering Standard deviation 030218 nuclear medicine & medical imaging law.invention 03 medical and health sciences 0302 clinical medicine law Cyberknife cyberknife Simulation Mathematics automatic quality assurance gafchromic film business.industry Detector Usability Gold standard (test) Nonius 030220 oncology & carcinogenesis high-resolution arrays Medicine business Quality assurance Sensitivity (electronics) |
| Zdroj: | Current Directions in Biomedical Engineering, Vol 3, Iss 2, Pp 277-280 (2017) |
| ISSN: | 2364-5504 |
| Popis: | For daily CyberKnife QA a Winston-Lutz-Test (Automated-Quality-Assurance, AQA) is used to determine sub-millimeter deviations in beam delivery accuracy. This test is performed using gafchromic film, an extensive and user-dependent method requiring the use of disposables. We therefore analyzed the usability and accuracy of high-resolution detector arrays. We analyzed a liquid-filled ionization-chamber array (Octavius 1000SRS, PTW, Germany), which has a central resolution of 2.5mm. To test sufficient sensitivity, beam profiles with robot shifts of 0.1mm along the arrays' axes were measured. The detected deviation between the shifted and central profile were compared to the real robot's position. We then compared the results to the SRS-Profiler (SunNuclear, USA) with 4.0mm resolution and to the Nonius (QUART, Germany), a single-line diode detector with 2.8mm resolution. Finally, AQA variance and usability were analyzed performing a number of AQA tests over time, which required the use of specially designed fixtures for each array, and the results were compared to film. Concerning sensitivity, the 1000SRS detected the beam profile shifts with a maximum difference of 0.11mm (mean deviation = 0.03mm) compared to the actual robot shift. The Nonius and SRS-Profiler showed differences of up to 0.15mm and 0.69mm with mean deviation of 0.05mm and 0.18mm, respectively. Analyzing the variation of AQA results over time, the 1000SRS showed a comparable standard deviation to film (0.26mm vs. 0.18mm). The SRS-Profiler and the Nonius showed a standard deviation of 0.16mm and 0.24mm, respectively. The 1000SRS seems to provide equivalent accuracy and sensitivity to the gold standard film when performing daily AQA tests. Compared to other detectors in our study the sensitivity as well as the accuracy of the 1000SRS appears to be superior and more user-friendly. Furthermore, no significant modification of the standard AQA procedure is required when introducing 1000SRS for CyberKnife AQA. |
| Databáze: | OpenAIRE |
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