Validation of new transmission detector transmission factors for online dosimetry: an experimental study
Abstract Background The demand for dose verification during treatment has risen with the increasing use of intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) in modern radiation therapy. This study aims to validate the transmission factors of a new transmission...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2018-08-01
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| Series: | Radiation Oncology |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s13014-018-1106-y |
| _version_ | 1817988779451875328 |
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| author | So-Yeon Park Jong Min Park Jung-in Kim Sungyoung Lee Chang Heon Choi |
| author_facet | So-Yeon Park Jong Min Park Jung-in Kim Sungyoung Lee Chang Heon Choi |
| author_sort | So-Yeon Park |
| collection | DOAJ |
| description | Abstract Background The demand for dose verification during treatment has risen with the increasing use of intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) in modern radiation therapy. This study aims to validate the transmission factors of a new transmission detector, the Dolphin online monitoring system (IBA Dosimetry, Schwarzenbruck, Germany), for clinical use. Methods The transmission factors of the Dolphin detector were evaluated using 6 MV, 6 flattening filter free (FFF), 10 MV, and 10 FFF clinical beams from a TrueBeam STx linear accelerator system. Two-dimensional (2D) dose distributions were measured through portal dosimetry with and without Dolphin to derive the transmission factors. The measurements were performed using 10 IMRT and 10 VMAT treatment plans. The transmission factors were calculated using a non-negative least squares problem solver for the 2D dose matrix. Normalized plans were generated using the derived transmission factors. Patient-specific quality assurance with normalized plans was performed using portal dosimetry and an ArcCheck detector to verify the transmission factors. The gamma passing rates were calculated for the 2%/2 mm and 1%/1 mm criteria. Results The transmission factors for the 6 MV, 6 FFF, 10 MV, and 10 FFF beams, were 0.878, 0.824, 0.913, and 0.883, respectively. The average dose difference between the original plan without Dolphin and the normalized plan with Dolphin was less than 1.8% for all measurements. The mean passing rates of the gamma evaluation were 98.1 ± 2.1 and 82.9 ± 12.6 for the 2%/2 mm and 1%/1 mm criteria, respectively, for portal dosimetry of the original plan. In the case of the portal dosimetry of the normalized plan, the mean passing rates of the gamma evaluation were 97.2 ± 2.8 and 79.1 ± 14.8 for the 2%/2 mm and 1%/1 mm criteria, respectively. Conclusions The Dolphin detector can be used for online dosimetry when valid transmission factors are applied to the clinical plan. |
| first_indexed | 2024-04-14T00:38:42Z |
| format | Article |
| id | doaj.art-666b70062b904c89bf57b61b2ae91ef0 |
| institution | Directory Open Access Journal |
| issn | 1748-717X |
| language | English |
| last_indexed | 2024-04-14T00:38:42Z |
| publishDate | 2018-08-01 |
| publisher | BMC |
| record_format | Article |
| series | Radiation Oncology |
| spelling | doaj.art-666b70062b904c89bf57b61b2ae91ef02022-12-22T02:22:16ZengBMCRadiation Oncology1748-717X2018-08-011311910.1186/s13014-018-1106-yValidation of new transmission detector transmission factors for online dosimetry: an experimental studySo-Yeon Park0Jong Min Park1Jung-in Kim2Sungyoung Lee3Chang Heon Choi4Department of Radiation Oncology, Veterans Health Service Medical CenterInstitute of Radiation Medicine, Seoul National University Medical Research CenterInstitute of Radiation Medicine, Seoul National University Medical Research CenterBiomedical Research Institute, Seoul National University HospitalInstitute of Radiation Medicine, Seoul National University Medical Research CenterAbstract Background The demand for dose verification during treatment has risen with the increasing use of intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) in modern radiation therapy. This study aims to validate the transmission factors of a new transmission detector, the Dolphin online monitoring system (IBA Dosimetry, Schwarzenbruck, Germany), for clinical use. Methods The transmission factors of the Dolphin detector were evaluated using 6 MV, 6 flattening filter free (FFF), 10 MV, and 10 FFF clinical beams from a TrueBeam STx linear accelerator system. Two-dimensional (2D) dose distributions were measured through portal dosimetry with and without Dolphin to derive the transmission factors. The measurements were performed using 10 IMRT and 10 VMAT treatment plans. The transmission factors were calculated using a non-negative least squares problem solver for the 2D dose matrix. Normalized plans were generated using the derived transmission factors. Patient-specific quality assurance with normalized plans was performed using portal dosimetry and an ArcCheck detector to verify the transmission factors. The gamma passing rates were calculated for the 2%/2 mm and 1%/1 mm criteria. Results The transmission factors for the 6 MV, 6 FFF, 10 MV, and 10 FFF beams, were 0.878, 0.824, 0.913, and 0.883, respectively. The average dose difference between the original plan without Dolphin and the normalized plan with Dolphin was less than 1.8% for all measurements. The mean passing rates of the gamma evaluation were 98.1 ± 2.1 and 82.9 ± 12.6 for the 2%/2 mm and 1%/1 mm criteria, respectively, for portal dosimetry of the original plan. In the case of the portal dosimetry of the normalized plan, the mean passing rates of the gamma evaluation were 97.2 ± 2.8 and 79.1 ± 14.8 for the 2%/2 mm and 1%/1 mm criteria, respectively. Conclusions The Dolphin detector can be used for online dosimetry when valid transmission factors are applied to the clinical plan.http://link.springer.com/article/10.1186/s13014-018-1106-yTransmission detectorTransmission factorsPortal dosimetryOnline dosimetry |
| spellingShingle | So-Yeon Park Jong Min Park Jung-in Kim Sungyoung Lee Chang Heon Choi Validation of new transmission detector transmission factors for online dosimetry: an experimental study Radiation Oncology Transmission detector Transmission factors Portal dosimetry Online dosimetry |
| title | Validation of new transmission detector transmission factors for online dosimetry: an experimental study |
| title_full | Validation of new transmission detector transmission factors for online dosimetry: an experimental study |
| title_fullStr | Validation of new transmission detector transmission factors for online dosimetry: an experimental study |
| title_full_unstemmed | Validation of new transmission detector transmission factors for online dosimetry: an experimental study |
| title_short | Validation of new transmission detector transmission factors for online dosimetry: an experimental study |
| title_sort | validation of new transmission detector transmission factors for online dosimetry an experimental study |
| topic | Transmission detector Transmission factors Portal dosimetry Online dosimetry |
| url | http://link.springer.com/article/10.1186/s13014-018-1106-y |
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