Clinical utility of Gafchromic film in an MRI-guided linear accelerator
Abstract Background The purpose of this study is to comprehensively evaluate the suitability of Gafchromic EBT3 and EBT-XD film for dosimetric quality assurance in 0.35 T MR-guided radiotherapy. Methods A 0.35 T magnetic field strength was utilized to evaluate magnetic field effects on EBT3 and EBT-...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2021-06-01
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| Series: | Radiation Oncology |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s13014-021-01844-z |
| _version_ | 1818462025731276800 |
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| author | Ilma Xhaferllari Joshua P. Kim Ruchira Liyanage Chang Liu Dongsu Du Anthony Doemer Indrin J. Chetty Ning Wen |
| author_facet | Ilma Xhaferllari Joshua P. Kim Ruchira Liyanage Chang Liu Dongsu Du Anthony Doemer Indrin J. Chetty Ning Wen |
| author_sort | Ilma Xhaferllari |
| collection | DOAJ |
| description | Abstract Background The purpose of this study is to comprehensively evaluate the suitability of Gafchromic EBT3 and EBT-XD film for dosimetric quality assurance in 0.35 T MR-guided radiotherapy. Methods A 0.35 T magnetic field strength was utilized to evaluate magnetic field effects on EBT3 and EBT-XD Gafchromic films by studying the effect of film exposure time within the magnetic field using two timing sequences and film not exposed to MR, the effect of magnetic field exposure on the crystalline structure of the film, and the effect of orientation of the film with respect to the bore within the magnetic field. The orientation of the monomer crystal was qualitatively evaluated using scanning electron microscopy (SEM) compared to unirradiated film. Additionally, dosimetric impact was evaluated through measurements of a series of open field irradiations (0.83 × 0.83-cm2 to 19.92 × 19.92-cm2) and patient specific quality assurance measurements. Open fields were compared to planned dose and an independent dosimeter. Film dosimetry was applied to twenty conventional and twenty stereotactic body radiotherapy (SBRT) patient specific quality assurance cases. Results No visual changes in crystal orientation were observed in any evaluated SEM images nor were any optical density differences observed between films irradiated inside or outside the magnetic field for both EBT3 and EBT-XD film. At small field sizes, the average difference along dose profiles measured in film compared to the same points measured using an independent dosimeter and to predicted treatment planning system values was 1.23% and 1.56%, respectively. For large field sizes, the average differences were 1.91% and 1.21%, respectively. In open field tests, the average gamma pass rates were 99.8% and 97.2%, for 3%/3 mm and 3%/1 mm, respectively. The median (interquartile range) 3%/3 mm gamma pass rates in conventional QA cases were 98.4% (96.3 to 99.2%), and 3%/1 mm in SBRT QA cases were 95.8% (95.0 to 97.3%). Conclusions MR exposure at 0.35 T had negligible effects on EBT3 and EBT-XD Gafchromic film. Dosimetric film results were comparable to planned dose, ion chamber and diode measurements. |
| first_indexed | 2024-12-14T23:55:29Z |
| format | Article |
| id | doaj.art-f3886fb304ba4b688859ec76c3f40bc2 |
| institution | Directory Open Access Journal |
| issn | 1748-717X |
| language | English |
| last_indexed | 2024-12-14T23:55:29Z |
| publishDate | 2021-06-01 |
| publisher | BMC |
| record_format | Article |
| series | Radiation Oncology |
| spelling | doaj.art-f3886fb304ba4b688859ec76c3f40bc22022-12-21T22:43:08ZengBMCRadiation Oncology1748-717X2021-06-0116111210.1186/s13014-021-01844-zClinical utility of Gafchromic film in an MRI-guided linear acceleratorIlma Xhaferllari0Joshua P. Kim1Ruchira Liyanage2Chang Liu3Dongsu Du4Anthony Doemer5Indrin J. Chetty6Ning Wen7Department of Radiation Oncology, Beaumont HealthDepartment of Radiation Oncology, Henry Ford Health SystemDepartment of Chemical Engineering and Material Science, Wayne State UniversityDepartment of Radiation Oncology, Henry Ford Health SystemDepartment of Radiation Oncology, Henry Ford Health SystemDepartment of Radiation Oncology, Henry Ford Health SystemDepartment of Radiation Oncology, Henry Ford Health SystemDepartment of Radiation Oncology, Henry Ford Health SystemAbstract Background The purpose of this study is to comprehensively evaluate the suitability of Gafchromic EBT3 and EBT-XD film for dosimetric quality assurance in 0.35 T MR-guided radiotherapy. Methods A 0.35 T magnetic field strength was utilized to evaluate magnetic field effects on EBT3 and EBT-XD Gafchromic films by studying the effect of film exposure time within the magnetic field using two timing sequences and film not exposed to MR, the effect of magnetic field exposure on the crystalline structure of the film, and the effect of orientation of the film with respect to the bore within the magnetic field. The orientation of the monomer crystal was qualitatively evaluated using scanning electron microscopy (SEM) compared to unirradiated film. Additionally, dosimetric impact was evaluated through measurements of a series of open field irradiations (0.83 × 0.83-cm2 to 19.92 × 19.92-cm2) and patient specific quality assurance measurements. Open fields were compared to planned dose and an independent dosimeter. Film dosimetry was applied to twenty conventional and twenty stereotactic body radiotherapy (SBRT) patient specific quality assurance cases. Results No visual changes in crystal orientation were observed in any evaluated SEM images nor were any optical density differences observed between films irradiated inside or outside the magnetic field for both EBT3 and EBT-XD film. At small field sizes, the average difference along dose profiles measured in film compared to the same points measured using an independent dosimeter and to predicted treatment planning system values was 1.23% and 1.56%, respectively. For large field sizes, the average differences were 1.91% and 1.21%, respectively. In open field tests, the average gamma pass rates were 99.8% and 97.2%, for 3%/3 mm and 3%/1 mm, respectively. The median (interquartile range) 3%/3 mm gamma pass rates in conventional QA cases were 98.4% (96.3 to 99.2%), and 3%/1 mm in SBRT QA cases were 95.8% (95.0 to 97.3%). Conclusions MR exposure at 0.35 T had negligible effects on EBT3 and EBT-XD Gafchromic film. Dosimetric film results were comparable to planned dose, ion chamber and diode measurements.https://doi.org/10.1186/s13014-021-01844-zMRI-guided linacGafchromic filmQuality assurance |
| spellingShingle | Ilma Xhaferllari Joshua P. Kim Ruchira Liyanage Chang Liu Dongsu Du Anthony Doemer Indrin J. Chetty Ning Wen Clinical utility of Gafchromic film in an MRI-guided linear accelerator Radiation Oncology MRI-guided linac Gafchromic film Quality assurance |
| title | Clinical utility of Gafchromic film in an MRI-guided linear accelerator |
| title_full | Clinical utility of Gafchromic film in an MRI-guided linear accelerator |
| title_fullStr | Clinical utility of Gafchromic film in an MRI-guided linear accelerator |
| title_full_unstemmed | Clinical utility of Gafchromic film in an MRI-guided linear accelerator |
| title_short | Clinical utility of Gafchromic film in an MRI-guided linear accelerator |
| title_sort | clinical utility of gafchromic film in an mri guided linear accelerator |
| topic | MRI-guided linac Gafchromic film Quality assurance |
| url | https://doi.org/10.1186/s13014-021-01844-z |
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