Measurement of total scatter factor for stereotactic cones with plastic scintillation detector
Advanced radiotherapy modalities such as stereotactic radiosurgery (SRS) and image-guided radiotherapy may employ very small beam apertures for accurate localized high dose to target. Accurate measurement of small radiation fields is a well-known challenge for many dosimeters. The purpose of this st...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wolters Kluwer Medknow Publications
2017-01-01
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| Series: | Journal of Medical Physics |
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| Online Access: | http://www.jmp.org.in/article.asp?issn=0971-6203;year=2017;volume=42;issue=1;spage=9;epage=13;aulast=Chaudhari |
| _version_ | 1828520923120009216 |
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| author | Suresh H Chaudhari Rishabh Dobhal Rajesh A Kinhikar Sudarshan S Kadam Deepak D Deshpande |
| author_facet | Suresh H Chaudhari Rishabh Dobhal Rajesh A Kinhikar Sudarshan S Kadam Deepak D Deshpande |
| author_sort | Suresh H Chaudhari |
| collection | DOAJ |
| description | Advanced radiotherapy modalities such as stereotactic radiosurgery (SRS) and image-guided radiotherapy may employ very small beam apertures for accurate localized high dose to target. Accurate measurement of small radiation fields is a well-known challenge for many dosimeters. The purpose of this study was to measure total scatter factors for stereotactic cones with plastic scintillation detector and its comparison against diode detector and theoretical estimates. Measurements were performed on Novalis Tx™ linear accelerator for 6MV SRS beam with stereotactic cones of diameter 6 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm. The advantage of plastic scintillator detector is in its energy dependence. The total scatter factor was measured in water at the depth of dose maximum. Total scatter factor with plastic scintillation detector was determined by normalizing the readings to field size of 10 cm × 10 cm. To overcome energy dependence of diode detector for the determination of scatter factor with diode detector, daisy chaining method was used. The plastic scintillator detector was calibrated against the ionization chamber, and the reproducibility in the measured doses was found to be within ± 1%. Total scatter factor measured with plastic scintillation detector was 0.728 ± 0.3, 0.783 ± 0.05, 0.866 ± 0.55, 0.885 ± 0.5, and 0.910 ± 0.06 for cone sizes of 6 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm, respectively. Total scatter factor measured with diode detector was 0.733 ± 0.03, 0.782 ± 0.02, 0.834 ± 0.07, 0.854 ± 0.02, and 0.872 ± 0.02 for cone sizes of 6 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm, respectively. The variation in the measurement of total scatter factor with published Monte Carlo data was found to be −1.3%, 1.9%, −0.4%, and 0.4% for cone sizes of 7.5 mm, 10 mm, 12.5 mm, and 15 mm, respectively. We conclude that total scatter factor measurements for stereotactic cones can be adequately carried out with a plastic scintillation detector. Our results show a high level of consistency within our data and compared well with published data. |
| first_indexed | 2024-12-11T19:39:34Z |
| format | Article |
| id | doaj.art-628a74cdd2e14136ab1572421daf78a7 |
| institution | Directory Open Access Journal |
| issn | 0971-6203 1998-3913 |
| language | English |
| last_indexed | 2024-12-11T19:39:34Z |
| publishDate | 2017-01-01 |
| publisher | Wolters Kluwer Medknow Publications |
| record_format | Article |
| series | Journal of Medical Physics |
| spelling | doaj.art-628a74cdd2e14136ab1572421daf78a72022-12-22T00:53:03ZengWolters Kluwer Medknow PublicationsJournal of Medical Physics0971-62031998-39132017-01-0142191310.4103/jmp.JMP_114_16Measurement of total scatter factor for stereotactic cones with plastic scintillation detectorSuresh H ChaudhariRishabh DobhalRajesh A KinhikarSudarshan S KadamDeepak D DeshpandeAdvanced radiotherapy modalities such as stereotactic radiosurgery (SRS) and image-guided radiotherapy may employ very small beam apertures for accurate localized high dose to target. Accurate measurement of small radiation fields is a well-known challenge for many dosimeters. The purpose of this study was to measure total scatter factors for stereotactic cones with plastic scintillation detector and its comparison against diode detector and theoretical estimates. Measurements were performed on Novalis Tx™ linear accelerator for 6MV SRS beam with stereotactic cones of diameter 6 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm. The advantage of plastic scintillator detector is in its energy dependence. The total scatter factor was measured in water at the depth of dose maximum. Total scatter factor with plastic scintillation detector was determined by normalizing the readings to field size of 10 cm × 10 cm. To overcome energy dependence of diode detector for the determination of scatter factor with diode detector, daisy chaining method was used. The plastic scintillator detector was calibrated against the ionization chamber, and the reproducibility in the measured doses was found to be within ± 1%. Total scatter factor measured with plastic scintillation detector was 0.728 ± 0.3, 0.783 ± 0.05, 0.866 ± 0.55, 0.885 ± 0.5, and 0.910 ± 0.06 for cone sizes of 6 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm, respectively. Total scatter factor measured with diode detector was 0.733 ± 0.03, 0.782 ± 0.02, 0.834 ± 0.07, 0.854 ± 0.02, and 0.872 ± 0.02 for cone sizes of 6 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm, respectively. The variation in the measurement of total scatter factor with published Monte Carlo data was found to be −1.3%, 1.9%, −0.4%, and 0.4% for cone sizes of 7.5 mm, 10 mm, 12.5 mm, and 15 mm, respectively. We conclude that total scatter factor measurements for stereotactic cones can be adequately carried out with a plastic scintillation detector. Our results show a high level of consistency within our data and compared well with published data.http://www.jmp.org.in/article.asp?issn=0971-6203;year=2017;volume=42;issue=1;spage=9;epage=13;aulast=ChaudhariPlastic scintillatorsmall field dosimetrytotal scatter factor |
| spellingShingle | Suresh H Chaudhari Rishabh Dobhal Rajesh A Kinhikar Sudarshan S Kadam Deepak D Deshpande Measurement of total scatter factor for stereotactic cones with plastic scintillation detector Journal of Medical Physics Plastic scintillator small field dosimetry total scatter factor |
| title | Measurement of total scatter factor for stereotactic cones with plastic scintillation detector |
| title_full | Measurement of total scatter factor for stereotactic cones with plastic scintillation detector |
| title_fullStr | Measurement of total scatter factor for stereotactic cones with plastic scintillation detector |
| title_full_unstemmed | Measurement of total scatter factor for stereotactic cones with plastic scintillation detector |
| title_short | Measurement of total scatter factor for stereotactic cones with plastic scintillation detector |
| title_sort | measurement of total scatter factor for stereotactic cones with plastic scintillation detector |
| topic | Plastic scintillator small field dosimetry total scatter factor |
| url | http://www.jmp.org.in/article.asp?issn=0971-6203;year=2017;volume=42;issue=1;spage=9;epage=13;aulast=Chaudhari |
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