Does fluence smoothing reduce the complexity of the intensity-modulated radiation therapy treatment plan? A dosimetric analysis
Background: Intensity-modulated radiation therapy (IMRT) may have too many peaks and valleys, making the treatment plan undeliverable. When there are too many fluency differences between adjacent pixels in the X or Y directions, the X and Y smoothing factors are utilized as weighting factors to pena...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Wolters Kluwer Medknow Publications
2022-01-01
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| Series: | Journal of Medical Physics |
| Subjects: | |
| Online Access: | http://www.jmp.org.in/article.asp?issn=0971-6203;year=2022;volume=47;issue=4;spage=336;epage=343;aulast=Saroj |
| _version_ | 1797904818202738688 |
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| author | Dinesh Kumar Saroj Suresh Yadav Neetu Paliwal |
| author_facet | Dinesh Kumar Saroj Suresh Yadav Neetu Paliwal |
| author_sort | Dinesh Kumar Saroj |
| collection | DOAJ |
| description | Background: Intensity-modulated radiation therapy (IMRT) may have too many peaks and valleys, making the treatment plan undeliverable. When there are too many fluency differences between adjacent pixels in the X or Y directions, the X and Y smoothing factors are utilized as weighting factors to penalize this behavior. Generally, a high degree of complexity is accompanied by many monitor units (MUs), large number of segments, small sized segments, and complex segment shapes. The degree of plan delivery uncertainty can all increase with a higher detailed fluence map. Aim: This study aims to evaluate the dosimetric effects of various smoothing levels on the planning target volume (PTV) and organs at risk (OARs) for cervix cancer. Materials and Methods: IMRT treatment plans were re-optimized by combining several values of the X and Y penalty between 0 and 100. The dose–volume histogram assessed various dosimetric indicators for PTV and OARs. Additionally, gamma passing rates were evaluated and noted as an indicator of the complex treatment plan. Results: At X = 60, Y = 60 fluence map penalty, the conformity index (CI) value reached its highest value of 0.996 ± 0.004. At X = 0, Y = 0, the homogeneity index (HI) was determined to have a maximum value of 0.0628 ± 0.0235. The highest and lowest MU values were 2424.30 ± 471.12 and 1087.80 ± 91.57, respectively, with X = 0, Y = 0 and X = 100, Y = 100. At X = 100, Y = 100, the gamma passing rate reaches its highest value of 99.28% ± 0.44% and minimum value of 85.93% ± 3.87% at X = 0, Y = 0. Conclusion: The CI and HI values showed no discernible fluctuation, and the OAR doses were barely affected as smoothing was increased. When the smoothing factor was raised, the number of MUs sharply dropped, and a decrease in the number of segments and higher gamma passing rates were also seen. |
| first_indexed | 2024-04-10T09:54:59Z |
| format | Article |
| id | doaj.art-0aa541d4540b493b9c39a615563967dc |
| institution | Directory Open Access Journal |
| issn | 0971-6203 1998-3913 |
| language | English |
| last_indexed | 2024-04-10T09:54:59Z |
| publishDate | 2022-01-01 |
| publisher | Wolters Kluwer Medknow Publications |
| record_format | Article |
| series | Journal of Medical Physics |
| spelling | doaj.art-0aa541d4540b493b9c39a615563967dc2023-02-16T12:33:57ZengWolters Kluwer Medknow PublicationsJournal of Medical Physics0971-62031998-39132022-01-0147433634310.4103/jmp.jmp_81_22Does fluence smoothing reduce the complexity of the intensity-modulated radiation therapy treatment plan? A dosimetric analysisDinesh Kumar SarojSuresh YadavNeetu PaliwalBackground: Intensity-modulated radiation therapy (IMRT) may have too many peaks and valleys, making the treatment plan undeliverable. When there are too many fluency differences between adjacent pixels in the X or Y directions, the X and Y smoothing factors are utilized as weighting factors to penalize this behavior. Generally, a high degree of complexity is accompanied by many monitor units (MUs), large number of segments, small sized segments, and complex segment shapes. The degree of plan delivery uncertainty can all increase with a higher detailed fluence map. Aim: This study aims to evaluate the dosimetric effects of various smoothing levels on the planning target volume (PTV) and organs at risk (OARs) for cervix cancer. Materials and Methods: IMRT treatment plans were re-optimized by combining several values of the X and Y penalty between 0 and 100. The dose–volume histogram assessed various dosimetric indicators for PTV and OARs. Additionally, gamma passing rates were evaluated and noted as an indicator of the complex treatment plan. Results: At X = 60, Y = 60 fluence map penalty, the conformity index (CI) value reached its highest value of 0.996 ± 0.004. At X = 0, Y = 0, the homogeneity index (HI) was determined to have a maximum value of 0.0628 ± 0.0235. The highest and lowest MU values were 2424.30 ± 471.12 and 1087.80 ± 91.57, respectively, with X = 0, Y = 0 and X = 100, Y = 100. At X = 100, Y = 100, the gamma passing rate reaches its highest value of 99.28% ± 0.44% and minimum value of 85.93% ± 3.87% at X = 0, Y = 0. Conclusion: The CI and HI values showed no discernible fluctuation, and the OAR doses were barely affected as smoothing was increased. When the smoothing factor was raised, the number of MUs sharply dropped, and a decrease in the number of segments and higher gamma passing rates were also seen.http://www.jmp.org.in/article.asp?issn=0971-6203;year=2022;volume=47;issue=4;spage=336;epage=343;aulast=Sarojcomplexityfluencegamma passing ratemonitor unitsradiotherapy |
| spellingShingle | Dinesh Kumar Saroj Suresh Yadav Neetu Paliwal Does fluence smoothing reduce the complexity of the intensity-modulated radiation therapy treatment plan? A dosimetric analysis Journal of Medical Physics complexity fluence gamma passing rate monitor units radiotherapy |
| title | Does fluence smoothing reduce the complexity of the intensity-modulated radiation therapy treatment plan? A dosimetric analysis |
| title_full | Does fluence smoothing reduce the complexity of the intensity-modulated radiation therapy treatment plan? A dosimetric analysis |
| title_fullStr | Does fluence smoothing reduce the complexity of the intensity-modulated radiation therapy treatment plan? A dosimetric analysis |
| title_full_unstemmed | Does fluence smoothing reduce the complexity of the intensity-modulated radiation therapy treatment plan? A dosimetric analysis |
| title_short | Does fluence smoothing reduce the complexity of the intensity-modulated radiation therapy treatment plan? A dosimetric analysis |
| title_sort | does fluence smoothing reduce the complexity of the intensity modulated radiation therapy treatment plan a dosimetric analysis |
| topic | complexity fluence gamma passing rate monitor units radiotherapy |
| url | http://www.jmp.org.in/article.asp?issn=0971-6203;year=2022;volume=47;issue=4;spage=336;epage=343;aulast=Saroj |
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