Influence of photon energy on the quality of prostate intensity modulated radiation therapy plans based on analysis of physical indices
The goal of the present study was to study the effects of low- and high-energy intensity-modulated photon beams on the planning of target volume and the critical organs in cases of localized prostate tumors in a cohort of 8 patients. To ensure that the difference between the plans is due to energy a...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Wolters Kluwer Medknow Publications
2011-01-01
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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=2011;volume=36;issue=1;spage=29;epage=34;aulast=Thangavelu |
| _version_ | 1819053128338636800 |
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| author | Sundaram Thangavelu S Jayakumar K N Govindarajan Sanjay S Supe V Nagarajan M Nagarajan |
| author_facet | Sundaram Thangavelu S Jayakumar K N Govindarajan Sanjay S Supe V Nagarajan M Nagarajan |
| author_sort | Sundaram Thangavelu |
| collection | DOAJ |
| description | The goal of the present study was to study the effects of low- and high-energy intensity-modulated photon beams on the planning of target volume and the critical organs in cases of localized prostate tumors in a cohort of 8 patients. To ensure that the difference between the plans is due to energy alone, all other parameters were kept constant. A mean dose volume histogram (DVH) for each value of energy and for each contoured structure was created and was considered as completely representative for all patients. To facilitate comparison between 6-MV and 15-MV beams, the DVH-s were normalized. The different parameters that were compared for 6-MV and 15-MV beams included mean DVH, different homogeneity indices, conformity index, etc. Analysis of several indices depicts more homogeneous dose for 15-MV beam and more conformity for 6-MV beam. Comparison of all these parameters showed that there was little difference between the 6-MV and 15-MV beams. For rectum, 2 to 4 % more volume received high dose with the 6-MV beam in comparison with the 15-MV beam, which was not clinically significant, since in practice much tighter constraints are maintained, such that Normal Tissue Complication Probability (NTCP) is kept within 5 %. Such tighter constraints might increase the dose to other regions and other critical organs but are unlikely to increase their complication probabilities. Hence the slight advantages of 15-MV beam in providing benefits of better normal-tissue sparing and better coverage cannot be considered to outweigh its well-known risk of non-negligible neutron production. |
| first_indexed | 2024-12-21T12:30:48Z |
| format | Article |
| id | doaj.art-e4417ecfbb9d433cae3dc0c6882d3e1a |
| institution | Directory Open Access Journal |
| issn | 0971-6203 1998-3913 |
| language | English |
| last_indexed | 2024-12-21T12:30:48Z |
| publishDate | 2011-01-01 |
| publisher | Wolters Kluwer Medknow Publications |
| record_format | Article |
| series | Journal of Medical Physics |
| spelling | doaj.art-e4417ecfbb9d433cae3dc0c6882d3e1a2022-12-21T19:04:03ZengWolters Kluwer Medknow PublicationsJournal of Medical Physics0971-62031998-39132011-01-01361293410.4103/0971-6203.75469Influence of photon energy on the quality of prostate intensity modulated radiation therapy plans based on analysis of physical indicesSundaram ThangaveluS JayakumarK N GovindarajanSanjay S SupeV NagarajanM NagarajanThe goal of the present study was to study the effects of low- and high-energy intensity-modulated photon beams on the planning of target volume and the critical organs in cases of localized prostate tumors in a cohort of 8 patients. To ensure that the difference between the plans is due to energy alone, all other parameters were kept constant. A mean dose volume histogram (DVH) for each value of energy and for each contoured structure was created and was considered as completely representative for all patients. To facilitate comparison between 6-MV and 15-MV beams, the DVH-s were normalized. The different parameters that were compared for 6-MV and 15-MV beams included mean DVH, different homogeneity indices, conformity index, etc. Analysis of several indices depicts more homogeneous dose for 15-MV beam and more conformity for 6-MV beam. Comparison of all these parameters showed that there was little difference between the 6-MV and 15-MV beams. For rectum, 2 to 4 % more volume received high dose with the 6-MV beam in comparison with the 15-MV beam, which was not clinically significant, since in practice much tighter constraints are maintained, such that Normal Tissue Complication Probability (NTCP) is kept within 5 %. Such tighter constraints might increase the dose to other regions and other critical organs but are unlikely to increase their complication probabilities. Hence the slight advantages of 15-MV beam in providing benefits of better normal-tissue sparing and better coverage cannot be considered to outweigh its well-known risk of non-negligible neutron production.http://www.jmp.org.in/article.asp?issn=0971-6203;year=2011;volume=36;issue=1;spage=29;epage=34;aulast=ThangaveluEnergyH-indexHI-indexnormal tissue complication probabilityprostate intensity-modulated radiation therapySigma-indextumor control probability |
| spellingShingle | Sundaram Thangavelu S Jayakumar K N Govindarajan Sanjay S Supe V Nagarajan M Nagarajan Influence of photon energy on the quality of prostate intensity modulated radiation therapy plans based on analysis of physical indices Journal of Medical Physics Energy H-index HI-index normal tissue complication probability prostate intensity-modulated radiation therapy Sigma-index tumor control probability |
| title | Influence of photon energy on the quality of prostate intensity modulated radiation therapy plans based on analysis of physical indices |
| title_full | Influence of photon energy on the quality of prostate intensity modulated radiation therapy plans based on analysis of physical indices |
| title_fullStr | Influence of photon energy on the quality of prostate intensity modulated radiation therapy plans based on analysis of physical indices |
| title_full_unstemmed | Influence of photon energy on the quality of prostate intensity modulated radiation therapy plans based on analysis of physical indices |
| title_short | Influence of photon energy on the quality of prostate intensity modulated radiation therapy plans based on analysis of physical indices |
| title_sort | influence of photon energy on the quality of prostate intensity modulated radiation therapy plans based on analysis of physical indices |
| topic | Energy H-index HI-index normal tissue complication probability prostate intensity-modulated radiation therapy Sigma-index tumor control probability |
| url | http://www.jmp.org.in/article.asp?issn=0971-6203;year=2011;volume=36;issue=1;spage=29;epage=34;aulast=Thangavelu |
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