Throwing the dart blind-folded: comparison of computed tomography versus magnetic resonance imaging-guided brachytherapy for cervical cancer with regard to dose received by the ‘actual’ targets and organs at risk
Purpose : Computed tomography (CT) is inferior to magnetic resonance imaging (MRI) in cervical tumor delineation, but similar in identification of organs at risk (OAR). The trend to over-estimate high-risk and low-risk clinical target volume (HRCTV, IRCTV) on CT can lead to under-estimation of dose...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Termedia Publishing House
2017-10-01
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| Series: | Journal of Contemporary Brachytherapy |
| Subjects: | |
| Online Access: | https://www.termedia.pl/Throwing-the-dart-blind-folded-comparison-of-computed-tomography-versus-magnetic-resonance-imaging-guided-brachytherapy-for-cervical-cancer-with-regard-to-dose-received-by-the-actual-targets-and-organ,54,30887,1,1.html |
| _version_ | 1818522699905892352 |
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| author | Winnie Wing Ling Yip Joyce Siu Yu Wong Venus Wan Yan Lee Frank Chi Sing Wong Stewart Yuk Tung |
| author_facet | Winnie Wing Ling Yip Joyce Siu Yu Wong Venus Wan Yan Lee Frank Chi Sing Wong Stewart Yuk Tung |
| author_sort | Winnie Wing Ling Yip |
| collection | DOAJ |
| description | Purpose : Computed tomography (CT) is inferior to magnetic resonance imaging (MRI) in cervical tumor delineation, but similar in identification of organs at risk (OAR). The trend to over-estimate high-risk and low-risk clinical target volume (HRCTV, IRCTV) on CT can lead to under-estimation of dose received by 90% (D 90 ) of the ‘actual’ CTV. This study aims to evaluate whether CT-guided planning delivers adequate dose to the ‘actual’ targets while spares the OAR similarly.
Material and methods : MRI-guided high-dose-rate image-guided brachytherapy (IGBT) was performed in 11 patients. The pre-brachytherapy CTs were retrospectively contoured to generate CT-guided plans. MRI-based contours (HRCTV mri , IRCTV mri , bladder mri , rectum mri , and sigmoid mri ) were fused to CT plans for dosimetric comparison with MRI-guided plans. Paired 2-tailed t-test and Wilcoxon signed-rank test were used to analyze data.
Results : 63.6% of CT plans achieved the HRCTV mri D 90 constraint (≥ 7.2 Gy in one fraction), compared with 90.9% for MRI plans. > 90% of both modalities achieved the OAR’s constraints (EMBRACE). The percentage of CT and MRI plans that achieved the aims (EMBRACE II) for bladder, rectum, and sigmoid were 36.4% vs. 81.8%, 63.6% vs. 63.6%, and 72.7% vs. 72.7%, respectively. There were no statistically significant differences in HRCTV mri D 90 , IRCTV mri D 90 , or dose received by the most exposed 2 cm3 (D 2cc ) of OARmri between the modalities. Excluding the CT plans not achieving HRCTV mri D 90 constraint, there were significant increase in bladder mri D 2cc , rectum mri D 2cc , and sigmoid mri D 2cc , compared with MRI plans (0.9 Gy/Fr, 95% CI 0.2-1.5, p = 0.018; 0.9 Gy/Fr, 95% CI 0.3-1.4, p = 0.009; 0.5 Gy/Fr, 95% CI 0.2-0.9, p = 0.027, respectively).
Conclusions : MRI-based IGBT remains the gold standard. CT planning may compromise HRCTV mri D 90 or increase OARmriD 2cc , which could decrease local control or increase treatment toxicity. |
| first_indexed | 2024-12-11T05:36:33Z |
| format | Article |
| id | doaj.art-bc09809a117544d7a8819132987eb366 |
| institution | Directory Open Access Journal |
| issn | 1689-832X 2081-2841 |
| language | English |
| last_indexed | 2024-12-11T05:36:33Z |
| publishDate | 2017-10-01 |
| publisher | Termedia Publishing House |
| record_format | Article |
| series | Journal of Contemporary Brachytherapy |
| spelling | doaj.art-bc09809a117544d7a8819132987eb3662022-12-22T01:19:16ZengTermedia Publishing HouseJournal of Contemporary Brachytherapy1689-832X2081-28412017-10-019544645210.5114/jcb.2017.7105030887Throwing the dart blind-folded: comparison of computed tomography versus magnetic resonance imaging-guided brachytherapy for cervical cancer with regard to dose received by the ‘actual’ targets and organs at riskWinnie Wing Ling YipJoyce Siu Yu WongVenus Wan Yan LeeFrank Chi Sing WongStewart Yuk TungPurpose : Computed tomography (CT) is inferior to magnetic resonance imaging (MRI) in cervical tumor delineation, but similar in identification of organs at risk (OAR). The trend to over-estimate high-risk and low-risk clinical target volume (HRCTV, IRCTV) on CT can lead to under-estimation of dose received by 90% (D 90 ) of the ‘actual’ CTV. This study aims to evaluate whether CT-guided planning delivers adequate dose to the ‘actual’ targets while spares the OAR similarly. Material and methods : MRI-guided high-dose-rate image-guided brachytherapy (IGBT) was performed in 11 patients. The pre-brachytherapy CTs were retrospectively contoured to generate CT-guided plans. MRI-based contours (HRCTV mri , IRCTV mri , bladder mri , rectum mri , and sigmoid mri ) were fused to CT plans for dosimetric comparison with MRI-guided plans. Paired 2-tailed t-test and Wilcoxon signed-rank test were used to analyze data. Results : 63.6% of CT plans achieved the HRCTV mri D 90 constraint (≥ 7.2 Gy in one fraction), compared with 90.9% for MRI plans. > 90% of both modalities achieved the OAR’s constraints (EMBRACE). The percentage of CT and MRI plans that achieved the aims (EMBRACE II) for bladder, rectum, and sigmoid were 36.4% vs. 81.8%, 63.6% vs. 63.6%, and 72.7% vs. 72.7%, respectively. There were no statistically significant differences in HRCTV mri D 90 , IRCTV mri D 90 , or dose received by the most exposed 2 cm3 (D 2cc ) of OARmri between the modalities. Excluding the CT plans not achieving HRCTV mri D 90 constraint, there were significant increase in bladder mri D 2cc , rectum mri D 2cc , and sigmoid mri D 2cc , compared with MRI plans (0.9 Gy/Fr, 95% CI 0.2-1.5, p = 0.018; 0.9 Gy/Fr, 95% CI 0.3-1.4, p = 0.009; 0.5 Gy/Fr, 95% CI 0.2-0.9, p = 0.027, respectively). Conclusions : MRI-based IGBT remains the gold standard. CT planning may compromise HRCTV mri D 90 or increase OARmriD 2cc , which could decrease local control or increase treatment toxicity.https://www.termedia.pl/Throwing-the-dart-blind-folded-comparison-of-computed-tomography-versus-magnetic-resonance-imaging-guided-brachytherapy-for-cervical-cancer-with-regard-to-dose-received-by-the-actual-targets-and-organ,54,30887,1,1.htmlbrachytherapy cervical cancer CT MRI |
| spellingShingle | Winnie Wing Ling Yip Joyce Siu Yu Wong Venus Wan Yan Lee Frank Chi Sing Wong Stewart Yuk Tung Throwing the dart blind-folded: comparison of computed tomography versus magnetic resonance imaging-guided brachytherapy for cervical cancer with regard to dose received by the ‘actual’ targets and organs at risk Journal of Contemporary Brachytherapy brachytherapy cervical cancer CT MRI |
| title | Throwing the dart blind-folded: comparison of computed tomography versus magnetic resonance imaging-guided brachytherapy for cervical cancer with regard to dose received by the ‘actual’ targets and organs at risk |
| title_full | Throwing the dart blind-folded: comparison of computed tomography versus magnetic resonance imaging-guided brachytherapy for cervical cancer with regard to dose received by the ‘actual’ targets and organs at risk |
| title_fullStr | Throwing the dart blind-folded: comparison of computed tomography versus magnetic resonance imaging-guided brachytherapy for cervical cancer with regard to dose received by the ‘actual’ targets and organs at risk |
| title_full_unstemmed | Throwing the dart blind-folded: comparison of computed tomography versus magnetic resonance imaging-guided brachytherapy for cervical cancer with regard to dose received by the ‘actual’ targets and organs at risk |
| title_short | Throwing the dart blind-folded: comparison of computed tomography versus magnetic resonance imaging-guided brachytherapy for cervical cancer with regard to dose received by the ‘actual’ targets and organs at risk |
| title_sort | throwing the dart blind folded comparison of computed tomography versus magnetic resonance imaging guided brachytherapy for cervical cancer with regard to dose received by the actual targets and organs at risk |
| topic | brachytherapy cervical cancer CT MRI |
| url | https://www.termedia.pl/Throwing-the-dart-blind-folded-comparison-of-computed-tomography-versus-magnetic-resonance-imaging-guided-brachytherapy-for-cervical-cancer-with-regard-to-dose-received-by-the-actual-targets-and-organ,54,30887,1,1.html |
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