Inter-Observer Variability in MR-Based Target Volume Delineation of Uveal Melanoma
Purpose: Several efforts are being undertaken toward MRI-based treatment planning for ocular proton therapy for uveal melanoma (UM). The interobserver variability of the gross target volume (GTV) on magnetic resonance imaging (MRI) is one of the important parameters to design safety margins for a re...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2023-05-01
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| Series: | Advances in Radiation Oncology |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S245210942200255X |
| _version_ | 1797955459044343808 |
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| author | Myriam G. Jaarsma-Coes Lisa Klaassen Berit M. Verbist T.H. Khanh Vu Yvonne L.B. Klaver Myra F. Rodrigues Claire Nabarro Gregorius P.M. Luyten Coen R.N. Rasch Marcel van Herk Jan-Willem M. Beenakker |
| author_facet | Myriam G. Jaarsma-Coes Lisa Klaassen Berit M. Verbist T.H. Khanh Vu Yvonne L.B. Klaver Myra F. Rodrigues Claire Nabarro Gregorius P.M. Luyten Coen R.N. Rasch Marcel van Herk Jan-Willem M. Beenakker |
| author_sort | Myriam G. Jaarsma-Coes |
| collection | DOAJ |
| description | Purpose: Several efforts are being undertaken toward MRI-based treatment planning for ocular proton therapy for uveal melanoma (UM). The interobserver variability of the gross target volume (GTV) on magnetic resonance imaging (MRI) is one of the important parameters to design safety margins for a reliable treatment. Therefore, this study assessed the interobserver variation in GTV delineation of UM on MRI. Methods and Materials: Six observers delineated the GTV in 10 different patients using the Big Brother contouring software. Patients were scanned at 3T MRI with a surface coil, and tumors were delineated separately on contrast enhanced 3DT1 (T1gd) and 3DT2-weighted scans with an isotropic acquisition resolution of 0.8 mm. Volume difference and overall local variation (median standard deviation of the distance between the delineated contours and the median contour) were analyzed for each GTV. Additionally, the local variation was analyzed for 4 interfaces: sclera, vitreous, retinal detachment, and tumor-choroid interface. Results: The average GTV was significantly larger on T1gd (0.57cm3) compared with T2 (0.51cm3, P = .01). A not significant higher interobserver variation was found on T1gd (0.41 mm) compared with T2 (0.35 mm). The largest variations were found at the tumor-choroid interface due to peritumoral enhancement (T1gd, 0.62 mm; T2, 0.52 mm). As a result, a larger part of this tumor-choroid interface appeared to be included on T1gd-based GTVs compared with T2, explaining the smaller volumes on T2. Conclusions: The interobserver variation of 0.4 mm on MRI are low with respect to the voxel size of 0.8 mm, enabling small treatment margins. We recommend delineation based on the T1gd-weighted scans, as choroidal tumor extensions might be missed. |
| first_indexed | 2024-04-10T23:33:28Z |
| format | Article |
| id | doaj.art-fb963844cd714ed6bff0e6e22991f411 |
| institution | Directory Open Access Journal |
| issn | 2452-1094 |
| language | English |
| last_indexed | 2024-04-10T23:33:28Z |
| publishDate | 2023-05-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Advances in Radiation Oncology |
| spelling | doaj.art-fb963844cd714ed6bff0e6e22991f4112023-01-12T04:19:37ZengElsevierAdvances in Radiation Oncology2452-10942023-05-0183101149Inter-Observer Variability in MR-Based Target Volume Delineation of Uveal MelanomaMyriam G. Jaarsma-Coes0Lisa Klaassen1Berit M. Verbist2T.H. Khanh Vu3Yvonne L.B. Klaver4Myra F. Rodrigues5Claire Nabarro6Gregorius P.M. Luyten7Coen R.N. Rasch8Marcel van Herk9Jan-Willem M. Beenakker10Leiden University Medical Center, Ophthalmology, Leiden, Netherlands; Leiden University Medical Center, Radiology, Leiden, NetherlandsLeiden University Medical Center, Ophthalmology, Leiden, Netherlands; Leiden University Medical Center, Radiology, Leiden, NetherlandsLeiden University Medical Center, Radiology, Leiden, NetherlandsLeiden University Medical Center, Ophthalmology, Leiden, NetherlandsHollandPTC, Radiation oncology, Delft, Netherlands; Leiden University Medical Center, Radiation Oncology, Leiden, NetherlandsHollandPTC, Radiation oncology, Delft, Netherlands; Leiden University Medical Center, Radiation Oncology, Leiden, NetherlandsLeiden University Medical Center, Radiology, Leiden, NetherlandsLeiden University Medical Center, Ophthalmology, Leiden, NetherlandsHollandPTC, Radiation oncology, Delft, Netherlands; Leiden University Medical Center, Radiation Oncology, Leiden, NetherlandsDivision of Cancer Sciences, University of Manchester, Manchester, United KingdomLeiden University Medical Center, Ophthalmology, Leiden, Netherlands; Leiden University Medical Center, Radiology, Leiden, Netherlands; Leiden University Medical Center, Radiation Oncology, Leiden, Netherlands; Corresponding author: Jan-Willem M. BeenakkerPurpose: Several efforts are being undertaken toward MRI-based treatment planning for ocular proton therapy for uveal melanoma (UM). The interobserver variability of the gross target volume (GTV) on magnetic resonance imaging (MRI) is one of the important parameters to design safety margins for a reliable treatment. Therefore, this study assessed the interobserver variation in GTV delineation of UM on MRI. Methods and Materials: Six observers delineated the GTV in 10 different patients using the Big Brother contouring software. Patients were scanned at 3T MRI with a surface coil, and tumors were delineated separately on contrast enhanced 3DT1 (T1gd) and 3DT2-weighted scans with an isotropic acquisition resolution of 0.8 mm. Volume difference and overall local variation (median standard deviation of the distance between the delineated contours and the median contour) were analyzed for each GTV. Additionally, the local variation was analyzed for 4 interfaces: sclera, vitreous, retinal detachment, and tumor-choroid interface. Results: The average GTV was significantly larger on T1gd (0.57cm3) compared with T2 (0.51cm3, P = .01). A not significant higher interobserver variation was found on T1gd (0.41 mm) compared with T2 (0.35 mm). The largest variations were found at the tumor-choroid interface due to peritumoral enhancement (T1gd, 0.62 mm; T2, 0.52 mm). As a result, a larger part of this tumor-choroid interface appeared to be included on T1gd-based GTVs compared with T2, explaining the smaller volumes on T2. Conclusions: The interobserver variation of 0.4 mm on MRI are low with respect to the voxel size of 0.8 mm, enabling small treatment margins. We recommend delineation based on the T1gd-weighted scans, as choroidal tumor extensions might be missed.http://www.sciencedirect.com/science/article/pii/S245210942200255X |
| spellingShingle | Myriam G. Jaarsma-Coes Lisa Klaassen Berit M. Verbist T.H. Khanh Vu Yvonne L.B. Klaver Myra F. Rodrigues Claire Nabarro Gregorius P.M. Luyten Coen R.N. Rasch Marcel van Herk Jan-Willem M. Beenakker Inter-Observer Variability in MR-Based Target Volume Delineation of Uveal Melanoma Advances in Radiation Oncology |
| title | Inter-Observer Variability in MR-Based Target Volume Delineation of Uveal Melanoma |
| title_full | Inter-Observer Variability in MR-Based Target Volume Delineation of Uveal Melanoma |
| title_fullStr | Inter-Observer Variability in MR-Based Target Volume Delineation of Uveal Melanoma |
| title_full_unstemmed | Inter-Observer Variability in MR-Based Target Volume Delineation of Uveal Melanoma |
| title_short | Inter-Observer Variability in MR-Based Target Volume Delineation of Uveal Melanoma |
| title_sort | inter observer variability in mr based target volume delineation of uveal melanoma |
| url | http://www.sciencedirect.com/science/article/pii/S245210942200255X |
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