Interobserver variations in gross tumor volume delineation of brain tumors on computed tomography and impact of magnetic resonance imaging

Weltens, Caroline; Menten, Johan; Féron, Michel; Bellon, Erwin; Demaerel, Philippe; Maes, Frederik; Bogaert, Walter Van den; Schueren, Emmanuel van der

doi:10.1016/s0167-8140(01)00371-1

Cited by 167 publications

(139 citation statements)

References 21 publications

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“…These 3D images provide readily-acquired multiplanar reformations and depict more focal lesions than T1-weighted SE images [15] . Although our mean interobserver concordance rate should be higher than in earlier studies that employed conventional MR images [3][4][5] , considerable interobserver differences for GTV contouring persisted; our lowest concordance rate was 56.5% ( Figure 2). The "double reading" system presented here can be a valuable method for the integration of GTV contouring.…”

Section: Discussioncontrasting

confidence: 66%

“…A∩B = 0) to 100% (perfect concordance) and is very sensitive to small variations in overlap because it is normalized to the union of the volumes. For example, if two equal volumes overlap by 50% each, the concordance index is 33% [5,6] . Statistical analyses were with statistical software (MedCalc version 9.2.1.0; MedCalc Software, Mariakerke, Belgium).…”

Section: Discussionmentioning

confidence: 99%

“…Experimental studies that evaluated the consistency of GTV assessments demonstrated substantial intra-and interobserver variability even among experienced readers [3][4][5][6][7][8][9] . Therefore, we designed and attempted RT planning with a preliminary-contouring system in 50 glioblastoma patients.…”

Section: Discussionmentioning

confidence: 99%

“…On the other hand, the GTV must be contoured consensually on a case-by-case basis. In spite of contouring protocols on multimodal registered images, e.g., contrast-enhanced computed tomography (CT), magnetic resonance (MR) imaging, and positron emission tomography (PET), previous studies revealed that intra-and interobserver variability in GTV assessment persists [3][4][5][6][7][8][9] . However, reported data demonstrated the experimental contouring but the practical GTV in RT planning.…”

Section: Introductionmentioning

confidence: 99%

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Double reading for gross tumor volume assessment in radiotherapy planning

Murakami

Hirai

Toya

et al. 2012

JST

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Background/Objective: The precise definition of the gross tumor volume (GTV) that takes into account intra-and interobserver variability is necessary for high-precision radiotherapy (RT) techniques. The purpose of this study was to demonstrate the practical GTV assessment by a "double reading" approach.Methods: Pretreatment magnetic resonance (MR) imaging, including the post-contrast 3D magnetization-prepared rapid-gradient echo (MP-RAGE) sequence (section thickness 1.0 mm) was performed on a 3T superconducting imager in 50 patients with glioblastoma. MR images were transferred to a RT planning system (RTPS) that provides many opportunities for GTV contouring, e.g., at diagnosis, surgical navigation, and RT deliberations. Independent 2 observers preliminarily contoured the GTV on MR images. After planning-CT scanning, CT images with a 1.0 mm slice interval were transferred to the RTPS, registered with the diagnostic images, and then the preliminarily-contoured strictures were copied onto the CT images and used for GTV assessment. The practical GTV on the planning CT was determined by integrating the interpretations and adding information on postoperative changes. The interobserver variability in GTV contouring was assessed by Bland-Altman analysis and the concordance index.Results: There was substantial interobserver variability in GTV contouring (95% limits of agreement: -29.4%, 16.8%). The mean interobserver concordance rate for the GTV was 82.1% (range 56.5-91.2%). The practical GTVs were significantly larger than the preliminarily-contoured GTVs by both observers (p < 0.01).Conclusions: Considering interobserver variability, "double reading" is necessary for practical GTV assessment. This approach for volume assessment may facilitate the standardization of treatments, not only of RT but also of surgery and chemotherapy.

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Section: Discussioncontrasting

confidence: 66%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Double reading for gross tumor volume assessment in radiotherapy planning

Murakami

Hirai

Toya

et al. 2012

JST

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“…Several studies reported failures of individual expert rater segmentations because structural MRI may obscure the precise visual delineation of glioma boundaries [10][11][12]. In addition, manual segmentation is time-consuming and is a rate-determining step for further treatment planning [13].…”

Section: Introductionmentioning

confidence: 99%

Multi-modal Glioblastoma Segmentation: Man versus Machine

Porz¹,

Bauer²,

Pica³

et al. 2014

J Neurol Surg A Cent Eur Neurosurg

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A multi‐institutional analysis of a general pelvis continuous Hounsfield unit synthetic CT software for radiotherapy

Keyriläinen

Suilamo

et al. 2021

J Applied Clin Med Phys

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Purpose: To validate a synthetic computed tomography (sCT) software with continuous HUs and large field-of-view (FOV) coverage for magnetic resonance imaging (MRI)-only workflow of general pelvis anatomy in radiotherapy (RT). Methods: An sCT software for general pelvis anatomy (prostate, rectum, and female pelvis) has been developed by Philips Healthcare and includes continuous HUs assignment along with large FOV coverage. General pelvis sCTs were generated using a two-stack T1-weighted mDixon fast-field echo (FFE) sequence with a superior-inferior coverage of 36 cm. Seventy-seven prostate, 43 rectum, and 27 gynecological cases were scanned by three different institutions. mDixon image quality and sCTs were evaluated for soft tissue contrast by using a confidence level scale from 1 to 5 for bladder, prostate/rectum interface, mesorectum, and fiducial maker visibility. Dosimetric comparison was performed by recalculating the RT plans on the sCT after rigid registration. For 12 randomly selected cases, the mean absolute error (MAE) between sCT and CT was calculated to evaluate HU similarity, and the Pearson correlation coefficients (PCC) between the CT-and sCT-generated digitally reconstructed radiographs (DRRs) were obtained for quantitative comparison. To examine geometric accuracy of sCT as a reference for cone beam CT (CBCT), the difference between bone-based alignment of CBCT to CT and CBCT to sCT was obtained for 19 online-acquired CBCTs from three patients. Results: Two-stack mDixon scans with large FOV did not show any image inhomogeneity or fat-water swap artifact. Fiducials, Foley catheter, and even rectal spacer were visible as dark signal on the sCT. Average visibility confidence level (average AE standard deviation) on the sCT was 5.0 AE 0.0, 4.6 AE 0.5, 3.8 AE 0.4, and 4.0 AE 1.1 for bladder, prostate/rectum interface, mesorectum and fiducial markers. Dosimetric accuracy showed on average < 1% difference with the CT-based plans for target and normal structures. The MAE of bone and soft tissue between the sCT and CT are 120.9 AE 15.4 HU, 33.4 AE 4.1 HU, respectively. Average PCC of all evaluated DRR pairs was 0.975. The average offset between CT and sCT as reference was (LR, AP, SI) = (0.19 AE 0.35, 0.14 AE 0.60, 0.44 AE 0.54) mm.

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Interobserver variations in gross tumor volume delineation of brain tumors on computed tomography and impact of magnetic resonance imaging

Cited by 167 publications

References 21 publications

Double reading for gross tumor volume assessment in radiotherapy planning

Double reading for gross tumor volume assessment in radiotherapy planning

Multi-modal Glioblastoma Segmentation: Man versus Machine

A multi‐institutional analysis of a general pelvis continuous Hounsfield unit synthetic CT software for radiotherapy

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