The Experts below are selected from a list of 6303 Experts worldwide ranked by ideXlab platform
Ritsuko Komaki - One of the best experts on this subject based on the ideXlab platform.
-
determination of respiratory motion for distal Esophagus cancer using four dimensional computed tomography
International Journal of Radiation Oncology Biology Physics, 2008Co-Authors: Brian P Yaremko, Thomas Guerrero, Mary Frances Mcaleer, Kara M Bucci, Josue Noyolamartinez, Linda T Nguyen, Peter A Balter, Rudy Guerra, Ritsuko KomakiAbstract:Purpose To investigate the motion characteristics of distal Esophagus cancer primary Tumors using four-dimensional computed tomography (4D CT). Methods and Materials Thirty-one consecutive patients treated for Esophagus cancer who received respiratory-gated 4D CT imaging for treatment planning were selected. Deformable image registration was used to map the full expiratory motion gross Tumor volume (GTV) to the full-inspiratory CT image, allowing quantitative assessment of each voxel's displacement. These displacements were correlated with patient Tumor and respiratory characteristics. Results The mean (SE) tidal volume was 608 (73) mL. The mean GTV volume was 64.3 (10.7) mL on expiration and 64.1 (10.7) mL on inspiration (no significant difference). The mean Tumor motion in the x-direction was 0.13 (0.006) cm (average of absolute values), in the y-direction 0.23 (0.01) cm (anteriorly), and in the z-direction 0.71 (0.02) cm (inferiorly). Tumor motion correlated with tidal volume. Comparison of Tumor motion above vs. below the diaphragm was significant for the average net displacement ( p = 0.014), motion below the diaphragm was greater than above. From the cumulative distribution 95% of the Tumors moved less than 0.80 cm radially and 1.75 cm inferiorly. Conclusions Primary Esophagus Tumor motion was evaluated with 4D CT. According to the results of this study, when 4D CT is not available, a radial margin of 0.8 cm and axial margin of ±1.8 cm would provide Tumor motion coverage for 95% of the cases in our study population.
Thomas Guerrero - One of the best experts on this subject based on the ideXlab platform.
-
determination of respiratory motion for distal Esophagus cancer using four dimensional computed tomography
International Journal of Radiation Oncology Biology Physics, 2008Co-Authors: Brian P Yaremko, Thomas Guerrero, Mary Frances Mcaleer, Kara M Bucci, Josue Noyolamartinez, Linda T Nguyen, Peter A Balter, Rudy Guerra, Ritsuko KomakiAbstract:Purpose To investigate the motion characteristics of distal Esophagus cancer primary Tumors using four-dimensional computed tomography (4D CT). Methods and Materials Thirty-one consecutive patients treated for Esophagus cancer who received respiratory-gated 4D CT imaging for treatment planning were selected. Deformable image registration was used to map the full expiratory motion gross Tumor volume (GTV) to the full-inspiratory CT image, allowing quantitative assessment of each voxel's displacement. These displacements were correlated with patient Tumor and respiratory characteristics. Results The mean (SE) tidal volume was 608 (73) mL. The mean GTV volume was 64.3 (10.7) mL on expiration and 64.1 (10.7) mL on inspiration (no significant difference). The mean Tumor motion in the x-direction was 0.13 (0.006) cm (average of absolute values), in the y-direction 0.23 (0.01) cm (anteriorly), and in the z-direction 0.71 (0.02) cm (inferiorly). Tumor motion correlated with tidal volume. Comparison of Tumor motion above vs. below the diaphragm was significant for the average net displacement ( p = 0.014), motion below the diaphragm was greater than above. From the cumulative distribution 95% of the Tumors moved less than 0.80 cm radially and 1.75 cm inferiorly. Conclusions Primary Esophagus Tumor motion was evaluated with 4D CT. According to the results of this study, when 4D CT is not available, a radial margin of 0.8 cm and axial margin of ±1.8 cm would provide Tumor motion coverage for 95% of the cases in our study population.
Chen-kan Tseng - One of the best experts on this subject based on the ideXlab platform.
-
accurate esophageal gross Tumor volume segmentation in pet ct using two stream chained 3d deep network fusion
Medical Image Computing and Computer-Assisted Intervention, 2019Co-Authors: Dakai Jin, Dazhou Guo, Adam P. Harrison, Jing Xiao, Chen-kan TsengAbstract:Gross Tumor volume (GTV) segmentation is a critical step in esophageal cancer radiotherapy treatment planning. Inconsistencies across oncologists and prohibitive labor costs motivate automated approaches for this task. However, leading approaches are only applied to radiotherapy computed tomography (RTCT) images taken prior to treatment. This limits the performance as RTCT suffers from low contrast between the Esophagus, Tumor, and surrounding tissues. In this paper, we aim to exploit both RTCT and positron emission tomography (PET) imaging modalities to facilitate more accurate GTV segmentation. By utilizing PET, we emulate medical professionals who frequently delineate GTV boundaries through observation of the RTCT images obtained after prescribing radiotherapy and PET/CT images acquired earlier for cancer staging. To take advantage of both modalities, we present a two-stream chained segmentation approach that effectively fuses the CT and PET modalities via early and late 3D deep-network-based fusion. Furthermore, to effect the fusion and segmentation we propose a simple yet effective progressive semantically nested network (PSNN) model that outperforms more complicated models. Extensive 5-fold cross-validation on 110 esophageal cancer patients, the largest analysis to date, demonstrates that both the proposed two-stream chained segmentation pipeline and the PSNN model can significantly improve the quantitative performance over the previous state-of-the-art work by \(11\%\) in absolute Dice score (DSC) (from \(0.654\, \pm \, 0.210\) to \(0.764\, \pm \, 0.134\)) and, at the same time, reducing the Hausdorff distance from \(129\pm 73\) mm to \(47 \pm 56\) mm.
Kuni Ohtomo - One of the best experts on this subject based on the ideXlab platform.
-
four dimensional measurement of the displacement of internal fiducial markers during 320 multislice computed tomography scanning of thoracic esophageal cancer
International Journal of Radiation Oncology Biology Physics, 2011Co-Authors: Hideomi Yamashita, Satoshi Kida, A Sakumi, Akihiro Haga, Saori Ito, Tsuyoshi Onoe, Kae Okuma, Kenji Ino, Masaaki Akahane, Kuni OhtomoAbstract:Purpose To investigate the three-dimensional movement of internal fiducial markers placed near esophageal cancers using 320-multislice CT. Methods and Materials This study examined 22 metal markers in the esophageal wall near the primary Tumors of 12 patients treated with external-beam photon radiotherapy. Motion assessment was analyzed in 41 respiratory phases during 20 s of cine CT in the radiotherapy position. Results Motion in the cranial–caudal (CC) direction showed a strong correlation ( R 2 > 0.4) with the respiratory curve in most markers (73%). The average absolute amplitude of the marker movement was 1.5 ± 1.6 mm, 1.6 ± 1.7 mm, and 3.3 ± 3.3 mm in the left–right (LR), anterior–posterior (AP), and CC directions, respectively. The average marker displacements in the CC direction between peak exhalation and inhalation for the 22 clips were 1.1 mm (maximum, 5.5 mm), 3.0 mm (14.5 mm), and 5.1 mm (16.3 mm) for the upper, middle, and lower thoracic Esophagus, respectively. Conclusions Motion in primary Esophagus Tumor was evaluated with 320-multislice CT. According to this study, 4.3 mm CC, 1.5 mm AP, and 2.0 mm LR in the upper, 7.4 mm CC, 3.0 mm AP, and 2.4 mm LR in the middle, and 13.8 mm CC, 6.6 mm AP, and 6.8 mm LR in the lower thoracic Esophagus provided coverage of Tumor motion in 95% of the cases in our study population.
Brian P Yaremko - One of the best experts on this subject based on the ideXlab platform.
-
determination of respiratory motion for distal Esophagus cancer using four dimensional computed tomography
International Journal of Radiation Oncology Biology Physics, 2008Co-Authors: Brian P Yaremko, Thomas Guerrero, Mary Frances Mcaleer, Kara M Bucci, Josue Noyolamartinez, Linda T Nguyen, Peter A Balter, Rudy Guerra, Ritsuko KomakiAbstract:Purpose To investigate the motion characteristics of distal Esophagus cancer primary Tumors using four-dimensional computed tomography (4D CT). Methods and Materials Thirty-one consecutive patients treated for Esophagus cancer who received respiratory-gated 4D CT imaging for treatment planning were selected. Deformable image registration was used to map the full expiratory motion gross Tumor volume (GTV) to the full-inspiratory CT image, allowing quantitative assessment of each voxel's displacement. These displacements were correlated with patient Tumor and respiratory characteristics. Results The mean (SE) tidal volume was 608 (73) mL. The mean GTV volume was 64.3 (10.7) mL on expiration and 64.1 (10.7) mL on inspiration (no significant difference). The mean Tumor motion in the x-direction was 0.13 (0.006) cm (average of absolute values), in the y-direction 0.23 (0.01) cm (anteriorly), and in the z-direction 0.71 (0.02) cm (inferiorly). Tumor motion correlated with tidal volume. Comparison of Tumor motion above vs. below the diaphragm was significant for the average net displacement ( p = 0.014), motion below the diaphragm was greater than above. From the cumulative distribution 95% of the Tumors moved less than 0.80 cm radially and 1.75 cm inferiorly. Conclusions Primary Esophagus Tumor motion was evaluated with 4D CT. According to the results of this study, when 4D CT is not available, a radial margin of 0.8 cm and axial margin of ±1.8 cm would provide Tumor motion coverage for 95% of the cases in our study population.