scholarly journals Improved dosimetric accuracy with semi‐automatic contour propagation of organs‐at‐risk in glioblastoma patients undergoing chemoradiation

2019 ◽  
Vol 20 (12) ◽  
pp. 45-53 ◽  
Author(s):  
Sangjune Lee ◽  
James Stewart ◽  
Young Lee ◽  
Sten Myrehaug ◽  
Arjun Sahgal ◽  
...  
Keyword(s):  
At Risk ◽  
Organs At Risk ◽  
Contour Propagation ◽  
Dosimetric Accuracy ◽  
Automatic Contour

Automatic Contour Propagation of Organs-at-Risk on Serial MRIs and Dosimetric Implications in Glioblastoma Patients Undergoing Chemo-Radiation

2018 ◽  
Vol 102 (3) ◽  
pp. e349
Author(s):  
S.L. Lee ◽  
J. Stewart ◽  
S.D. Myrehaug ◽  
A. Sahgal ◽  
M.E. Ruschin ◽  
...  
Keyword(s):  
At Risk ◽  
Organs At Risk ◽  
Contour Propagation ◽  
Automatic Contour

scholarly journals EP-1890: Accurate organs at risk contour propagation in head and neck adaptive radiotherapy

2016 ◽  
Vol 119 ◽  
pp. S893-S894
Author(s):  
T.T. Zhai ◽  
H.P. Bijl ◽  
J.A. Langendijk ◽  
R.J. Steenbakkers ◽  
C.L. Brouwer ◽  
...  
Keyword(s):  
At Risk ◽  
Head And Neck ◽  
Organs At Risk ◽  
Adaptive Radiotherapy ◽  
Contour Propagation

scholarly journals Evaluation of automatic contour propagation in T2-weighted 4DMRI for normal-tissue motion assessment using internal organ-at-risk volume (IRV)

2018 ◽  
Vol 19 (5) ◽  
pp. 598-608 ◽  
Author(s):  
Jingjing Zhang ◽  
Svetlana Markova ◽  
Alejandro Garcia ◽  
Kirk Huang ◽  
Xingyu Nie ◽  
...  
Keyword(s):  
At Risk ◽  
Normal Tissue ◽  
Contour Propagation ◽  
Organ At Risk ◽  
Motion Assessment ◽  
Tissue Motion ◽  
Automatic Contour

scholarly journals Comprehensive and Clinically Accurate Head and Neck Organs at Risk Delineation via Stratified Deep Learning: A Large-scale Multi-Institutional Study

2021 ◽  
Author(s):  
Dazhou Guo ◽  
Jia Ge ◽  
Xianghua Ye ◽  
Senxiang Yan ◽  
Yi Xin ◽  
...  
Keyword(s):  
At Risk ◽  
Deep Learning ◽  
Head And Neck ◽  
Large Scale ◽  
Organs At Risk ◽  
Labor Cost ◽  
Network Architectures ◽  
Institutional Evaluation ◽  
Dosimetric Accuracy ◽  
Organ At Risk

Abstract Accurate organ at risk (OAR) segmentation is critical to reduce the radiotherapy post-treatment complications. Consensus guidelines recommend a set of more than 40 OARs in the head and neck (H&N) region, however, due to the predictable prohibitive labor-cost of this task, most institutions choose a substantially simplified protocol by delineating a smaller subset of OARs and neglecting the dose distributions associated with other OARs. In this work we propose a novel, automated and highly effective stratified OAR segmentation (SOARS) system using deep learning to precisely delineate a comprehensive set of 42 H&N OARs. SOARS stratifies 42 OARs into anchor, mid-level, and small & hard subcategories, with specifically derived neural network architectures for each category by neural architecture search (NAS) principles. We built SOARS models using 176 training patients in an internal institution and independently evaluated on 1327 external patients across six different institutions. It consistently outperformed other state-of-the-art methods by at least 3-5% in Dice score for each institutional evaluation (up to 36% relative error reduction in other metrics). More importantly, extensive multi-user studies evidently demonstrated that 98% of the SOARS predictions need only very minor or no revisions for direct clinical acceptance (saving 90% radiation oncologists workload), and their segmentation and dosimetric accuracy are within or smaller than the inter-user variation. These findings confirmed the strong clinical applicability of SOARS for the OAR delineation process in H&N cancer radiotherapy workflows, with improved efficiency, comprehensiveness, and quality.

Deformable Contour Propagation of Organs at Risk in Adaptive Head and Neck Radiation Therapy

2014 ◽  
Vol 90 (1) ◽  
pp. S867
Author(s):  
L. Tachiki ◽  
V. Sehgal ◽  
J. Pasha ◽  
J. Ducote ◽  
P. Daroui ◽  
...  
Keyword(s):  
At Risk ◽  
Radiation Therapy ◽  
Head And Neck ◽  
Organs At Risk ◽  
Deformable Contour ◽  
Contour Propagation ◽  
Head And Neck Radiation

Estimation of absorbed radiation doses to skin and S‐values for organs at risk due to nasal administration of PET agents using Monte Carlo simulations

2021 ◽  
Author(s):  
Jim O’Doherty ◽  
Colby D. Mangini ◽  
David M. Hamby ◽  
David Boozer ◽  
Nisha Singh ◽  
...  
Keyword(s):  
At Risk ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Organs At Risk ◽  
Nasal Administration ◽  
Radiation Doses

26 CT-based treatment planning in gynecological IDR-brachytherapy — questions on PTV and tolerance dose in organs at risk

1998 ◽  
Vol 47 ◽  
pp. S7 ◽  
Author(s):  
E. Weiss ◽  
O. Pradier ◽  
D. Laurent ◽  
C.F. Hess
Keyword(s):  
At Risk ◽  
Treatment Planning ◽  
Organs At Risk ◽  
Tolerance Dose

scholarly journals Evaluation of the influence of susceptibility-induced magnetic field distortions on the precision of contouring intracranial organs at risk for stereotactic radiosurgery

2020 ◽  
Vol 15 ◽  
pp. 91-97
Author(s):  
Veit Mengling ◽  
Florian Putz ◽  
Frederik Bernd Laun ◽  
Rosalind Perrin ◽  
Felix Eisenhut ◽  
...  
Keyword(s):  
Magnetic Field ◽  
At Risk ◽  
Stereotactic Radiosurgery ◽  
Organs At Risk ◽  
Induced Magnetic Field

scholarly journals Use of a Head-Tilting Baseplate During Tomotherapy to Shorten the Irradiation Time and Protect the Hippocampus and Lens in Hippocampal Sparing-Whole Brain Radiotherapy

2021 ◽  
Vol 20 ◽  
pp. 153303382098682
Author(s):  
Kosei Miura ◽  
Hiromasa Kurosaki ◽  
Nobuko Utsumi ◽  
Hideyuki Sakurai
Keyword(s):  
At Risk ◽  
Planning Target Volume ◽  
Irradiation Time ◽  
Organs At Risk ◽  
Absorbed Dose ◽  
Whole Brain Radiotherapy ◽  
Target Volume ◽  
Whole Brain ◽  
Brain Radiotherapy ◽  
Hippocampal Sparing

Purpose: The aim of this study is to comparatively examine the possibility of reducing the exposure dose to organs at risk, such as the hippocampus and lens, and improving the dose distribution of the planned target volume with and without the use of a head-tilting base plate in hippocampal-sparing whole-brain radiotherapy using tomotherapy. Methods: Five paired images of planned head computed tomography without and with tilt were analyzed. The hippocampus and planning target volume were contoured according to the RTOG 0933 contouring atlas protocol. The hippocampal zone to be avoided was delineated using a 5-mm margin. The prescribed radiation dose was 30 Gy in 10 fractions. The absorbed dose to planning target volume dose, absorbed dose to the organ at risk, and irradiation time were evaluated. The paired t-test was used to analyze the differences between hippocampal-sparing whole-brain radiotherapy with head tilts and without head tilts. Results: Hippocampal-sparing whole-brain radiotherapy with tilt was not superior in planning target volume doses using the homogeneity index than that without tilt; however, it showed better values, and for Dmean and D2%, the values were closer to 30 Gy. Regarding the hippocampus, dose reduction with tilt was significantly greater at Dmax, Dmean, and Dmin, whereas regarding the lens, it was significantly greater at Dmax and Dmin. The irradiation time was also predominantly shorter. Conclusion: In our study, a tilted hippocampal-sparing whole-brain radiotherapy reduced the irradiation time by >10%. Therefore, our study indicated that hippocampal-sparing whole-brain radiotherapy with tomotherapy should be performed with a tilt. The head-tilting technique might be useful during hippocampal-sparing whole-brain radiotherapy. This method could decrease the radiation exposure time, while sparing healthy organs, including the hippocampus and lens.

scholarly journals Effects of deep inspiration breath hold on prone photon or proton irradiation of breast and regional lymph nodes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bruno Speleers ◽  
Max Schoepen ◽  
Francesca Belosi ◽  
Vincent Vakaet ◽  
Wilfried De Neve ◽  
...  
Keyword(s):  
Lung Cancer ◽  
At Risk ◽  
Lymph Node ◽  
Organs At Risk ◽  
Lymph Node Status ◽  
Breath Hold ◽  
Deep Inspiration ◽  
Proton Radiotherapy ◽  
Regional Lymph Nodes ◽  
Deep Inspiration Breath Hold

AbstractWe report on a comparative dosimetrical study between deep inspiration breath hold (DIBH) and shallow breathing (SB) in prone crawl position for photon and proton radiotherapy of whole breast (WB) and locoregional lymph node regions, including the internal mammary chain (LN_MI). We investigate the dosimetrical effects of DIBH in prone crawl position on organs-at-risk for both photon and proton plans. For each modality, we further estimate the effects of lung and heart doses on the mortality risks of different risk profiles of patients. Thirty-one patients with invasive carcinoma of the left breast and pathologically confirmed positive lymph node status were included in this study. DIBH significantly decreased dose to heart for photon and proton radiotherapy. DIBH also decreased lung doses for photons, while increased lung doses were observed using protons because the retracting heart is displaced by low-density lung tissue. For other organs-at-risk, DIBH resulted in significant dose reductions using photons while minor differences in dose deposition between DIBH and SB were observed using protons. In patients with high risks for cardiac and lung cancer mortality, average thirty-year mortality rates from radiotherapy-related cardiac injury and lung cancer were estimated at 3.12% (photon DIBH), 4.03% (photon SB), 1.80% (proton DIBH) and 1.66% (proton SB). The radiation-related mortality risk could not outweigh the ~ 8% disease-specific survival benefit of WB + LN_MI radiotherapy in any of the assessed treatments.

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