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- Breast cancer (4)
- Proton therapy (2)
- Radiotherapy (2)
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- VMAT beam complexity (2)
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- ATM (1)
- Adaptive radiotherapy (1)
- Axillary node (1)
- BOC-IMPTLET (1)
- Blood dosimetry (1)
- Brain metastases (1)
- Collimator rotation (1)
- Deep learning (1)
- Deep-learning (1)
- Diffuse large B cell lymphoma (1)
- Electron beams (1)
- FDG-PET (1)
- Gantry rotation (1)
- HER2-positive (1)
- Head and neck cancer (1)
- Hepatocellular carcinoma (1)
- IMPT (1)
- Internal lead shielding (1)
- Isocentricity (1)
- Linac (1)
- Low-risk (1)
- Lynch syndrome (1)
- Neoadjuvant chemotherapy (1)
- Optical tracking (1)
- Optimization algorithm (1)
Articles 1 - 19 of 19
Full-Text Articles in Medicine and Health Sciences
1756 Evaluating The Impact Of Prophylactic Intrathecal Chemotherapy In Diffuse Large B Cell Lymphoma (Dlbcl) Patients With High Central Nervous System International Prognostic Index (Cns-Ipi) Scores: A Comprehensive Review And Meta-Analysis, Kadhim Al-Banaa, Alfarooq Alshaikhli, Shyam Poudel, Shiva Shrotria, Can Wang, Paul Hanona, Swathi Gopishetty, Precious Idogun, Daniel Ezekwudo, Ishmael Jaiyesimi
1756 Evaluating The Impact Of Prophylactic Intrathecal Chemotherapy In Diffuse Large B Cell Lymphoma (Dlbcl) Patients With High Central Nervous System International Prognostic Index (Cns-Ipi) Scores: A Comprehensive Review And Meta-Analysis, Kadhim Al-Banaa, Alfarooq Alshaikhli, Shyam Poudel, Shiva Shrotria, Can Wang, Paul Hanona, Swathi Gopishetty, Precious Idogun, Daniel Ezekwudo, Ishmael Jaiyesimi
Conference Presentation Abstracts
No abstract provided.
Nrg-Br008: A Phase Iii Randomized Trial Of Radiotherapy Optimization For Low-Risk Her2-Positive Breast Cancer (Hero), L Braunstein, M Mitchell, H Bandos, W Sikov, A Khan, Peter Chen, P Ganz, R Jagsi, J White, R Cecchini
Nrg-Br008: A Phase Iii Randomized Trial Of Radiotherapy Optimization For Low-Risk Her2-Positive Breast Cancer (Hero), L Braunstein, M Mitchell, H Bandos, W Sikov, A Khan, Peter Chen, P Ganz, R Jagsi, J White, R Cecchini
Conference Presentation Abstracts
Background: Breast radiotherapy (RT) is the standard of care for patients with early-stage breast cancer (BC) who undergo breast-conserving surgery (BCS). However, the magnitude of benefit of RT is less clear in BCS patients with low-risk disease who receive effective systemic therapy. Among patients with early-stage HER2-positive (HER2+) BC, 10-year locoregional recurrence has been reported as low as 1.5% following BCS, adjuvant chemotherapy and HER2-targeted therapy, and RT. Given these exceedingly favorable outcomes, with the addition of HER2-directed therapy, we seek to evaluate the feasibility of omitting RT among patients with early-stage HER2+ BC following BCS and appropriate systemic therapy. …
Loco-Regional Irradiation In Patients With Biopsy-Proven Axillary Node Involvement At Presentation Who Become Pathologically Node-Negative After Neoadjuvant Chemotherapy: Primary Outcomes Of Nrg Oncology/Nsabp B-51/Rtog 1304, E Mamounas, H Bandos, J White, T Julian, A Khan, S Shaitelman, M Torres, Frank Vicini, P Ganz, Andrew Muskovitz
Loco-Regional Irradiation In Patients With Biopsy-Proven Axillary Node Involvement At Presentation Who Become Pathologically Node-Negative After Neoadjuvant Chemotherapy: Primary Outcomes Of Nrg Oncology/Nsabp B-51/Rtog 1304, E Mamounas, H Bandos, J White, T Julian, A Khan, S Shaitelman, M Torres, Frank Vicini, P Ganz, Andrew Muskovitz
Conference Presentation Abstracts
No abstract provided.
Characteristics Of Breast Cancer In Carriers Of Pathogenic Variant In Atm In A Large Academic Health Center, Ujjwal Karki, Tara Rangarajan, Dana Zakalik
Characteristics Of Breast Cancer In Carriers Of Pathogenic Variant In Atm In A Large Academic Health Center, Ujjwal Karki, Tara Rangarajan, Dana Zakalik
Conference Presentation Abstracts
Background: Pathogenic variants (PVs) in ATM are associated with an increased risk of breast, pancreas, and other cancers. The clinical and pathological characteristics of ATM-associated breast cancers have not been well defined. Methods: Patients who underwent multigene panel testing between December 2012 and May 2023 and were identified to harbor ATM PVs were included in the study. We analyzed demographics, germline findings, histopathology, genomic recurrence score, and management of ATM PV carriers with breast cancer. Results: A total of 222 individuals were identified to have PVs in ATM, of whom 184 (83%) were female. The majority were Caucasian (n = …
Breast Cancer In Pms2 Related Lynch Syndrome: Evidence Of A Possible Association?, Ujjwal Karki, Tara Rangarajan, Dana Zakalik
Breast Cancer In Pms2 Related Lynch Syndrome: Evidence Of A Possible Association?, Ujjwal Karki, Tara Rangarajan, Dana Zakalik
Conference Presentation Abstracts
Background: Lynch syndrome (LS) is a hereditary cancer predisposition syndrome caused by pathogenic variants (PVs) in mismatch repair genes, MLH1, MSH2, MSH6, and PMS2. LS is associated with increased risk of colorectal, and endometrial cancers but breast cancer risk is uncertain, with some studies suggesting MSH6 and PMS2 PVs may have a higher risk for breast cancer. Our study outlines the incidence and clinical characteristics of breast cancer in PMS2-related LS identified at a large academic center. Methods: Patients with PMS2 PVs identified between July 2009 and May 2023 were selected from a database at the Nancy and James Grosfeld …
Linac-Based Srs Treatments Slow Down Unnecessarily Due To Parked Leaf Optimization, Brian Loughery, Cory S. Knill, Raminder P. Sandhu, Lifeng Lin, Jian Liang
Linac-Based Srs Treatments Slow Down Unnecessarily Due To Parked Leaf Optimization, Brian Loughery, Cory S. Knill, Raminder P. Sandhu, Lifeng Lin, Jian Liang
Conference Presentation Abstracts
Purpose: It was observed on a VersaHD that clinical SRS deliveries created in the Elements treatment planning system (TPS) slowed gantry rotation and dose rate to allow parked MLC leaves to move into position for use in an upcoming control point. Gantry rotation slowed suddenly, visibly backtracking to previous gantry angles. The purpose of this work is to study the effect of parked MLC positioning parameters in Elements on cranial SRS delivery speed and gantry motion on a VersaHD. Methods: To study the effect of parked MLC leaf positions on VersaHD deliverability, cranial SRS plans were generated with different TPS …
The Clinical Usability, Efficiency, And Accuracy Of Combining Deep-Learning-Based Synthetic Ct And Auto-Contouring For Daily Cbct-Based Online Adaptive Radiation Therapy, An Qin, J Xu, N O'Connell, Xuanfeng Ding, Shupeng Chen, D Thill
The Clinical Usability, Efficiency, And Accuracy Of Combining Deep-Learning-Based Synthetic Ct And Auto-Contouring For Daily Cbct-Based Online Adaptive Radiation Therapy, An Qin, J Xu, N O'Connell, Xuanfeng Ding, Shupeng Chen, D Thill
Conference Presentation Abstracts
Purpose: To evaluate the feasibility of deep-learning and CBCT-based online adaptive radiotherapy(ART) in thorax, Head&Neck, and pelvic regions. Methods: The study utilized ADMIRE(Advanced Medical Image Registration Engine), a research software designed to enable fast online ART through: (1)synthetic CT(sCT) generation from CBCT, (2)automatic segmentation of critical organs(OARs), and(3)deformable image registration(DIR) to transfer the target volume. ADMIRE trained a modified Cycle-Generative-Adversarial-Networks with Structural Similarity Index Map(SSIM) loss term to generate sCT, while the auto-segmentation model was based on a 3D-ResUnet with modification. Site-specific models were trained for three anatomic sites: thorax, pelvic, and head&neck, and for both networks. The study included …
Application Of A Novel Optical Tool For Linac Calibrations, Cory S. Knill, Brian Loughery, Raminder P. Sandhu, Lifeng Lin, Mark Stefani
Application Of A Novel Optical Tool For Linac Calibrations, Cory S. Knill, Brian Loughery, Raminder P. Sandhu, Lifeng Lin, Mark Stefani
Conference Presentation Abstracts
Purpose: Maintaining a linac within tight stereotactic isocentricity tolerances requires minimizing errors in individual components of the linac. However, while isocentricity can be measured using a Winston-Lutz test, contributions from individual components can be difficult to discern. The disconnect between how individual components contribute to isocentricity can lead to lengthy troubleshooting exercises when isocentricity is outside tolerance. To provide more info rmation to physicists and increase the speed of isocentricity adjustments, a new tool that uses optical tracking to investigate and adjust individual linac components that contribute to isocentricity was tested on three clinical linacs. Methods: The optical tracking tool …
Internal Lead Shielding For Clinical Electron Treatments, Patrick N. Mcdermott
Internal Lead Shielding For Clinical Electron Treatments, Patrick N. Mcdermott
Conference Presentation Abstracts
Purpose: Electron beams are often used to treat superficial lesions of the lip, cheek, nose and ear. Lead is frequently used to block distal structures. It is customary to place an internal bolus of low atomic number in between the tissue and the lead to reduce electron backscatter from the lead. Space for the lead and the internal bolus is quite limited. The current method, recommended by TG25, for estimating the thickness of the lead plus internal bolus is not self-consistent and leads to a larger than necessary thickness. Furthermore, this method uses an older expression for the electron backscatter …
A Novel Planning Framework For The Efficient Spot-Scanning Proton Arc Therapy Via The Particle Swarm Optimization (Sparc-Particle Swarm), Y Qian, R Dao, G Liu, Xiaoqiang Li, H Quan, Xuanfeng Ding
A Novel Planning Framework For The Efficient Spot-Scanning Proton Arc Therapy Via The Particle Swarm Optimization (Sparc-Particle Swarm), Y Qian, R Dao, G Liu, Xiaoqiang Li, H Quan, Xuanfeng Ding
Conference Presentation Abstracts
Purpose: The delivery efficiency is the bottleneck of spot-scanning proton arc therapy (SPArc) because of the numerous energy layers (EL) ascending switches. This study aims to develop a new algorithm to mitigate the need of EL ascending via water equivalent thickness (WET) sector selection followed by the particle swarm optimization (SPArc- particle swarm). Methods: SPArc- particle swarm divided the full arc trajectory into the optimal sectors based on the K-means clustering analysis of the relative mean WET. Within the sector, particle swarm optimization was used to minimize the total energy switch time, in which it optimized the energy selection integrated …
Individual Vmat Beam Complexity Indices Have Limited Predictive Value For Qa Pass-Rates, Jian Liang, Q Liu, David T. To, Michael G. Snyder
Individual Vmat Beam Complexity Indices Have Limited Predictive Value For Qa Pass-Rates, Jian Liang, Q Liu, David T. To, Michael G. Snyder
Conference Presentation Abstracts
Purpose: Previous studies with sample sizes <400 have indicated that VMAT beam complexity indices may have a relationship with measured QA pass-rates. The aim of this study is to evaluate such relationships on a large scale to further investigate their strength. Methods: Total of 17,273 VMAT QA results across 8 Elekta Agility machines were used in this study. All beams were flattened 6MV or 10MV. Sun Nuclear ArcCheck was used for QA measurements with γ-analysis parameters of 10% threshold, 3% dose difference, 2mm distance to agreement, and 95% passing threshold. A total 214 Beams (1.23%) failed QA. QA distributions in Pinnacle were calculated with 2 degree gantry intervals and a dose grid of 2mm. Four complexity indices (MCSv, MU weighted Segment Area, Segment Area/Perimeter, and Average Leaf Gap) were computed. Spearman’s correlations were evaluated for each, and cut-off values for the indices were sought to indicate values above which no QA failures would be expected. Results: Evaluation of the 4 complexity metrics showed weak correlation with QA pass rates (< ±0.42) with high significance (p < 0.001). When metrics were evaluated independently, cut-off values from correlation plots separated only 0.67%, 0.72%, 2.2%, 6.3% guaranteed passing beams from the total sample, respectively. When evaluating whether anymetric for a given beam exceeded its cut-off, the fraction of guaranteed passing beams rose to only 6.6%. However, when cut-off values for one metric were allowed to be functionally dependent upon another, the fraction of guaranteed passing beams increased. For MU weighted Segment Area andAverage Leaf Gap, a dependent approach separated 19.1% guaranteed passing beams from the sample. Conclusion: Individual complexity metrics have weak predictive utility in assessing plan performance. However, using multiple complexity cut-off functions with dependence upon more than one metric increased the fraction of predicted passing beams by around 300%.
Predicting Tumor Voxel Dose-Response Using Deep Learning On Serial Fdg-Pet Feedback Images, Shupeng Chen, Di Yan, An Qin, Rohan Deraniyagala, Daniel Krauss, Peter Chen, Craig Stevens
Predicting Tumor Voxel Dose-Response Using Deep Learning On Serial Fdg-Pet Feedback Images, Shupeng Chen, Di Yan, An Qin, Rohan Deraniyagala, Daniel Krauss, Peter Chen, Craig Stevens
Conference Presentation Abstracts
Purpose: Tumor voxel dose-response matrix (DRM) can be assessed using a series of FDG-PET/CT feedback images acquired during radiotherapy. Predicting the tumor voxel DRM earlier is crucial for treatment adaptation. However, it is also challenging due to FDG fluctuation in tumor cells. This study investigated the feasibility of predicting DRM during early treatment weeks using deep learning (DL). Methods: FDG-PET images were acquired at the pretreatment (preTx), the 2nd and 4th weeks during chemo-radiotherapy (35×2Gy) from 50 head and neck patients. The reference value of tumor voxel DRM (DRMref), representing the average metabolic change ratio during the treatment, was determined …
Develop A Novel Beam Orientation Optimization Algorithm For Let (Linear Energy Transfer) Incorporated Impt (Intensity Modulated Proton Therapy) (Imptlet, R Dao, Y Qian, Xiaoqiang Li, H Quan, Xuanfeng Ding, G Liu
Develop A Novel Beam Orientation Optimization Algorithm For Let (Linear Energy Transfer) Incorporated Impt (Intensity Modulated Proton Therapy) (Imptlet, R Dao, Y Qian, Xiaoqiang Li, H Quan, Xuanfeng Ding, G Liu
Conference Presentation Abstracts
Purpose: To improve the dose and LET distribution in the IMPTLET, we introduce a new optimization algorithm to search for the optimal beam orientation and count through the arc trajectory (BOC-IMPTLET). Methods: We introduce kmeans clustering analysis in the BOC-IMPTLET algorithm by analyzing the distribution of LET in the target from the full arc trajectory. The optimal of cluster count was used as beam count, which was determined based on the SSE (Sum of Square Error) value and the angle of the corresponding centroid of each cluster was used as beam orientation, respectively. The BOC-IMPTLET algorithm was implemented in the …
Comparison Of Vmat Beam Complexity With Different Mlc Collimator Rotation And Their Impact On Psqa Pass Rates, David T. To, Michael G. Snyder, Jian Liang
Comparison Of Vmat Beam Complexity With Different Mlc Collimator Rotation And Their Impact On Psqa Pass Rates, David T. To, Michael G. Snyder, Jian Liang
Conference Presentation Abstracts
Purpose: I t has been previously shown that utilizing a collimator angle of ±45° has demonstrated a reduction in MU and VMAT beam complexity. Studies have demonstrated this for VMAT prostate plans with small sample size. In this study we evaluate multiple collimator angles with a larger sample size and different treatment sites. Methods: A total of 17273 VMAT beams were evaluated with beam collimator rotations of 0°, ±5°, ±10°, ±15°, ±30°, ±45°, and ±90°. QA Gamma pass rates for our institution use a 3%/2mm criteria 10% threshold with 95% limit pass rate utilizing Sun Nuclear ArcCheck (helical diode array). …
A Comprehensive Investigation Of Linear Energy Transfer Optimization Effectiveness In Intensity-Modulated Proton Therapy Via Alternating Direction Method Of Multipliers (Impt Let-Admm), Q Fan, G Liu, Lili Zhao, Xiaoqiang Li, Xuanfeng Ding, S Dai
A Comprehensive Investigation Of Linear Energy Transfer Optimization Effectiveness In Intensity-Modulated Proton Therapy Via Alternating Direction Method Of Multipliers (Impt Let-Admm), Q Fan, G Liu, Lili Zhao, Xiaoqiang Li, Xuanfeng Ding, S Dai
Conference Presentation Abstracts
Linear energy transfer (LET)-guided optimization in intensity-modulated proton therapy (IMPT) via alternating direction method of multipliers (ADMM) has the potential to improve its biological effectiveness (IMPTLET- ADMM), in which the LET distribution in target can be escalated, while the LET distribution in the organs at risk can be mitigated. This study aims to quantitatively investigate the effectiveness of LET optimization in IMPT via ADMM with different solvers in its iteration loop. Methods: The clinical dose-volume-histogram (DVH) constraint noted dose sub-problem and clinical LET -volume-histogram (LVH) constraint noted LET sub-problem are combined to generate a composite objective function, which is available …
An Analytic Model Of The External Beam Dose Rate Effect On Immune Cells In Blood Dosimetry, Lili Zhao, Peilin Liu, G Liu, Xuanfeng Ding
An Analytic Model Of The External Beam Dose Rate Effect On Immune Cells In Blood Dosimetry, Lili Zhao, Peilin Liu, G Liu, Xuanfeng Ding
Conference Presentation Abstracts
Purpose: Radiation therapy is a double-edged sword with regard to its immunomodulatory effect. It is critical to find how it is affected by dose rate. Thus, we developed an analytic model for calculating the number of immune cells receiving radiation. Methods: Suppose the blood is received radiation by constant dose rate. The blood is one-way flow without circulation in the radiation delivery at a constant velocity. Two kinds of lung treatment regimens were considered standard delivery 2Gy per fx total 30fx and hypo-fractionation SBRT 12 Gy per fx total 5 fx. Two different dose rates were simulated for standard treatment: …
Particle Arc Single-Isocenter Stereotactic Radiosurgery Of Multiple Brain Metastases, L Volz, S Mein, T Tessonnier, Peilin Liu, A Mairani, M Durante, Xuanfeng Ding, C Graeff, T Li
Particle Arc Single-Isocenter Stereotactic Radiosurgery Of Multiple Brain Metastases, L Volz, S Mein, T Tessonnier, Peilin Liu, A Mairani, M Durante, Xuanfeng Ding, C Graeff, T Li
Conference Presentation Abstracts
Purpose: To develop spot-scanning proton (SPArc) and heavy ion (SHArc) arc therapy for single-isocenter stereotatic radiosurgery (SISRS) of multiple brain metastases (MBMs). First results achieved with dedicated planning infrastructure are compared to state-of-the -art volumetric modulated photon arc therapy (HA-VMAT). Methods: A multi-institutional collaboration was established to develop bespoke SPArc and SHArc SISRS infrastructure with available research and commercial treatment planning systems. Devised planning and delivery methods considered dedicated energy, spot, and multi-arc selection strategies. SPArc and SHArc (carbon and helium ions) plans were generated for MBM patients exhibiting 3-12 intracranial lesions with GTV volumes between 0.03ccm and 19.8ccm, at …
Investigate The Delivery Efficiency Improvement For Sparc Compared To Impt, Peilin Liu, B A. De Jong, S Chang, Lili Zhao, G Liu, Craig Stevens, Rohan Deraniyagala, E W. Korevaar, J A. Langendijk, Xiaoqiang Li, Xuanfeng Ding
Investigate The Delivery Efficiency Improvement For Sparc Compared To Impt, Peilin Liu, B A. De Jong, S Chang, Lili Zhao, G Liu, Craig Stevens, Rohan Deraniyagala, E W. Korevaar, J A. Langendijk, Xiaoqiang Li, Xuanfeng Ding
Conference Presentation Abstracts
Purpose: To assess the efficiency improvement of SPArc compared to IMPT in proton clinical operation.Methods: A random clinical operation day at a proton therapy center with a two room system. Aa total of 10 Head & Neck cancer cases treated on Jan 6th, 2021were selected and SPArc plans were generated for all the cases with similar target coverage and dose constraints of organ at risk (OARs). 3% range uncertainties and 3mm setup uncertainties were applied for robust optimization. The log files of clinical IMPT were exported to calculate true treatment delivery time. The machine-specific delivery sequence model was utilized to …
Does Proton Arc Therapy Has Potential Clinical Benefits For Hepatocellular Carcinoma?, Peilin Liu, R Dalfsen, M Soukup, Shupeng Chen, Lili Zhao, Z Wang, X S. Gao, Thomas Quinn, Craig Stevens, Rohan Deraniyagala, Xiaoqiang Li, Xuanfeng Ding
Does Proton Arc Therapy Has Potential Clinical Benefits For Hepatocellular Carcinoma?, Peilin Liu, R Dalfsen, M Soukup, Shupeng Chen, Lili Zhao, Z Wang, X S. Gao, Thomas Quinn, Craig Stevens, Rohan Deraniyagala, Xiaoqiang Li, Xuanfeng Ding
Conference Presentation Abstracts
Purpose: To investigate the potential clinical benefits and dose-averaged Linear Energy Transfer (LETd) sparing, utilizing proton arc plan for Hepatocellular carcinoma (HCC) patients in comparison with Intensity Modulated Proton Therapy (IMPT). Methods: Ten HCC patients have been retrospectively selected. Two planning groups were created: Proton Arc plans using Monaco ver. 6 and the clinical IMPT plan. Both planning groups used the same robustness parameters. The prescription dose is 67.5 Gy (RBE) in 15 fractions/ 66 GyE in 10 fractions of the Clinical Target Volume (CTV) following clinical IMPT plan. Robustness evaluations were performed to ensure target dose coverage. Normal Tissue …