Citations

Mayo Clinic

Clear

587 citation(s) found for "Xu, Ding".

Abstract WMP27: Differential Gene Expression in Coiled Versus Flow-diverter Treated Aneurysms: a RNA-Seq Analysis in Rabbit Aneurysm Model
Johnson, Collin R., Thielen, Evan , Schroeder, Dana , Ding, Yong Hong, Kallmes, David F. , Kadirvel, Ramanathan , Rouchaud, Aymeric , Ding, Yonghong , Dai, Daying , Cebral, Juan R.

Stroke | March 20, 2022 | Volume: 47 | Issue: suppl_1 | Pages: No page available

10.1161/str.47.suppl_1.wmp27 Get It

Introduction: Numerous endovascular tools exist for the treatment of intracranial aneurysms with an increased use of flow-diverting devices in recent years. However, the biological mechanisms leading to aneurysm healing or potential complications such as delayed aneurysm ruptures after flow-diverter treatment are not yet well established. We used RNA-sequencing technology to identify genes relevant for biological impact of coils and flow-diverters in elastase-induced saccular aneurysms in rabbits and to identify genes and pathways of potential clinical interest. Methods: Elastase-induced saccular aneurysms were created at the origin of the right common carotid artery. Aneurysms were treated with coils (n=5) or flow-diverters (Pipeline Embolic Device, Covidien, CA) (n=4). Untreated aneurysms (n=6) were used as controls. Messenger RNA and microRNA were isolated from the aneurysms at 4 weeks following treatment. RNA samples were processed using RNA-seq technology. RNA-seq results were analyzed by using the Ingenuity Pathway Analysis tool. Results: Using RNA sequencing for coiled versus non-treated aneurysms, 464 genes were found to be differentially expressed with 58 genes down regulated and 406 genes up regulated. Using the same criteria for the flow-diverter treated aneurysms, 177 genes were found to be differentially expressed with 8 genes down regulated and 169 genes up regulated. Comparing coiled versus flow-diverter treated aneurysms, 13 genes were significantly differentially expressed with 8 down regulated and 5 up regulated genes. Genes identified with the highest interest for aneurysms healing were fibroblast growth factor-23, matrix metalloproteinases (MMP)-1, Scinderin and Basigin (implicated in MMP-2 and MMP-9 regulation). Pathway analysis associated these genes with inflammatory response, cellular migration, and coagulation, among other functions. Conclusions: RNA-sequencing analysis of rabbit aneurysms revealed differential regulation of some key pathways, including inflammation and cellular migration that could explain the different biological mechanisms implicated in aneurysms healing either after coiling or flow-diverter treatments and could explain potential device-related complications.
Abstract W P78: Gene Expression Comparison of Flow Diversion and Coiling in an Experimental Aneurysm Model
Puffer, Cole, Kallmes, David F. , Kadirvel, Ram , Ding, Yonghong , Dai, Daying , Cebral, Juan R. , Kadirvel, Ramanathan

Stroke | March 20, 2022 | Volume: 46 | Issue: suppl_1 | Pages: No page available

10.1161/str.46.suppl_1.wp78 Get It

Backgound and Purpose: Mechanisms of both healing and complications, including spontaneous aneurysm rupture, remain unclear following flow diverter treatment. The aim of the current study was to compare the gene expression of various key molecules involved in the healing of aneurysms between aneurysms treated with microcoils and flow diverters. Methods: Saccular aneurysms were created in rabbits (n=12). Aneurysms were either treated with coils (n=6) or with flow diverters (n=6). Aneurysm tissue was harvested at four weeks following treatment and used for gene expression and zymography experiments. Genes with a fold change of 1.2 or greater were considered up regulated, whereas those with a fold change of 0.8 or less were considered down regulated. Results: All coil embolized aneurysms were completely occluded at follow up. Two aneurysms were occluded and the remaining four samples were incompletely occluded in the flow diverter treated group. The following genes were expressed at lower levels in the flow diverter group as compared to the coiled aneurysm group: genes encoding proteinases (matrix metalloproteinases -2 and -9), cellular markers (endothelial nitric oxide synthase and smooth muscle actin), and structural proteins (collagens and fibronectin). Genes related to inflammation (tumor necrosis factor-α and monocyte chemoattractant protein -1) were up regulated in flow diverter treated aneurysms compared to coil embolized aneurysms. Notably, the enzymatic activity of active MMP-9 was high in aneurysms treated with flow diverters. Conclusion: As compared to coiled aneurysms, the molecular milieu surrounding aneurysms treated with flow diverters is characterized by higher levels of activated proteases, elevated expression of genes encoding inflammatory proteins, and diminished expression of genes encoding structural proteins. These data may provide improved understanding of rupture risk and healing following aneurysm treatment, and inform development of therapies aimed at lowering rupture risk and accelerating healing.
Abstract P200: Transcriptional Regulation of tcap Conveys an Inhibitory Mechanotransductive Response to Modulate Cardiomyocyte Size
Yang, Jingchun , Sun, Xiaojing , Ding, Yonghe , Xu, Xiaolei

Circulation Research | March 20, 2022 | Volume: 109 | Issue: suppl_1 | Pages: No page available

10.1161/res.109.suppl_1.ap200 Get It

To sense and to respond to mechanical stimuli is a fundamental process of cardiomyocytes during both heart development and diseases. However, how mechanical stimuli control cardiomyocyte size remains elusive. Here, we report a novel inhibitory mechanotransductive response suggested by loss-of-functions studies of α-Actinin2 (Actn2), a predominant sarcomeric Z-disc protein. During zebrafish cardiogenesis, depletion of Actn2 results in a defective Z-disc, while other sarcomeric substructures remain normal. As a consequence, ventricle chamber size is severely reduced. Interestingly, this chamber size reduction can be rescued by the cessation of heart contraction, suggesting the involvement of an inhibitory mechanotransductive reponse. At the molecular level, both tcapa and tcapb, two zebrafish tcap homologues that are transcriptionally responsive to stretch, are transcriptionally activated in actn2 knockdown embryos while activation of these gene results in smaller cardiomyocytes. Depletion of either gene rescues the reduced cardiomyocyte size in actn2 knockdown embryos. Consistent to embryonic studies, tcaps are transcriptionally activated during pathogenesis of anemia-induced cardiomyopathy, while over expression of tcapa via transgenics exerts a cardioprotective effect. Together, we conclude that transcriptional regulation of tcaps conveys a novel inhibitory mechanotransductive response that modulates cardiomyocyte size during both zebrafish cardiogenesis and adult cardiac remodeling.
Abstract 6: Characteristics and Outcomes of Ischemic Heart Failure Patients With Improved Ejection Fraction After Coronary Revascularization
Wang, Shaoping , Peng, Ding , Liu, Jinghua , Dunlay, Shannon M. , Chamberlain, Alanna M. , Borah, Bijan J.

Circulation: Cardiovascular Quality and Outcomes | March 20, 2022 | Volume: 11 | Issue: suppl_1 | Pages: No page available

10.1161/circoutcomes.11.suppl_1.6 Get It

Background: Heart failure (HF) with improved ejection fraction (HFiEF) is defined as a new subset in addition to the subsets of HF with reduced EF (≤40%; HFrEF) and HF with preserved EF (>40%). The characteristics and outcomes of patients with ischemic HFiEF after coronary revascularization are unknown. Methods and Results: We identified 1,816 patients with coronary artery diseases and reduced EF (≤40%) in a large hospital in China, who underwent either coronary artery bypass graft surgery (n=1,126) or percutaneous coronary intervention with drug eluting stent (n=687) from January 2005 to December 2014. All patients had EF reassessment during follow-up. The improvement of EF peaked at 3 months and persisted for more than one year after revascularization. Thus, 589 patients who had EF reassessment between 3 to 12 months after revascularization were included in the definitions of HFiEF and HFrEF patient cohort and subsequent survival analysis. 367 (62.3%) patients had EF >40% which constituted HFiEF cohort while 222 (37.7%) patients with EF≤40% constituted HFrEF cohort. Using stepwise logistic regression, we identified preoperative EF (odds ratio [OR], 1.06; 95% confidence interval [CI], 1.02-1.11; P =0.006), left ventricular end-systolic diameter (OR, 0.93; 95% CI, 0.91-0.95; P =0.000) and history of myocardial infarction (OR, 0.61; 95% CI, 0.42-0.88; P =0.008) were associated with being in HFiEF group. Using Cox proportional hazard models, HFiEF patients had lower risk of all-cause mortality (hazard ratios [HR], 0.39; 95% CI, 0.23-0.68; P =0.001), sudden cardiac death (HR, 0.32; 95% CI, 0.14-0.75; P =0.009) and death due to HF (HR, 0.13; 95% CI, 0.03-0.52; P =0.004) compared to HFrEF patients. Nonproportional outcome of composite end points (i.e., combination of all-cause mortality, HF hospitalization and repeat revascularization) between HFiEF and HFrEF groups was detected by using the Schoenfeld residuals. By using flexible parametric model, patients with HFiEF had similar risk of composite end points in the first 5 years (HR, 0.84; 95% CI, 0.53-1.31; P =0.433), but significantly lower risk during years 6 to 11(HR, 0.12; 95% CI, 0.03-0.56; P =0.007). In the HFiEF group, the risk of death were age (HR, 1.07; 95% CI, 1.02-1.12; P =0.008), current smoking (HR, 5.62; 95% CI, 1.93-18.18; P =0.002) and history of myocardial infarction (HR, 2.89; 95% CI, 1.05-7.93; P =0.039). By contrast, in the HFrEF group, the risk factors were moderate or severe mitral regurgitation (HR, 1.81; 95% CI, 1.06-3.11; P =0.031) and estimated glomerular filtration rate (HR, 0.97; 95% CI, 0.95-0.99; P=0.014). Conclusions: Patients with ischemic HFiEF have distinct clinical characteristics and favorable outcomes. Our data support HFiEF as a distinct HF category in ischemic HF patients after revascularization therapy.
Exploring the safety, effect on the tumor microenvironment, and efficacy of itacitinib in combination with epacadostat or parsaclisib in advanced solid tumors: a phase I study
Naing, Aung , Powderly, John D. , Nemunaitis, John , Luke, Jason J. , Mansfield, Aaron S. , Messersmith, Wells A. , Sahebjam, Solmaz , LoRusso, Patricia , Garrido‐Laguna, Ignacio , Leopold, Lance, Geschwindt, Ryan, Ding, Kai , Smith, Michael , Nemunaitis, John J , Mansfield, Aaron S , Luke, Jason J , Berlin, Jordan D.

Journal for ImmunoTherapy of Cancer | March 14, 2022 | Volume: 10 | Issue: 3 | Pages: e004223

10.1136/jitc-2021-004223 | PMID 35288468 Get It

Background This phase I multicenter study was designed to evaluate the safety, tolerability, efficacy, and translational effects on the tumor microenvironment of itacitinib (Janus-associated kinase 1 (JAK1) inhibitor) in combination with epacadostat (indoleamine 2,3-dioxygenase 1 (IDO1) inhibitor) or parsaclisib (phosphatidylinositol 3-kinase δ (PI3Kδ) inhibitor). Methods Patients with advanced or metastatic solid tumors were enrolled and received itacitinib (100–400 mg once a day) plus epacadostat (50–300 mg two times per day; group A), or itacitinib (100–400 mg once a day) plus parsaclisib or parsaclisib monotherapy (0.3–10 mg once a day; group B). Results A total of 142 patients were enrolled in the study. The maximum tolerated dose was not reached for either the combination of itacitinib plus epacadostat (n=47) or itacitinib plus parsaclisib (n=90). One dose-limiting toxicity of serious, grade 3 aseptic meningitis was reported in a patient receiving itacitinib 300 mg once a day plus parsaclisib 10 mg once a day, which resolved when the study drugs were withdrawn. The most common treatment-related adverse events among patients treated with itacitinib plus epacadostat included fatigue, nausea, pyrexia, and vomiting, and for patients treated with itacitinib plus parsaclisib were fatigue, pyrexia, and diarrhea. In the itacitinib plus epacadostat group, no patient had an objective response. Among patients receiving itacitinib 100 mg once a day plus parsaclisib 0.3 mg once a day, three achieved partial response for an objective response rate (95% CI) of 7.1% (1.50 to 19.48). Treatment with itacitinib plus epacadostat demonstrated some increase in tumor CD8+ T cell infiltration and minor changes in six plasma proteins, whereas treatment with itacitinib plus high-dose parsaclisib resulted in downregulation of 20 plasma proteins mostly involved in immune cell function, with no observed change in intratumoral CD8+ T cell infiltration. Conclusion Adverse events with JAK1 inhibition combined with either IDO1 or PI3Kδ inhibition were manageable, but the combinations demonstrated limited clinical activity or enhancement of immune activation in the tumor microenvironment. Trial registration number NCT02559492.
Abstract GS4-07: The Breast PreCancer Atlas DCIS genomic signatures define biology and correlate with clinical outcomes: An analysis of TBCRC 038 and RAHBT cohorts
King, Lorraine , Simpson, Lunden , Khan, Aziz , Harmon, Bryan, Gallagher, Kristalyn K. , Kilgore, Mark , Wei, Shi, King, Tari A. , McAuliffe, Priscilla F. , Nangia, Julie R. , Lee, Joanna , Storniolo, Anna Maria , Thompson, Alastair M. , Burns, Robyn, Veis, Deborah J. , DeSchryver, Katherine, Matusiak, Magdalena , Wang, Jason, Tappenden, Jen, Ding, Daisy Yi , Zhang, Dadong , Jiang, Shu , Straub, Cody, Srivastava, Sucheta, Tibshirani, Rob , Angelo, Robert Michael, Owzar, Kouros , Polyak, Kornelia, Hwang, E. Shelley, Strand, Siri H. , Rivero‐Gutiérrez, Belén , Houlahan, Kathleen E. , Seoane, José Antonio , Risom, Tyler , Vennam, Sujay , Hardman, Timothy, Couch, Fergus J. , DeMichele, Angela , Tseng, Jennifer F. , Gupta, Gaorav P , Zhu, Chunfang , Zhu, Shirley , Luo, Jingqin , Varma, Sushama , Curtis, Christina , Angelo, Robert Michael, Hall, Allison , Polyák, Kornélia , Maley, Carlo C. , Marks, Jeffrey R. , Colditz, Graham A. , West, Robert B.

Cancer Research | March 8, 2022 | Volume: 82 | Issue: 4_Supplement | Pages: GS4-07-GS4-07

10.1158/1538-7445.sabcs21-gs4-07 Get It

Abstract Background. DCIS consists of a molecularly heterogeneous group of premalignant lesions, with variable risk of invasive progression. Understanding biomarkers for invasive progression could help individualize treatment recommendations based upon tumor biology. As part of the NCI Human Tumor Atlas Network (HTAN), we conducted comprehensive genomic analyses on two large DCIS case-control cohorts. Methods. We performed smart3-seq and low-pass whole genome sequencing on two independent, retrospective, longitudinally sampled DCIS case-control cohorts. TBCRC 038 was a multicenter cohort diagnosed with DCIS between 1998 and 2016 at one of the Translational Breast Cancer Research sites; the RAHBT (Resource of Archival Human Breast Tissue) cohort included women identified through the St. Louis Breast Tissue Repository, and the Women’s Health Repository diagnosed between 1997 and 2001. We studied the spectrum of molecular changes present and sought genomic predictors of subsequent ipsilateral breast events (iBEs: DCIS recurrence or invasive progression) in both DCIS epithelium and stroma in formalin fixed paraffin embedded tissue. We generated de novo tumor and stroma-centric subtypes for DCIS that represents fundamental transcriptomic organization. Copy number analysis was performed using low-pass DNA sequencing. Non-negative matrix factorization (NMF) was applied to the RNA expression of all coding genes to identify clusters. A negative-binomial regression model was used to identify differentially expressed genes. Results. We analyzed 677 DCIS samples from 481 patients with 7.1 years median follow-up. In TBCRC samples, we identified three clusters via NMF in TBCRC referred to as ER low, quiescent, and ER high. The ER-low cluster had significantly higher levels of ERBB2 and lower levels of ESR1 compared to quiescent and ER-high clusters. Quiescent cluster lesions were less proliferative and less metabolically active than ER high and ER low subtypes. These findings were replicated in the RAHBT cohort. Focusing on the stromal component of DCIS from laser capture microdissection in RAHBT samples, we identified four distinct DCIS-associated stromal clusters. A “normal-like” stromal cluster with ECM organization and PI3K-AKT signaling; a “collagen-rich” stromal cluster; a “desmoplastic” stromal cluster with high fibroblast and total myeloid abundance, mostly associated with macrophages and myeloid dendritic cells (mDC); and an “immune-dense” stromal cluster. Further, we compared differentially expressed genes in patients with or without subsequent iBEs within 5 years of diagnosis. Hypothesizing that the resulting 812 DE genes (DESeq2) represent multiple routes to subsequent iBEs, we leveraged NMF to identify paths to progression. In both TBCRC and RAHBT cohorts, poor outcome groups exhibited increased ER, MYC signaling, and oxidative phosphorylation, supporting that these pathways are important for DCIS recurrence and progression. Conclusion. Comprehensive genomic profiling in two independent DCIS cohorts with longitudinal outcomes shows distinct DCIS stromal expression patterns and immune cell composition. RNA expression profiles reveal underlying tumor biology that is associated with later iBEs in both cohorts. These studies provide new insight into DCIS biology and will guide the design of diagnostic strategies to prevent invasive progression. Citation Format: Siri H Strand, Belén Rivero-Gutiérrez, Kathleen E Houlahan, Jose A Seoane, Lorraine M King, Tyler Risom, Lunden Simpson, Sujay Vennam, Aziz Khan, Timothy Hardman, Bryan E Harmon, Fergus J Couch, Kristalyn Gallagher, Mark Kilgore, Shi Wei, Angela DeMichele, Tari King, Priscilla F McAuliffe, Julie Nangia, Joanna Lee, Jennifer Tseng, Anna Maria Storniolo, Alastair Thompson, Gaorav Gupta, Robyn Burns, Deborah J Veis, Katherine DeSchryver, Chunfang Zhu, Magdalena Matusiak, Jason Wang, Shirley X Zhu, Jen Tappenden, Daisy Yi Ding, Dadong Zhang, Jingqin Luo, Shu Jiang, Sushama Varma, Cody Straub, Sucheta Srivastava, Christina Curtis, Rob Tibshirani, Robert Michael Angelo, Allison Hall, Kouros Owzar, Kornelia Polyak, Carlo Maley, Jeffrey R Marks, Graham A Colditz, E Shelley Hwang, Robert B West. The Breast PreCancer Atlas DCIS genomic signatures define biology and correlate with clinical outcomes: An analysis of TBCRC 038 and RAHBT cohorts [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr GS4-07.
3-Aminophthalic acid, a new cereblon ligand for targeted protein degradation by O’PROTAC
Yan, Yuqian , Shao, Jingwei , Ding, Donglin , Pan, Yunqian , Tran, Phuc , Li, Hongyu , Huang, Haojie , Huang, Rui , Yan, Wei , Wang, Zhenyu

Chemical Communications | January 26, 2022 | Volume: 58 | Issue: 14 | Pages: 2383-2386

10.1039/d1cc06525d | PMID 35080528 Get It

In this study, we discovered 3-aminophthalic acid as a new ligand of cereblon (CRBN) E3 ubiquitin ligase and developed a phthalic acid-based O’PROTAC for ERG destruction, expanding the pool of ligands for development of PROTACs, especially O’PROTACs.
Pembrolizumab plus dinaciclib in patients with hematologic malignancies: the phase 1b KEYNOTE-155 study
Gregory, Gareth P. , Kumar, Shaji , Mahadevan, Daruka , Walker, Patricia , Wagner‐Johnston, Nina D. , Bannerji, Rajat , Bhutani, Divaya , Chang, Julie , Hernandez‐Ilizaliturri, Francisco J. , Klein, Andreas K. , Pagel, John M. , Rybka, Witold B. , Mohrbacher, Anne, Huang, Mo , Farooqui, Mohammed, Marinello, Patricia, Wagner-Johnston, Nina , Bannerji, Rajat , Bhutani, Divaya , Rybka, Witold , Yee, Andrew J , Huang, Mo , Quach, Hang , Wang, Ding , Escobar, Carolina, Mohrbacher, Ann M., Quach, Hang

Blood Advances | December 31, 2021 | Volume: 6 | Issue: 4 | Pages: 1232-1242

10.1182/bloodadvances.2021005872 | PMID 34972202 Get It

AbstractPreclinical data demonstrated that combining an anti–programmed cell death 1 (PD-1) inhibitor with a cyclin-dependent kinase 9 (CDK9) inhibitor provided enhanced antitumor activity with no significant toxicities, suggesting this combination may be a potential therapeutic option. The multicohort, phase 1 KEYNOTE-155 study evaluated the safety and antitumor activity of the PD-1 inhibitor pembrolizumab plus the CDK9 inhibitor dinaciclib in patients with relapsed or refractory (rr) chronic lymphocytic leukemia (CLL), diffuse large B-cell lymphoma (DLBCL) and multiple myeloma (MM). Patients enrolled were ≥18 years of age with a confirmed diagnosis of CLL, DLBCL, or MM. The study included 2 phases: a dose-evaluation phase to determine dose-limiting toxicities and a signal-detection phase. Patients received pembrolizumab 200 mg every 3 weeks plus dinaciclib 7 mg/m2 on day 1 and 10 mg/m2 on day 8 of cycle 1 and 14 mg/m2 on days 1 and 8 of cycles 2 and later. Primary endpoint was safety, and a key secondary endpoint was objective response rate (ORR). Seventy-two patients were enrolled and received ≥1 dose of study treatment (CLL, n = 17; DLBCL, n = 38; MM, n = 17). Pembrolizumab plus dinaciclib was generally well tolerated and produced no unexpected toxicities. The ORRs were 29.4% (5/17, rrCLL), 21.1% (8/38, rrDLBCL), and 0% (0/17, rrMM), respectively. At data cutoff, all 72 patients had discontinued treatment, 38 (52.8%) because of progressive disease. These findings demonstrate activity with combination pembrolizumab plus dinaciclib and suggest that a careful and comprehensive approach to explore anti–PD-1 and CDK9 inhibitor combinations is warranted. This trial was registered at www.clinicaltrials.gov as NCT02684617.
Inhibition of mTOR or MAPK ameliorates vmhcl/myh7 cardiomyopathy in zebrafish
Li, Jiarong , Zhu, Ping , Shih, Yu-Huan, Wang, Mingmin , Zhang, Yuji , Xu, Xiaolei , Bu, Haisong, Ding, Yonghe , Lin, Xueying , Wang, Mingmin , Bu, Haisong

JCI Insight | December 21, 2021 | Volume: 6 | Issue: 24 | Pages: No page available

10.1172/jci.insight.154215 | PMID 34935644 Get It

Myosin heavy chain 7 (MYH7) is a major causative gene for hypertrophic cardiomyopathy, but the affected signaling pathways and therapeutics remain elusive. In this research, we identified ventricle myosin heavy chain like ( vmhcl ) as a zebrafish homolog of human MYH7 , and we generated vmhcl frameshift mutants. We noted vmhcl -based embryonic cardiac dysfunction (VEC) in the vmhcl homozygous mutants and vmhcl -based adult cardiomyopathy (VAC) phenotypes in the vmhcl heterozygous mutants. Using the VEC model, we assessed 7 known cardiomyopathy signaling pathways pharmacologically and 11 candidate genes genetically via CRISPR/Cas9 genome editing technology based on microhomology-mediated end joining (MMEJ). Both studies converged on therapeutic benefits of mTOR or mitogen-activated protein kinase (MAPK) inhibition of VEC. While mTOR inhibition rescued the enlarged nuclear size of cardiomyocytes, MAPK inhibition restored the prolonged cell shape in the VEC model. The therapeutic effects of mTOR and MAPK inhibition were later validated in the VAC model. Together, vmhcl/myh7 loss of function is sufficient to induce cardiomyopathy in zebrafish. The VEC and VAC models in zebrafish are amenable to both efficient genetic and chemical genetic tools, offering a rapid in vivo platform for discovering candidate signaling pathways of MYH7 cardiomyopathy.
Building a precise machine-specific time structure of the spot and energy delivery model for a cyclotron-based proton therapy system
Zhao, Lewei , Zheng, Weili , Shen, Jiajian , Lee, Andrew , Yan, Di , Deraniyagala, Rohan, Stevens, Craig , Tang, Shikui, Ding, Xuanfeng , Shen, Jiajian , Liu, Gang , Li, Xiaoqiang

Physics in Medicine & Biology | December 14, 2021 | Volume: 67 | Issue: 1 | Pages: 01NT01

10.1088/1361-6560/ac431c | PMID 34905732 Get It

Abstract Objective . We proposed an experimental approach to build a precise machine-specific beam delivery time (BDT) prediction and delivery sequence model for standard, volumetric, and layer repainting delivery based on a cyclotron accelerator system. Approach . Test fields and clinical treatment plans’ log files were used to experimentally derive three main beam delivery parameters that impacted BDT: energy layer switching time (ELST), spot switching time, and spot drill time. This derived machine-specific model includes standard, volumetric, and layer repainting delivery sequences. A total of 103 clinical treatment fields were used to validate the model. Main results . The study found that ELST is not stochastic in this specific machine. Instead, it is actually the data transmission time or energy selection time, whichever takes longer. The validation showed that the accuracy of each component of the BDT matches well between machine log files and the model’s prediction. The average total BDT was about (−0.74 ± 3.33)% difference compared to the actual treatment log files, which is improved from the current commercial proton therapy system’s prediction (67.22%±26.19%). Significance . An accurate BDT prediction and delivery sequence model was established for an cyclotron-based proton therapy system IBA ProteusPLUS ® . Most institutions could adopt this method to build a machine-specific model for their own proton system.