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3499 citation(s) found for "Xu, Timothy".

An artificial intelligence model to detect abnormal ejection fraction from non-contrast chest computed tomography: the CT–LVEF study
Raikhelkar, J. , Richter, Ilan, Liu, Fengbei , Nizam, Nusrat Binta , Kishore, Varsha, vanMaanen, David, Ruhl, Jeffrey , Tesfuzigta, Naomi, Lancet, Erica, Leb, Jay , Legasto, Alan C. , Kumaraiah, Deepa, Prince, Martin, Sayer, G. , Uriel, Nir, Raikhelkar, Jayant , Ruhl, Jeffrey , Elias, Pierre , Poterucha, Timothy, Uriel, Nir , Bai, Zilong , Beecy, Ashley , Richter, Ilan, Kishore, Varsha, Kelsey, Chris R. , vanMaanen, David, Poterucha, Timothy Joseph , Prince, Martin, Wang, Fei , Estrin, Deborah L. , Sabuncu, Mert Rory

European Heart Journal - Digital Health | June 10, 2026 | Volume: 7 | Issue: 6 | Pages: No page available

10.1093/ehjdh/ztag088 | PMID 42388418 Get It

Abstract Aims Heart failure (HF), a major global health challenge, affects millions worldwide and poses substantial healthcare and economic burdens. It is estimated that a large proportion of those with early systolic dysfunction remain asymptomatic at a stage when guideline-directed medical therapies have been shown to prevent disease progression. To develop an artificial intelligence (AI) model capable of predicting abnormal left ventricular ejection fraction (EF) directly from static, non-gated, non-contrast chest computed tomography (CT) scans as a form of opportunistic screening, Methods and results Using a multi-institutional dataset of 34 058 paired non- contrast CT images and echocardiogram reports from two academic centres, we trained our model of classification for predicting left-ventricle ejection fraction (LVEF) categories: abnormal EF (EF < 50%) vs. normal on 25 948 studies. We validated the model on 8110 paired chest CT and echocardiogram results from a separate institution. The model achieved an area under the receiver operating characteristic (AUROC) curve of 0.786 on the hold-out test set and 0.762 on external validation to detect an abnormal EF (<50%). Beyond strong predictive performance, the AI model surpassed expert radiologists in both accuracy and efficiency and provided interpretable visualizations highlighting imaging features linked to reduced LVEF. Conclusion In this study, we developed and validated an AI model capable of predicting abnormal LVEF directly from static, non-gated, non-contrast chest CT scans, a novel application for an imaging modality typically used for unrelated indications as a form of opportunistic screening. This technology holds significant promise for early detection of systolic HF, reducing the diagnostic gap, and improving outcomes in asymptomatic HF patients.
Alpha DaRT source activity confirmation using a reentrant well‐type ionization chamber
Deufel, Christopher L. , Ordog, Jasmine L., Underwood, Kyle, Cohen, Yadin, Damato, Antonio L., Malouff, Timothy D., Underwood, James Kyle, Cohen, Gil’ad N. , Damato, Antonio L, Malouff, Timothy D.

Medical Physics | June 8, 2026 | Volume: 53 | Issue: 6 | Pages: No page available

10.1002/mp.70515 | PMID 42253233 Get It

Abstract Background Alpha‐emitting radionuclides enable precise cancer therapy through high linear energy transfer and limited tissue penetration, damaging tumor cells while sparing healthy tissue. Diffusing Alpha‐emitters Radiation Therapy (Alpha DaRT) features Ra‐224 sources that are implanted directly into the tumor and emit alpha particles during radioactive decay. Alpha DaRT has demonstrated efficacy and safety in preclinical and early clinical trials across multiple tumor types, including skin, head and neck, and pancreatic cancers. Purpose Reliable and efficient methods for verifying Alpha DaRT source activity prior to treatment can help support accurate and consistent radiation delivery. The direct measurement of alpha particles from sources within an Alpha DaRT applicator is impractical due to their short range; however, gamma emissions from the Ra‐224 sources can be used to infer radioactivity. This study established a protocol for verifying the source activity within Ra‐224 Alpha DaRT applicators using a reentrant well‐type ionization chamber, providing users with a practical method for detecting errors in source manufacturing or certificate paperwork without compromising applicator sterility. Methods Ra‐224 Alpha DaRT sources in sterile packaging (Flex and Needle applicators with 1–4 sources) were assessed. Source energy spectra and activities were verified using a high‐purity germanium (HPGe) radiation detector. Calibration factors (kBq/pA) were established using an IVB1000 well‐type ionization chamber with measurements conducted by placing single applicator sterile packages into the chamber with sources centered in the chamber's sweet spot and corrected for temperature, pressure, and leakage current. Quality assurance was performed on 26 Flex applicators using the established calibrations before the first clinical procedure. Results HPGe measurements agreed with vendor‐stated activities. The average calibration coefficient using the IVB1000 chamber was 233 ± 3 kBq/pA for Flex and 597 ± 7 kBq/pA for Needle applicators. Calibration coefficients were consistent across two IVB1000 chambers. Source number dependence was observed, with calibration factors increasing by 1.7% ± 0.7% per source (Needle) and 2.7% ± 0.6% per source (Flex). Measurement repeatability was 3.3%. Applying the calibration to 26 Flex applicators before the first patient treatment yielded a 1.1 ± 5.8% (range: −7.5% to 11.4%) difference relative to the vendor's stated activity. Conclusion A reentrant well‐type ionization chamber is suitable for pre‐treatment quality assurance of Ra‐224 Alpha DaRT applicators, enabling verification of the vendor‐stated activity while maintaining sterility within sealed packaging.
Executive summary of American Radium Society Appropriate Use Criteria for the treatment of locoregionally recurrent rectal cancer
Miller, Eric D. , Jethwa, Krishan R. , Dozois, E, Jin, Zhaohui, Abood, G., Akselrod, Dmitriy, Attallah, Joseph, Codipilly, D Chamil, Anker, Christopher J., Hallemeier, Christopher L. , Kennedy, Timothy, Lee, Percy, Ling, Diane C., Newman, Neil, Sharma, Navesh, Small, William, Tchelebi, Leila, Russo, Suzanne , Akselrod, Dmitriy , Dozois, Eric, Akselrod, Dmitriy , Small, William , Jethwa, Krishan , Dozois, Eric J. , Abood, Gerard, Codipilly, Don C. , Anker, Christopher J. , Hallemeier, Christopher Leigh , Hassett, Leslie C. , Lee, Percy, Newman, Neil B. , Tchelebi, Leila T.

Cancer | June 5, 2026 | Volume: 132 | Issue: 12 | Pages: No page available

10.1002/cncr.70464 | PMID 42246062 Get It

Abstract This literature‐based systematic review and associated guidelines provide evidence‐based paradigms for the management of locoregionally recurrent rectal cancer (LRRC). This multispecialty committee included gastrointestinal radiation and medical oncology, gastroenterology, radiology, and colorectal surgery. As is the standard, the previously described American Radium Society Appropriate Use Criteria methodology for this project was followed rigorously, with the Population, Intervention, Comparator, Outcome, Timing, and Study Design framework and Preferred Reporting Items for Systematic Reviews and Meta‐Analyses methodology to assess the evidence. RAND/University of California Los Angeles consensus methodology (modified Delphi) was used to rate the appropriateness of treatment options. Published between January 1, 2013, and July 16, 2025, 116 peer‐reviewed trials provided the evidence: 10 were well‐designed randomized phase 2/3 trials, 29 were moderately well designed trials that accounted for most common biases (matched cohort and phase 2), 76 trials had design limitations (retrospective), and one was a meta‐analysis. Clinical cases were created as examples to illustrate current acceptable management of LRRC. Treatment and prognosis are influenced by prior therapy and the site(s) and extent of LRRC. The ability to achieve a margin‐negative surgical resection is the ultimate determinant of survival and local control. Preoperative systemic therapy, radiation therapy, or a combination of the two can facilitate tumor downsizing and improve the likelihood of a margin‐negative resection. An individualized multidisciplinary approach is required to ensure the best outcome. Although this review does not suggest a major alteration of current practice, it provides reassuring evidence of the importance of combined‐modality therapy.
TRIPLETE But Incomplete? Accounting for Postprogression Therapy When Interpreting Overall Survival
Meimoun, Noah S. , Sherry, Alexander D. , Ludmir, Ethan B. , Lin, Timothy A. , Sherry, Alexander D , Ludmir, Ethan B , Lin, Timothy A

Journal of Clinical Oncology | June 4, 2026 | Volume: 44 | Issue: 23 | Pages: 2254-2255

10.1200/jco-26-00267 | PMID 42241666 Get It

Early results of COMPPARE, a prospective comparison of outcomes with proton and photon radiation in prostate cancer.
Mendenhall, Nancy P., Bryant, C. A., Katz, Aaron, Morris, Christopher G. , Crisp, Amy M., Odedina, Folakemi, Michalski, Jeff M., Slater, J.D., Choi, Seungtaek, Gayar, H., Sinesi, Christopher, Zlotecki, Robert A., Marshall, David T. , Waddle, Mark R. , Hoppe, Bradford, SHOWALTER, TIMOTHY, DiBiase, Steven J., Lee, W Robert, Chen, Ronald C., Lee, W. Robert , Mendenhall, Nancy P. , Bryant, Curtis, Katz, Aaron J., Crisp, Amy M , DeWees, T.A. , Michalski, Jeff M. , Choi, Seungtaek, Sinesi, Christopher, Showalter, Timothy N. , DiBiase, Steven J. , Chen, Ronald C.

Journal of Clinical Oncology | June 3, 2026 | Volume: 44 | Issue: 17_suppl | Pages: No page available

10.1200/jco.2026.44.17_suppl.lba5012 Get It

LBA5012 Background: There is a critical evidence gap on the relative benefits and harms of proton therapy (PT) compared with photon-based intensity-modulated radiation therapy (IMRT) in prostate cancer. Herein we report early results from COMPPARE, a non-randomized comparative study of outcomes with PT and IMRT in prostate cancer. Methods: Between 2018-2022, 2524 patients from 51 facilities (28 PT and 23 IMRT) enrolled in COMPPARE, including 1501 treated with PT and 1023 treated with IMRT, and were followed prospectively. Treatment naïve patients with localized prostate cancer except those with very high-risk disease were eligible. Treatment was pragmatic with daily standard fractionation (1.8-2.1 Gy) and moderate hypofractionation (2.4-3.1 Gy) permitted. Use of rectal spacers and androgen deprivation were at physician discretion. Patient-reported quality of life data and treatment team-reported toxicity and disease control outcomes were collected at baseline and pre-specified time intervals via VisionTreeOptimalCare; treatment planning and delivery data were collected via the Advanced Treatment Consortium. We analyzed 1404 PT patients and 939 IMRT patients. We report the early primary endpoint of the study, a comparison of patient reported bowel urgency and bowel frequency at 2-years using the EPIC tool, and the secondary endpoints of 2-year CTCAE v5 ≥ grade 2 gastrointestinal toxicity outcomes and 3-year freedom from biochemical progression (FFBP) results reported by the study teams. Results: Study sample size was targeted at 1,500 PT patients and 1,000 IMRT patients, and median follow-up time was 4.0 years. The primary endpoint and secondary toxicity 2-year endpoints focused on the alternative hypothesis of PT superiority. All results include inverse probability of treatment weighting. Using generalized linear mixed effects models, we found there to be no significant difference in EPIC bowel urgency scores (p = 0.324) or bowel frequency scores (p = 0.514) between PT and IMRT cohorts over time up to the 2-year endpoint. For grade 2 gastrointestinal toxicity, the 2-year cumulative incidence was 5.2% for PT and 5.6% for IMRT. Gray’s Test for competing risks showed a hazard ratio (HR) of 0.91 [95% confidence interval (CI): 0.65-1.28, p = 0.6] for PT versus IMRT. The exploratory non-inferiority endpoint of 3-year FFBP was 98.0% for PT and 97.9% for IMRT, and Gray’s Test showed a HR of 0.95 (95% CI: 0.52-1.71, p = 0.90). Conclusions: Analysis of early results of COMPPARE show no significant differences between PT and IMRT in patient reported bowel frequency and urgency, grade ≥2 gastrointestinal toxicity, or FFBP. Assessment of long-term disease control, late toxicity and secondary malignancy will require longer follow-up. Clinical trial information: NCT03561220 .
Indocyanine Green Fluorescence for Intraoperative Tumor Identification During Resection of Pediatric and Adolescent Intra-Abdominal Malignancy: A Prospective Multi-Institutional Observational Study
Schermerhorn, Sophia MV, Dasgupta, Roshni, Jenkins, Todd , Kastenberg, Zachary, Piché, Nelson , Roach, Jonathan P. , Rhee, Daniel S. , Tracy, Elisabeth T., Davies, Dafydd A., Boehmer, Chloé, Bondoc, Alexander , Tracy, Elisabeth T. , Polites, Stephanie F. , Tracy, Elisabeth T , Hartman, Stephen J. , Dasgupta, Roshni , Lautz, Timothy B. , Kastenberg, Zachary J. , Malek, Marcus M. , Aldrink, Jennifer H. , Brown, Erin G. , Lal, Dave R. , Kim, Eugene S. , Le, Hau D. , Boehmer, Chloé

Journal of the American College of Surgeons | June 3, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.1097/xcs.0000000000002056 | PMID 42233485 Get It

Background: Real-time intraoperative discrimination of malignant tissue during pediatric solid tumor resection is limited, constraining margin optimization; the utility of indocyanine green (ICG) fluorescence in this population remains incompletely defined. Study Design: Prospective, observational, multi-institutional study (2019–2023) of pediatric, adolescent, and young adult patients undergoing resection of intra-abdominal solid malignancies following preoperative ICG administration. The primary endpoint was diagnostic accuracy of ICG fluorescence for tumor-containing specimens; secondary endpoints included association with margin status and surgeon-perceived intraoperative benefit. Results: Forty-three operations in 42 patients yielded 55 specimens, of which 47 (85%) were malignant. Diagnostic performance was highest in hepatic tumors (sensitivity 83%, positive predictive value 83%) and lower in adrenal and heterogeneous tumor types. ICG avidity was not associated with improved negative margin rates (86% vs 75%, p=0.47). Surgeons reported intraoperative benefit in 67% of cases, most commonly improved visualization. No ICG-related adverse events occurred. Conclusions: ICG fluorescence provides reliable tumor identification in hepatic malignancies but does not correlate with margin-negative resection, indicating limited utility for margin guidance. These data support tumor-specific application and further investigation of optimized fluorescence strategies, including dosing, timing, and alternative fluorophores, in pediatric oncologic surgery.
A stereotactic laser interstitial thermal therapy strategy to flank dense calcifications within epileptogenic lesions: illustrative case
Neth, Bryan J., Lundstrom, Brian N., Kaufmann, Timothy J. , Miller, Kai, Neth, Bryan J. , Kaufmann, Timothy J , Miller, Kai J , Neth, Byran J. , Peña, Nicole M. De La , Lundstrom, Brian N. , Miller, Kai J.

Journal of Neurosurgery: Case Lessons | June 3, 2026 | Volume: 11 | Issue: 23 | Pages: No page available

10.3171/case26184 | PMID 42258890 Get It

BACKGROUND Laser interstitial thermal therapy is a minimally invasive surgical technique commonly used for treating epileptogenic foci in patients with drug-resistant epilepsy. Densely calcified lesions pose a challenge because they prevent the placement of a laser cannula within them and act as a heat shield. A 22-year-old male presented with intractable epilepsy with imaging demonstrating a densely calcified lesion in the right medial occipitotemporal gyrus radiographically consistent with a polymorphous low-grade neuroepithelial tumor of the young. OBSERVATIONS Two laser cannulas were stereotactically positioned to flank the centrally calcified portion of the lesion at its anterior and posterior aspects. Intraoperative MR thermography during each ablation showed that the dense calcification shielded ablative heating from spreading to the other side of the lesion. The sum of the thermal ablation zones covered the entirety of the lesion. Postprocedure MRI demonstrated overlapping peripherally enhancing ablation zones, which subsumed the entirety of the calcified mass. The patient tolerated the procedure well and remained seizure free at the 14-month follow-up. LESSONS Using multiple stereotactically placed laser filaments to flank epileptogenic lesions that are densely calcified is a strategy to effectively encompass the entirety of the lesion within the combined ablation zones. https://thejns.org/doi/10.3171/CASE26184
Functional Characterization of Myeloid Neoplasm-associated DDX41 Variants Reveals Pathogenic Interaction with Acquired Hotspot Mutation
Fisher, Julianna, Stepanchick, Emily , Wilson, Andrew, 潤一郎, 木田, Adam, Mike , Otero, Mariela V. Perez, Badar, Talha, Kusne, Yael, Ferrer, Alejandro, Patnaik, Mrinal M., Kida, Jun‐ichiro , Badar, Talha , Kusne, Yael , Ferrer, Alejandro , Patnaik, Mrinal M. , Chlon, Timothy M.

No container title available | June 1, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.64898/2026.05.27.727893 Get It

Abstract Germline variants in DDX41 are the most frequent genetic predisposition to adult hematologic malignancies. The most common variants are truncating, implicating loss of function in the pathogenesis. However, non-truncating variants account for 30-40% of cases, and their impact on essential DDX41 functions remains unknown. We utilized a genetic complementation assay to assess the functionality of 10 recurrent germline non-truncating variants of DDX41. All variants restored viability to Ddx41 -deficient hematopoietic progenitor cells at exogenous expression levels. In contrast, the hotspot mutant p.R525H, which is somatically acquired at disease onset in >50% of patients, failed to restore viability. CRISPR-based modeling in cell lines and mice revealed heterogeneity: some variants were non-functional at endogenous expression levels whereas others maintained complete functionality, supporting normal cell proliferation and even lifelong hematopoiesis in a homozygous setting. Notably, co-expression of p.R525H with some variants caused impaired hematopoietic progenitor cell viability, indicating a dominant-negative effect of p.R525H. In contrast, other variants, all classified as variants of unknown significance, were unaffected by the presence of p.R525H. A screen of 100 disease-associated variants confirmed that many non-truncating germline variants are susceptible to p.R525H-mediated dominant-negative effects, whereas wild-type DDX41 is not. These findings indicate that DDX41 variant curation is complicated by variable effects on functionality and variant-specific interactions with somatically-acquired DDX41 mutations. The dominant-negative effect of p.R525H provides a mechanistic basis for the conclusion of recent patient cohort analyses that co-occurrence with a somatic hotspot mutation is a reliable indicator of DDX41-driven disease in carriers of non-truncating variants.
Embracing technology to improve peripheral intravenous access and care: A consensus statement from vascular access experts and patients
Spencer, Timothy R. , Strain, Barbara, Hadaway, Lynn, Schears, Gregory, Steere, Lee, Hopkins, Thomas, Weathers, Elizabeth , Hadaway, Lynn

The Journal of Vascular Access | May 29, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.1177/11297298261451300 | PMID 42210772 Get It

Background/objectives: To develop expert consensus on peripheral venous access devices (PVAD) and associated care practices, and to formulate guidance recommendations aimed at improving peripheral venous access and management, including the integration of vein visualization technology. This is particularly important for patient populations with peripheral venous depletion, who often present with compromised vasculature that complicates successful PVAD access and increases the risk of complications. Preserving vascular integrity in these patients is essential for maintaining treatment pathways and preventing long-term vascular damage. Methods: A multi-phase approach to consensus development was used consisting of the following: (1) a literature review, (2) a survey and consultation with a vascular access expert panel ( n = 9), and (3) a consultation meeting with patient and public representatives ( n = 2). Results: Survey results and consultation findings from the expert panel demonstrated consensus for 14 of 24 statements. Further analysis resulted in a total of four key problem statements on peripheral venous access and care, and 11 recommendations for future development. Following review by patient and public representatives, three additional recommendations were added, and three existing recommendations were refined. The final consensus statement reflects four problem statements with 14 recommendations. Conclusion: This expert consensus presents 14 evidence-informed statements designed to strengthen practice, improve patient safety, and enhance clinician confidence and competence. Central to these recommendations is the adoption of routine structured pre-insertion vessel assessment using vein visualization technology where appropriate to minimize vessel trauma, and promote more consistent, high-quality vascular access care.