Computational fluid dynamics modeling of coronary artery blood flow using OpenFOAM: Validation with the food and drug administration benchmark nozzle model.

Cardiovascular disease (CVD), a global health concern, particularly coronary artery disease (CAD), poses a significant threat to well-being. Seeking safer and cost-effective diagnostic alternatives to invasive coronary angiography, noninvasive coronary computed tomography angiography (CCTA) gains prominence. This study employed OpenFOAM, an open-source Computational Fluid Dynamics (CFD) software, to analyze hemodynamic parameters in coronary arteries with serial stenoses. Patient-specific three-dimensional (3D) models from CCTA images offer insights into hemodynamic changes. OpenFOAM breaks away from traditional commercial software, validated against the FDA benchmark nozzle model for reliability. Applying this refined methodology to seventeen coronary arteries across nine patients, the study evaluates parameters like fractional flow reserve computed tomography simulation (FFRCTS), fluid velocity, and wall shear stress (WSS) over time. Findings include FFRCTS values exceeding 0.8 for grade 0 stenosis and falling below 0.5 for grade 5 stenosis. Central velocity remains nearly constant for grade 1 stenosis but increases 3.4-fold for grade 5 stenosis. This research innovates by utilizing OpenFOAM, departing from previous reliance on commercial software. Combining qualitative stenosis grading with quantitative FFRCTS and velocity measurements offers a more comprehensive assessment of coronary artery conditions. The study introduces 3D renderings of wall shear stress distribution across stenosis grades, providing an intuitive visualization of hemodynamic changes for valuable insights into coronary stenosis diagnosis.

High vs. Standard Radiotherapy Dose in Locally Advanced Rectal Adenocarcinoma Patients Treated With Neoadjuvant Long Course Chemoradiotherapy: A Population-based Study.

BACKGROUND/AIM: Locally advanced rectal cancer (LARC) patients are often treated with neoadjuvant long course chemoradiotherapy (NLCCRT) using 45-50.4 Gy conventional fractionated radiotherapy (CFRT). The role of radiotherapy dose escalation is unclear. PATIENTS AND METHODS: We identified LARC patients diagnosed from 2011 to 2016 and treated with NLCCRT using CFRT at high dose (54-60 Gy) or standard dose (45-50.4 Gy). In the primary analyses, we used propensity score (PS) weighting to balance the observable potential confounders. The hazard ratio (HR) of death and other endpoints were compared. We also evaluated these outcomes in supplementary analyses via an alternative approach. RESULTS: Our primary analysis included 459 patients. The HR of death when high dose was compared with standard dose was 0.62 (p=0.51). There were also no statistically significant differences in other endpoints or in the supplementary analyses. CONCLUSION: Overall, survival of LARC patients treated with NLCCT in CFRT was not significantly different between high or standard dose.

Effectiveness of Image-Guided Radiotherapy in Adjuvant Radiotherapy on Survival for Localized Breast Cancer: A Population-Based Analysis.

PURPOSE: Image-guided radiotherapy (IGRT) is an advanced radiotherapy technique to improve the radiotherapy delivery. We aimed to compare the overall survival (OS) for localized breast cancer (LBC) patient treated with adjuvant conventional fractionated radiotherapy (CFRT) using IGRT vs those without IGRT via a population-based analysis. PATIENTS AND METHODS: Eligible LBC patients diagnosed between 2011 and 2013 were identified via the Taiwan Cancer Registry. We used propensity score (PS) weighting to balance observable potential confounders between groups. The hazard ratio (HR) of death and other outcomes were compared between IGRT and non-IGRT. We also evaluated OS in various supplementary analyses. RESULTS: Our primary analysis included 6490 patients in whom covariates were well balanced after PS weighing. The HR for death when IGRT was compared with non-IGRT was 1.02 (95% confidence interval 0.80-1.31, P = 0.86). There were also no significant differences in the supplementary analyses. CONCLUSION: We found that OS of LBC patients treated with adjuvant CFRT was not statistically different between those treated with IGRT versus without IGRT. This was the first study in this regard to our knowledge but randomized controlled trials were needed to confirm our finding.