A thoracic surgery clinic dedicated to indeterminate pulmonary nodules: Too many scans and too little pathology?

ObjectiveWidespread application of computed tomographic scans has increased detection of asymptomatic pulmonary nodules. A dedicated clinic was established to encourage referral and manage large numbers of patients with such nodules.MethodsPatients were evaluated periodically by a nurse practitioner with surgeon oversight, and follow-up imaging was centralized. Patients were rescanned at intervals on the basis of radiologist recommendation.ResultsA total of 414 patients, 189 male and 225 female with a median age of 60.2 years (20.7–84.1 years), were evaluated since April 2000. Median follow-up was 1.51 years (0–6.65 years). Thirty-seven percent (153/414) were older than 60 years with at least 10 pack-years of tobacco use, whereas 30% (123/414) had never smoked. A total of 286 patients completed at least 2 years of follow-up computed tomographic evaluation. After 2 years, 24.2% (69/286) were deemed in stable condition and were discharged from further follow-up, whereas 22.4% (64/286) of patients were followed up longer than 2 years owing to the development of new nodules. Forty-five percent (127/286) of patients did not complete their recommended follow-up at our clinic. Overall, 3% (13/414) of our patients have been shown to have a malignant tumor. Only 5 patients underwent curative resection of a primary lung cancer.ConclusionIn a population of patients with indeterminate nodules in routine clinical practice, few patients required intervention and few cancers were detected. Although the benefits of a “nodule” clinic may include patient reassurance and convenience to referring physicians, a significant number of patients did not complete their follow-up in our clinic

Quantitative Computed Tomography in COPD: Possibilities and Limitations

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease that is characterized by chronic airflow limitation. Unraveling of this heterogeneity is challenging but important, because it might enable more accurate diagnosis and treatment. Because spirometry cannot distinguish between the different contributing pathways of airflow limitation, and visual scoring is time-consuming and prone to observer variability, other techniques are sought to start this phenotyping process. Quantitative computed tomography (CT) is a promising technique, because current CT technology is able to quantify emphysema, air trapping, and large airway wall dimensions. This review focuses on CT quantification techniques of COPD disease components and their current status and role in phenotyping COPD

Pynta - An automated workflow for calculation of surface and gas-surface kinetics

Many important industrial processes rely on heterogeneous catalytic systems. However, given all possible catalysts and conditions of interest it is impractical to optimize most systems experimentally. Automatically generated microkinetic models can be used to efficiently consider many catalysts and conditions. However, these microkinetic models require accurate estimation of many thermochemical and kinetic parameters. Manually calculating these parameters is tedious and error prone involving many interconnected computations. We present Pynta, a workflow software for automating the calculation of surface and gas-surface reactions. Pynta takes the reactants, products and atom maps for the reactions of interest, generates sets of initial guesses for all species and saddle points, runs all optimizations, frequency, and IRC calculations and computes the associated thermochemistry and rate coefficients. It is able to consider all unique adsorption configurations for both adsorbates and saddle points allowing it to handle high index surfaces and bidentate species. Pynta implements a new saddle point guess generation method called harmonically forced saddle point searching (HFSP). HFSP defines harmonic potentials based on the optimized adsorbate geometries and which bonds are breaking and forming that allow initial placements to be optimized using the GFN1-xTB semiempirical method to create reliable saddle point guesses. This method is reaction class agnostic and fast, allowing Pynta to consider all possible adsorbate site placements efficiently. We demonstrate Pynta on 11 diverse reactions involving monodenate, bidentate and gas-phase species, many distinct reaction classes and both a low and a high index facet of Cu. Our results suggest that it is very important to consider reactions between adsorbates adsorbed in all unique configurations for inter-adsorbate group transfers and reactions on high index surfaces