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A variety of three-dimensional (3D) printing techniques and materials facilitate the creation of customized models that promise to improve surgical procedures and patient outcomes. Three-dimensional-printed models allow patients, trainees, and experienced surgeons to explore anatomy through direct visualization and tactile feedback. Although 3D-printed models serve a range of purposes including preoperative planning, education, skills refinement, patient-specific intraprocedural guides, and implants, much work remains to decrease the turnaround time and cost of printing models, collect long-term effectiveness data, and refine regulatory oversight of 3D printing in medicine.

Natalie S. Lui

Online educational modules can augment radiology learning by creating opportunities to interact with images in more dynamic ways than with static presentation of images in lectures or journal articles. Building these modules on an online survey platform allows for quantitative assessment and learner feedback, without requiring programming knowledge or need for new website creation.Interactive online tutorials were built on a web-based survey platform (Qualtrics, Provo, Utah) accessible by computer or mobile device to teach radiology imaging findings of selected high-morbidity diagnoses. Topics included congenital-type internal hernias (module 1), acute appendicitis in the pregnant patient (module 2), and unintentionally retained surgical instruments (RSI; module 3). Modules consisted of pretest, educational module, and post-test components. For modules 1 and 2, graphics interchange formats were utilized to show CT and MRI image stacks for the diagnosis of congenital-type internal hernias and acute appendicitis in pregnant patients, respectively. For module 3, the "Heat Map" format was chosen to showcase intraoperative radiograph cases, which allowed participants to click on the potential RSI in the image. Pre- and post-test scores were evaluated. To determine statistical significance, an alpha level of 0.05 was utilized.Module 1 (Internal Hernia): Twenty-one radiology trainees completed the module. The mean pretest score was 3.66 (±1.13) points out of a total 6 possible points (61%), compared to 4.52 (±1.03) points on the post-test (75%). This was a statistically significant increase on the post-test of 0.87 points (95% CI [confidence interval] 0.36, 1.38), t(20) = 3.53, p= 0.002. Module 2 (MR Appendicitis): Seventeen radiology trainees completed the module. The mean pretest score was 3.18 (±1.42) points out of a total 6 possible points (53%), compared to 5.12 (±0.86) points on the post-test (85%). This was a statistically significant increase on the post-test of 1.94 points (95% CI 1.12, 2.76), t(16) = 5.00, p0.001. Module 3 (RSI): One hundred seven participants completed the module. The mean pretest score was 3.60 (±1.53) points out of a total 6 possible points (60%), compared to 4.54 (±1.36) points on the post-test (76%). This was a statistically significant increase on the post-test of 0.94 points (95% CI 0.67, 1.21), t(106) = 6.84, p0.001.An online survey platform can be used to build interactive education modules. Post-test scores significantly improved from pretest scores with these educational modules.

We describe the creation and characterization of a calibration CT mini‐lung‐phantom incorporating simulated airways and ground‐glass densities. Ten duplicate mini‐lung‐phantoms with Three‐Dimensional (3‐D) printed tubes simulating airways and gradated density polyurethane foam blocks were designed and built. Dimensional accuracy and CT numbers were measured using micro‐CT and clinical CT scanners. Micro‐CT images of airway tubes demonstrated an average dimensional variation of 0.038 mm from nominal values. The five different densities of incorporated foam blocks, simulating ground‐glass, showed mean CT numbers (±standard deviation) of −897.0 ± 1.5, −844.1 ± 1.5, −774.1 ± 2.6, −695.3 ± 1.6, and −351.0 ± 3.7 HU, respectively. Three‐Dimensional printing and subtractive manufacturing enabled rapid, cost‐effective production of ground‐truth calibration mini‐lung‐phantoms with low inter‐sample variation that can be scanned simultaneously with the patient undergoing lung quantitative CT.

This cohort study examines the latest expansion of the lung cancer screening eligibility criteria for adults in the US., Key Points Question Is the updated US Preventive Services Task Force (USPSTF) recommendations for lung cancer screening associated with a clinically meaningful change in the distribution of the characteristics of individuals who are eligible for screening? Findings In this cohort study using data derived from 5 health care systems, the updated 2021 USPSTF recommendations were associated with an increased overall proportion of women, racial and ethnic minority groups, and individuals with lower socioeconomic status who are eligible for lung cancer screening. Meaning The 2021 USPSTF recommendations for lung cancer screening eligibility are expected to enhance opportunities for community-based programs to reduce barriers to lung cancer screening access for individuals who are at highest risk for lung cancer., Importance The US Preventive Services Task Force (USPSTF) released updated lung cancer screening recommendations in 2021, lowering the screening age from 55 to 50 years and smoking history from 30 to 20 pack-years. These changes are expected to expand screening access to women and racial and ethnic minority groups. Objective To estimate the population-level changes associated with the 2021 USPSTF expansion of lung cancer screening eligibility by sex, race and ethnicity, sociodemographic factors, and comorbidities in 5 community-based health care systems. Design, Setting, and Participants This cohort study analyzed data of patients who received care from any of 5 community-based health care systems (which are members of the Population-based Research to Optimize the Screening Process Lung Consortium, a collaboration that conducts research to better understand how to improve the cancer screening processes in community health care settings) from January 1, 2010, through September 30, 2019. Individuals who had complete smoking history and were engaged with the health care system for 12 or more continuous months were included. Those who had never smoked or who had unknown smoking history were excluded. Exposures Electronic health record–derived age, sex, race and ethnicity, socioeconomic status (SES), comorbidities, and smoking history. Main Outcomes and Measures Differences in the proportion of the newly eligible population by age, sex, race and ethnicity, Charlson Comorbidity Index, chronic obstructive pulmonary disease diagnosis, and SES as well as lung cancer diagnoses under the 2013 recommendations vs the expected cases under the 2021 recommendations were evaluated using χ2 tests. Results As of September 2019, there were 341 163 individuals aged 50 to 80 years who currently or previously smoked. Among these, 34 528 had electronic health record data that captured pack-year and quit-date information and were eligible for lung cancer screening according to the 2013 USPSTF recommendations. The 2021 USPSTF recommendations expanded screening eligibility to 18 533 individuals, representing a 53.7% increase. Compared with the 2013 cohort, the newly eligible 2021 population included 5833 individuals (31.5%) aged 50 to 54 years, a larger proportion of women (52.0% [n = 9631]), and more racial or ethnic minority groups. The relative increases in the proportion of newly eligible individuals were 60.6% for Asian, Native Hawaiian, or Pacific Islander; 67.4% for Hispanic; 69.7% for non-Hispanic Black; and 49.0% for non-Hispanic White groups. The relative increase for women was 13.8% higher than for men (61.2% vs 47.4%), and those with a lower comorbidity burden and lower SES had higher relative increases (eg, 68.7% for a Charlson Comorbidity Index score of 0; 61.1% for lowest SES). The 2021 recommendations were associated with an estimated 30% increase in incident lung cancer diagnoses compared with the 2013 recommendations. Conclusions and Relevance This cohort study suggests that, in diverse health care systems, adopting the 2021 USPSTF recommendations will increase the number of women, racial and ethnic minority groups, and individuals with lower SES who are eligible for lung cancer screening, thus helping to minimize the barriers to screening access for individuals with high risk for lung cancer.

PURPOSE: The purpose of this study was to develop a 3-dimensional (3D) printing method to create computed tomography (CT) realistic phantoms of lung cancer nodules and lung parenchymal disease from clinical CT images. MATERIALS AND METHODS: Low-density paper was used as substrate material for inkjet printing with potassium iodide solution to reproduce phantoms that mimic the CT attenuation of lung parenchyma. The relationship between grayscale values and the corresponding CT numbers of prints was first established through the derivation of exponential fitted equation from scanning data. Next, chest CTs from patients with early-stage lung cancer and coronavirus disease 2019 (COVID-19) pneumonia were chosen for 3D printing. CT images of original lung nodule and the 3D-printed nodule phantom were compared based on pixel-to-pixel correlation and radiomic features. RESULTS: CT images of part-solid lung cancer and 3D-printed nodule phantom showed both high visual similarity and quantitative correlation. R2 values from linear regressions of pixel-to-pixel correlations between 5 sets of patient and 3D-printed image pairs were 0.92, 0.94, 0.86, 0.85, and 0.83, respectively. Comparison of radiomic measures between clinical CT and printed models demonstrated 6.1% median difference, with 25th and 75th percentile range at 2.4% and 15.2% absolute difference, respectively. The densities and parenchymal morphologies from COVID-19 pneumonia CT images were well reproduced in the 3D-printed phantom scans. CONCLUSION: The 3D printing method presented in this work facilitates creation of CT-realistic reproductions of lung cancer and parenchymal disease from individual patient scans with microbiological and pathology confirmation.

BACKGROUND There is intense interest and speculation in the application of artificial intelligence (AI) to radiology. The goals of this investigation were (1) to assess thoracic radiologists' perspectives on the role and expected impact of AI in radiology, and (2) to compare radiologists' perspectives with those of computer science (CS) experts working in the AI development. METHODS An online survey was developed and distributed to chest radiologists and CS experts at leading academic centers and societies, comparing their expectations of AI's influence on radiologists' jobs, job satisfaction, salary, and role in society. RESULTS A total of 95 radiologists and 45 computer scientists responded. Computer scientists reported having read more scientific journal articles on AI/machine learning in the past year than radiologists (mean [95% confidence interval]=17.1 [9.01-25.2] vs. 7.3 [4.7-9.9], P=0.0047). The impact of AI in radiology is expected to be high, with 57.8% and 73.3% of computer scientists and 31.6% and 61.1% of chest radiologists predicting radiologists' job will be dramatically different in 5 to 10 years, and 10 to 20 years, respectively. Although very few practitioners in both fields expect radiologists to become obsolete, with 0% expecting radiologist obsolescence in 5 years, in the long run, significantly more computer scientists (15.6%) predict radiologist obsolescence in 10 to 20 years, as compared with 3.2% of radiologists reporting the same (P=0.0128). Overall, both chest radiologists and computer scientists are optimistic about the future of AI in radiology, with large majorities expecting radiologists' job satisfaction to increase or stay the same (89.5% of radiologists vs. 86.7% of CS experts, P=0.7767), radiologists' salaries to increase or stay the same (83.2% of radiologists vs. 73.4% of CS experts, P=0.1827), and the role of radiologists in society to improve or stay the same (88.4% vs. 86.7%, P=0.7857). CONCLUSIONS Thoracic radiologists and CS experts are generally positive on the impact of AI in radiology. However, a larger percentage, but still small minority, of computer scientists predict radiologist obsolescence in 10 to 20 years. As the future of AI in radiology unfolds, this study presents a historical timestamp of which group of experts' perceptions were closer to eventual reality.

We present a case of a 69-year-old man who underwent tracheobronchoplasty for tracheobronchomalacia using a single-lumen endotracheal tube and a Y-shaped bronchial blocker for airway management. Tracheobronchoplasty is performed by sewing mesh to plicate the posterior, membranous wall of the distal trachea and main bronchi through a right posterolateral thoracotomy. The goals of airway management include continuous left-lung ventilation and lung protection from aspiration. Ideally, only conventional airway management tools are used. This case demonstrates that a single-lumen endotracheal tube with a bronchial blocker can be a straightforward strategy for airway management during tracheobronchoplasty.

Background: Cardiac fluorodeoxyglucose positron-emission tomography (FDG-PET) has emerged as a standard imaging modality for the diagnosis of cardiac sarcoidosis (CS); however, there is a scarcity of data on the use of serial FDG-PET to guide immunosuppressive therapy. The aim of this work was to report our experience using serial FDG-PET for the diagnosis and management of patients with CS, focusing on its utility in ongoing immunosuppression management. Methods and Results: We studied consecutive patients with CS managed at Stanford University from 2010 to 2017. We evaluated our experience using FDG-PET for diagnosis and guidance of immunosuppressive therapy titration in CS. Among 34 patients diagnosed with CS, 16 (47%), 12 (35%) and 14(41%) presented with heart block, heart failure, and ventricular arrhythmias, respectively. FDG-PET proved beneficial in the initial diagnosis in 21 patients (62%). A total of 128 FDG-PET scans were performed (median 3 per patient). Ninety-four FDG-PET scans (73%) resulted in a change in therapy, with 42FDG-PET scans (33%) instrumental for tapering prednisone. Among patients who were initiated on prednisone, the mean dose of prednisone at 1 year was 9.5mg/d. Over a median follow-up of 2.3years, 48% of patients were successfully weaned from prednisone completely, and 20% were weaned to a maintenance dosage of 5–10mg/d. During the follow-up period, transplant-free survival was 88%. Conclusions: The use of serial cardiac FDG-PET for the diagnosis and management of CS was critical for guiding immunosuppression management and resulted in low chronic steroid doses and good disease control within 1 year of diagnosis.

Purpose Computed tomography (CT) findings of bronchiolitis obliterans syndrome (BOS) can be nonspecific and variable. This study aims to measure the incremental value of automated quantitative lung CT analysis to clinical CT interpretation. A head-to-head comparison of quantitative CT lung density analysis by parametric response mapping (PRM) with qualitative radiologist performance in BOS diagnosis was performed. Materials and methods Inspiratory and end-expiratory CTs of 65 patients referred to a post-bone marrow transplant lung graft-versus-host-disease clinic were reviewed by 3 thoracic radiologists for the presence of mosaic attenuation, centrilobular opacities, airways dilation, and bronchial wall thickening. Radiologists' majority consensus diagnosis of BOS was compared with automated PRM air trapping quantification and to the gold-standard diagnosis of BOS as per National Institutes of Health (NIH) consensus criteria. Results Using a previously established threshold of 28% air trapping on PRM, the diagnostic performance for BOS was as follows: sensitivity 56% and specificity 94% (area under the receiver operator curve [AUC]=0.75). Radiologist review of inspiratory CT images alone resulted in a sensitivity of 80% and a specificity of 69% (AUC=0.74). When radiologists assessed both inspiratory and end-expiratory CT images in combination, the sensitivity was 92% and the specificity was 59% (AUC=0.75). The highest performance was observed when the quantitative PRM report was reviewed alongside inspiratory and end-expiratory CT images, with a sensitivity of 92% and a specificity of 73% (AUC=0.83). Conclusions In the CT diagnosis of BOS, qualitative expert radiologist interpretation was noninferior to quantitative PRM. The highest level of diagnostic performance was achieved by the combination of quantitative PRM measurements with qualitative image feature assessments.

We set to identify prognostic factors in a retrospective cohort of consecutive patients with stage I-II diffuse large B-cell lymphoma treated with rituximab-chemotherapy with or without radiotherapy from 2001 through 2017 at our institution. We identified 143 patients with median follow-up of 7.7 years. The majority were male (59.4%), had stage II (53.1%), had stage-modified IPI 0-1 (smIPI, 58.1%), and had non-bulky disease (7 cm, 68.5%). 99 patients (69.2%) received rituximab-chemotherapy followed by radiotherapy, and 44 patients (30.8%) received rituximab-chemotherapy alone. The 5-year progression-free survival (PFS) and overall survival (OS) were 81.2% and 88.9%, respectively. The 5-year PFS for those with smIPI 0-1 versus 2-4 was 89.5% versus 69.7%, respectively (

The morphometry of the large conducting airways is presumed to have a strong effect on the regional deposition of inhaled aerosol particles. Nevertheless, sex-based differences have not been fully quantified and are still largely ignored in designing inhalation therapies. To this end, we retrospectively analyzed high-resolution computed tomography scans for 185 individuals (90 women, 95 men) in the age range of 12-89 yr to determine airway luminal areas, airway lengths, and bifurcation angles. Only subjects free of chronic airway disease were considered. In men, luminal areas of the upper conducting airways were, on average, ∼30%-50% larger when compared with those in women, with the largest differences found in the trachea (289.72 ± 54.25 vs. 193.50 ± 42.37 mm2 for men and women, respectively). The ratio of the largest luminal area in men to the smallest luminal area in women (in any given segment) ranged between 4.5 and 8.6, the largest differences being found in the lobar bronchi. Sex-based differences were minor in the case of bifurcation angles (e.g., average main bifurcation angle: 93.04 ± 9.58° vs. 91.03 ± 9.81° for men and women, respectively), but large intersubject variability was found irrespective of sex (e.g., range of main bifurcation angle: 65.04°-122.01° vs. 69.46°-113.94° for men and women, respectively). Bronchial segments were shorter by ∼5%-20% in women relative to men, the largest differences being located in the upper lobes. False discovery rate analysis revealed statistically significant associations among morphometric measures of the right lung in women (but not in men), suggesting two phenotypes among women that we attribute to the smaller female thoracic volume.NEW & NOTEWORTHY We found significant sex-based morphometric differences in the central airways of healthy men and women that were only mildly attenuated in subsets matched for lung volume. Lumen areas were significantly larger in men (∼30%-50%). Large variability (∼75%-87%) in airway bifurcation angles (60°-122°) was found irrespective of sex. The branching pattern of the right main and right upper bronchi in women (but not in men) follows two phenotypes modulated by lung volume.

Increasing evidence suggests that consolidation durvalumab confers limited benefits for patients with stage III EGFR-mutated NSCLC. Induction or maintenance EGFR tyrosine kinase inhibitors (TKIs) added to concurrent chemoradiotherapy (CRT) may optimize definitive treatment, but there are limited data supporting an induction TKI strategy.We evaluated the efficacy and safety of induction EGFR TKIs administered before concurrent CRT in a retrospective series of patients with unresectable locally advanced EGFR-mutated NSCLC. Circulating tumor DNA (ctDNA) analysis was performed on a patient subset using CAPP-seq and correlated with outcomes.Of six patients, three received erlotinib and three osimertinib as induction therapy before CRT. Induction TKIs were administered for a median of 2.5 months. The objective response rate after induction TKI was 83%. One patient had a complete response to induction erlotinib and continued erlotinib for 4 years until local progression, which was treated with CRT. Two patients completed maintenance erlotinib after CRT, and another received consolidation durvalumab. After a median follow-up of 20.5 months, only one patient developed disease recurrence, with rising ctDNA coinciding with recurrence. ctDNA remained undetectable in patients without recurrence, or low-level in a patient receiving maintenance erlotinib. Adverse events were mild and expected, and none developed pneumonitis.Induction EGFR TKI before CRT may achieve high disease control rates with promising signs of durability in patients with locally advanced EGFR-mutated NSCLC. ctDNA analysis after CRT can correlate well with clinical outcomes. Prospective studies are needed to define the role of induction EGFR TKIs in this setting.

When a patient is found to have multiple lung tumors, distinguishing whether they represent metastatic nodules or separate primary cancers is crucial for staging and therapy. We report the case of a 79-year-old patient with two surgically resected synchronous left upper lobe adenocarcinomas initially pathologically staged as T3 (IIB), indicating adjuvant chemotherapy should be recommended. However, the tumors appeared radiographically distinct, so next-generation sequencing was performed on each nodule. Each tumor harbored a different mesenchymal-to-epithelial transition (MET) exon 14 skipping mutation, an emerging targetable mutation, suggestive of distinct clonality. While the in frame protein deletion was the same in each tumor, the nucleotide base substitutions were different. Thus, the patient was down-staged to having two separate IA tumors, spared of adjuvant chemotherapy, and routine surveillance was recommended. This case highlights the utility of using molecular analysis in diagnosing and treating multifocal lung tumors, and the process of convergent molecular evolution toward a common oncogenic driver mutation. This is the first case of multiple synchronous lung tumors each harboring a distinct MET exon 14 splice site mutation.

Dynamic computed tomography (CT) of the airways is increasingly used to evaluate patients with suspected expiratory central airway collapse, but current protocols are susceptible to inadequate exhalation caused by variable patient compliance with breathing instructions during the expiratory phase. We developed and tested a low-cost single-use expiratory airflow indicator device that was designed to improve study quality by providing a visual indicator to both patient and operator when adequate expiratory flow was attained.A total of 56 patients undergoing dynamic airway CT were evaluated, 35 of whom were scanned before introduction of the indicator device (control group), with the rest comprising the intervention group. Lung volumes and tracheal cross-sectional areas on inspiratory/expiratory phases were computed using automated lung segmentation and quantitative software analysis. Inadequate exhalation was defined as absolute volume change of500 mL during the expiratory phase.Fewer patients in the intervention group demonstrated inadequate exhalation. The average change in volume was higher in the intervention group (P=0.004), whereas the average minimum tracheal cross-sectional area was lower (P=0.01).The described expiratory airflow indicator device can be used to ensure adequate exhalation during the expiratory phase of dynamic airway CT. A higher frequency of adequate exhalation may improve reliability and sensitivity of dynamic airway CT for diagnosis of expiratory central airway collapse.

Evaluations of patients with pulmonary hypertension (PH) commonly include chest CT imaging. We hypothesized that cardiac chamber volumes calculated from the same CT scans can yield additional information to distinguish PH related to left-sided heart disease (World Health Organization group 2) from other PH subtypes.Patients who had PH confirmed by right heart catheterization and contrast-enhanced chest CT studies were enrolled in this retrospective multicenter study. Cardiac chamber volumes were calculated using automated segmentation software and compared between group 2 and non-group 2 patients with PH.This study included 114 patients with PH, 27 (24%) of whom were classified as group 2 based on their pulmonary capillary wedge pressure. Patients with group 2 PH exhibited significantly larger median left atrial (LA) volumes (118 mL vs 63 mL; P .001), larger median left ventricular (LV) volumes (90 mL vs 76 mL; P = .02), and smaller median right ventricular (RV) volumes (173 mL vs 210 mL; P = .005) than did non-group 2 patients. On multivariate analysis adjusted for age, sex, and mean pulmonary arterial pressure, group 2 PH was significantly associated with larger median LA and LV volumes (P .001 and P = .008, respectively) and decreased volume ratios of RA/LA, RV/LV, and RV/LA (P = .001, P = .004, and P .001, respectively). Enlarged LA volumes demonstrated a high discriminatory ability for group 2 PH (area under the curve, 0.92; 95% CI, 0.870-0.968).Volumetric analysis of the cardiac chambers from nongated chest CT scans, particularly with findings of an enlarged left atrium, exhibited high discriminatory ability for identifying patients with PH due to left-sided heart disease.

8537 Background: Five-year survival for stage I-II lung cancer is quite low even after complete surgical resection. Current guidelines recommend adjuvant treatment only for selected patients with stage II or higher disease. A prediction model that identifies patients at high risk of recurrence who may benefit from adjuvant treatment is greatly needed. Many existing prediction models include a small number of genes that were found to be significant in previous studies. We propose using artificial intelligence to analyze a microarray of > 20,000 well-annotated genes to create a model that predicts recurrence after surgical resection of stage I-II lung cancer. Methods: We identified 275 patients who underwent surgical resection for pathologic stage I-II lung adenocarcinoma or squamous cell carcinoma from 2009 to 2019 in our institution’s prospective surgical database. We excluded patients who had follow up time less than 3 years or received adjuvant therapy and had not had a recurrence, as well as patients with missing specimen blocks. Patient characteristics and recurrence information were obtained from chart review. The patients were divided into training (192 patients) and validation (83 patients) cohorts, and the recurrence status for the validation cohort was initially blinded. Gene expression levels were generated using Clariom S human array (ThermoFisher) from 10um sections cut from the formalin-fixed, paraffin-embedded surgical specimen blocks. The artificial intelligence algorithm Support Vector Machine (SVM) was used to create a prediction model for recurrence using the gene expression and recurrence status of the patients in the training cohort. The model was then tested on the validation cohort using Kaplan-Meier analysis and the area under the receiver operator curve (AUROC). Results: The recurrence prediction model separated the validation cohort into 15 (18.1%) patients in the high-risk group and 68 (81.9%) patients in the low-risk group. Kaplan-Meier analysis showed the five-year disease-free survival was significantly higher in the low-risk group compared to the high-risk group (86 vs. 50%, HR = 4.41, p = 0.0025). The AUROC for predicting recurrence was 0.744. Conclusions: Our model uses artificial intelligence to successfully predict recurrence after surgical resection for stage I-II non-small cell lung cancer. With an AUROC of 0.744, our model outperforms previously described models with AUROC up to 0.6. Our model separates patients into high-risk and low-risk groups, which will make management decisions clearer compared to other models that also include an intermediate-risk group. Patients in the low-risk group had 86% five-year disease-free survival; patients in the high-risk group had 50% five-year disease-free survival and may benefit from increased postoperative surveillance or adjuvant therapy.

Extraskeletal findings detected on whole-body low-dose unenhanced computed tomography (CT) as a part of F-NaF PET/CT scans can be numerous and present challenges for further management. Here, we investigate the frequency and clinical significance of extraskeletal findings among 130 consecutive patients undergoing F-NaF PET/CT for osseous metastatic disease.F-NaF PET/CT performed on 130 patients (101 men and 29 women; mean age: 61.4 years) with biopsy-proven malignancies were reviewed independently. Incidental soft tissue findings detected on unenhanced low-dose CT portions of the scans were compiled and categorized by clinical significance.A total of 275 incidental extraskeletal CT findings were observed in 114 out of 130 patients (87.7%). Seven patients (5.4%) showed clinically significant findings. One patient developed new lung nodules that were resected and proven to be metastases. Two patients showed new hypodense hepatic lesions that were highly suspicious for liver metastases. One patient with prostate cancer was found to have previously unknown retroperitoneal lymphadenopathy. Three patients showed indeterminate renal and adrenal lesions that necessitated further correlative imaging.Although CT indicated a large number of incidental extraskeletal lesions in the majority of patients undergoing F-NaF PET/CT, clinically significant incidental findings requiring further evaluation were relatively infrequently observed in 5.4% of patients. Thus, the low-dose unenhanced CT in F-NaF PET/CT performed for oncologic evaluation may indicate unexpected soft tissue lesions that can impact patient management and therefore should be interpreted by physicians skilled in CT reading, with correlation to available imaging, and familiar with established guidelines for work-up of incidental findings.

To determine if pre-treatment non-target lung FDG-PET uptake predicts for symptomatic radiation pneumonitis (RP) following lung stereotactic ablative radiotherapy (SABR).We reviewed a 258 patient database from our institution to identify 28 patients who experienced symptomatic (grade ⩾ 2) RP after SABR, and compared them to 57 controls who did not develop symptomatic RP. We compared clinical, dosimetric and functional imaging characteristics between the 2 cohorts including pre-treatment non-target lung FDG-PET uptake.Median follow-up time was 26.9 months. Patients who experienced symptomatic RP had significantly higher non-target lung FDG-PET uptake as measured by mean SUV (p 0.0001) than controls. ROC analysis for symptomatic RP revealed area under the curve (AUC) of 0.74, with sensitivity 82.1% and specificity 57.9% with cutoff mean non-target lung SUV 0.56. Predictive value increased (AUC of 0.82) when mean non-target lung SUV was combined with mean lung dose (MLD). We developed a 0-2 point model using these 2 variables, 1 point each for SUV 0.56 or MLD 5.88 Gy equivalent dose in 2 Gy per fraction (EQD2), predictive for symptomatic RP in our cohort with hazard ratio 10.01 for score 2 versus 0 (p 0.001).Patients with elevated pre-SABR non-target lung FDG-PET uptake are at increased risk of symptomatic RP after lung SABR. Our predictive model suggests patients with mean non-target lung SUV 0.56 and MLD 5.88 Gy EQD2 are at highest risk. Our predictive model should be validated in an external cohort before clinical implementation.

Case Presentation A 38-year-old woman presented with 2 months of dry cough, progressive shortness of breath, central chest pain, nausea, vomiting, and dizziness. She was previously healthy and was not taking any medications. She denied fever, night sweats, or weight loss. She had a two pack-year smoking history and had quit smoking at 27 years of age. She denied drug use and had no recent travel history. Family history was pertinent for ovarian cancer, breast cancer, and colon cancer.

Lung transplant is performed to treat a number of end-stage pulmonary diseases. Because many of the imaging features of post-transplant complications are nonspecific, accurate interpretation of surveillance scans following lung transplantation requires knowledge of modern surgical techniques and predictable post-procedure complications based on the time course after surgery. Computed tomography (CT) is the mainstay of lung transplantation imaging and will be the primary focus of this review.

Background Emerging data support aggressive local treatment of oligometastatic non–small-cell lung cancer (NSCLC) patients. We sought to determine whether the metabolic burden of disease found by fluorodeoxyglucose positron emission tomography at the time of high-dose radiotherapy (RT) for oligometastatic NSCLC can serve as a prognostic biomarker. Materials and Methods We conducted a retrospective cohort study of 67 RT treatment courses in 55 patients with oligometastatic NSCLC who had undergone high-dose RT to all sites of active disease at our institution. The metabolic tumor volume, total lesion glycolysis (TLG), and maximum standardized uptake value of all lesions were measured on the pretreatment fluorodeoxyglucose positron emission tomography scans. Cox regression analysis was used to assess the influence of imaging and clinical factors on overall survival (OS). Results On univariate analysis, a greater metabolic tumor volume and TLG were predictive of shorter OS (hazard ratio of death, 2.42 and 2.14, respectively; P = .009 and P = .004, respectively). The effects remained significant on multivariate analysis. Neither the maximum standardized uptake value nor the number of lesions was significantly associated with OS. Patients within the highest quartile of TLG values (> 86.8 units) had a shorter median OS than those within the lower 3 quartiles (12.4 vs. 30.1 months; log-rank P = .014). Conclusion The metabolic tumor burden was prognostic of OS and might help to better select oligometastatic NSCLC patients for locally ablative therapy.

Left heart disease is associated with left atrial enlargement and is a common cause of pulmonary hypertension (PH). We investigated the relationship between left atrium maximal axial cross-sectional area (LA-MACSA), as measured on chest computed tomography (CT), and PH due to left heart disease (World Health Organization group 2) in patients with right heart catheterization-proven PH.A total of 165 patients with PH who had undergone right heart catheterization with pulmonary artery pressure and pulmonary capillary wedge pressure (PCWP) measurements and nongated chest CTs were included. LA-MACSA, LA anterior-posterior, and LA transverse measurements were independently obtained using the hand-drawn region-of-interest and distance measurement tools on standard PACS by 2 blinded cardiothoracic radiologists. Nonparametric statistical analyses and receiver operating characteristic curve were performed.Forty-three patients had group 2 PH (PCWP15 mm Hg), and 122 had nongroup 2 PH (PCWP≤15 mm Hg). Median LA-MACSA was significantly different between the group 2 PH and nongroup 2 PH patients (2312 vs. 1762 mm, P0.001). Interobserver concordance correlation for LA-MACSA was high at 0.91 (P0.001). At a threshold of 2400 mm, LA-MACSA demonstrated 93% specificity for classifying group 2 PH (area under the curve, 0.73; P0.001).LA-MACSA is a readily obtainable and reproducible measurement of left atrial enlargement on CT and can distinguish between group 2 and nongroup 2 PH with high specificity.

Purpose To determine if regional ventilation within irradiated lung volume predicts change in pulmonary function test (PFT) measurements after stereotactic ablative radiotherapy (SABR) of lung tumors. Methods We retrospectively identified 27 patients treated from 2007 to 2014 at our institution who received: (1) SABR without prior thoracic radiation; (2) pre-treatment 4-dimensional computed tomography (4-D CT) imaging; (3) pre- and post-SABR PFTs 20BED3 ) as the quotient of mean ventilation (mean Jacobian-based per-voxel volume change on deformably registered inhale/exhale 4-D CT phases) within the 20Gy biologically effective dose ( α / β =3Gy) isodose volume and that of the total lung volume (TLV). Results Most patients had moderate to very severe COPD by GOLD criteria ( n =19, 70.1%). Higher VR 20BED3 significantly predicted worse change in Forced Expiratory Volume/s normalized by baseline value (ΔFEV 1 /FEV 1pre , p =0.04); n =7 had VR 20BED3 >1 (high regional ventilation) and worse ΔFEV 1 /FEV 1pre (median=−0.16, range=−0.230 to −0.20). Five had VR 20BED3 1 /FEV 1pre (median=0.13, range=0.07 to 0.20). In a multivariable linear model, increasing VR 20BED3 and time to post-SABR PFT predicted decreasing ΔFEV 1 /FEV 1pre ( R 2 =0.25, p =0.03). Conclusions After SABR to high versus low functioning lung regions, we found worsened or improved global pulmonary function, respectively. If pre-SABR VR 20BED3 is validated as a predictor of eventual post-SABR PFT in larger studies, it may be used for individualized treatment planning to preserve or even improve pulmonary function after SABR.

Coccidioidomycosis, commonly called "valley fever," "San Joaquin fever," "desert fever," or "desert rheumatism," is a multi-system illness caused by infection with Coccidioides fungi (C. immitis or C. posadasii). This organism is endemic to the desert Southwest regions of the United States and Mexico and to parts of South America. The manifestations of infection occur along a spectrum from asymptomatic to mild self-limited fever to severe disseminated disease.Review of the English-language literature.There are five broad indications for surgical intervention in patients with coccidioidomycosis: Tissue diagnosis in patients at risk for co-existing pathology, perforation, bleeding, impingement on critical organs, and failure to resolve with medical management. As part of a multidisciplinary team, surgeons may be responsible for the care of infected patients, particularly those with severe disease.This review discusses the history, microbiology, epidemiology, pathology, diagnosis, and treatment of coccidioidomycosis, focusing on situations that may be encountered by surgeons.

Cardiac FDG-PET is emerging as a frequently used imaging modality in the diagnosis of cardiac sarcoidosis; however, there is a scarcity of published data and no uniform consensus on using serial FDG-PET in guiding immunosuppressive therapy in this patient cohort. We studied consecutive patients

The authors present an excellently documented case that demonstrates the radiologic-pathologic correlation of 2009 influenza A (H1N1) and its complications and discuss possible reasons for severe complications in patients with compromised immune status.

Human alkyladenine-DNA glycosylase (AAG) initiates base excision repair (BER) of alkylated and deaminated bases in DNA. Here, we assessed the mutability of the AAG substrate binding pocket, and the essentiality of individual binding pocket amino acids for survival of methylation damage. We used oligonucleotide-directed mutagenesis to randomize 19 amino acids, 8 of which interact with substrate bases, and created more than 4.5 million variants. We expressed the mutant AAGs in repair-deficient Escherichia coli and selected for protection against the cytotoxicity of either methylmethane sulfonate (MMS) or methyl-lexitropsin (Me-lex), an agent that produces 3-methyladenine as the predominant base lesion. Sequence analysis of 116 methylation-resistant mutants revealed no substitutions for highly conserved Tyr(127)and His(136). In contrast, one mutation, L180F, was greatly enriched in both the MMS- and Me-lex-resistant libraries. Expression of the L180F single mutant conferred 4.4-fold enhanced survival at the high dose of MMS used for selection. The homogeneous L180F mutant enzyme exhibited 2.2-fold reduced excision of 3-methyladenine and 7.3-fold reduced excision of 7-methylguanine from methylated calf thymus DNA. Decreased excision of methylated bases by the mutant glycosylase could promote survival at high MMS concentrations, where the capacity of downstream enzymes to process toxic BER intermediates may be saturated. The mutant also displayed 6.6- and 3.0-fold reduced excision of 1,N(6)-ethenoadenine and hypoxanthine from oligonucleotide substrates, respectively, and a 1.7-fold increase in binding to abasic site-containing DNA. Our work provides in vivo evidence for the substrate binding mechanism deduced from crystal structures, illuminates the function of Leu(180) in wild-type human AAG, and is consistent with a role for balanced expression of BER enzymes in damage survival.

Mutagenesis of protein-encoding sequences occurs ubiquitously; it enables evolution, accumulates during aging, and is associated with disease. Many biotechnological methods exploit random mutations to evolve novel proteins. To quantitate protein tolerance to random change, it is vital to understand the probability that a random amino acid replacement will lead to a protein's functional inactivation. We define this probability as the “ x factor.” Here, we develop a broadly applicable approach to calculate x factors and demonstrate this method using the human DNA repair enzyme 3-methyladenine DNA glycosylase (AAG). Three gene-wide mutagenesis libraries were created, each with 10 5 diversity and averaging 2.2, 4.6, and 6.2 random amino acid changes per mutant. After determining the percentage of functional mutants in each library using high-stringency selection (>19,000-fold), the x factor was found to be 34% ± 6%. Remarkably, reanalysis of data from studies of diverse proteins reveals similar inactivation probabilities. To delineate the nature of tolerated amino acid substitutions, we sequenced 244 surviving AAG mutants. The 920 tolerated substitutions were characterized by substitutability index and mapped onto the AAG primary, secondary, and known tertiary structures. Evolutionarily conserved residues show low substitutability indices. In AAG, β strands are on average less substitutable than α helices; and surface loops that are not involved in DNA binding are the most substitutable. Our results are relevant to such diverse topics as applied molecular evolution, the rate of introduction of deleterious alleles into genomes in evolutionary history, and organisms' tolerance of mutational burden.

Mutations in DNA accrue relentlessly, largely via stochastic processes. Random changes accumulate, eventually disabling genetic components which result in the formation of the cancer phenotype. Given the infrequency of measured nucleotide changes and the requirement for several mutations to occur in the same cell, it has been postulated that the rate of mutation must become elevated early in the course of evolution of the cancer. Recently, large scale sequencing of tumor DNA has sought to directly measure random mutations. We discuss the implications of these findings and the factors that must be considered in order for fruitful determination of whether a mutator phenotype is a necessary precursor for cancer.

The multiplicity of mutations found in human cancers reflects the consequences of breakdown in genome maintenance and helps to provide insight into the origins of malignancy. Keywords: genetic instability; DNA damage; DNA repair; mutation; cancer

Molecular biology critically depends upon the isolation of desired DNA sequences. Flow cytometry, with its capacity to interrogate and sort more than 50,000 cells/s, shows great potential to expedite clone characterization and isolation. Intrinsic heterogeneity of protein expression levels in cells limits the utility of single fluorescent reporters for cell-sorting. Here, we report a novel dual-fluorescence strategy that overcomes the inherent limitations of single reporter systems by controlling for expression variability. We demonstrate a dual-reporter system using the green fluorescent protein (GFP) gene fused to the Discosoma red fluorescent protein (DsRed) gene. The system reports the successful insertion of foreign DNA with the loss of DsRed fluorescence and the maintenance of GFP fluorescence. Single cells containing inserts are readily recognized by their altered ratios of green to red fluorescence and separated using a high-speed cell-sorter for further processing. This novel reporter system and vector were successfully validated by shotgun library construction, cloned sequence isolation, PCR amplification and DNA sequencing of cloned inserts from bacteria after cell-sorting. This simple, robust system can also be adapted for diverse biosensor assays and is amenable to miniaturization. We demonstrated that dual-fluorescence reporting coupled with high-speed cell-sorting provides a more efficient alternative to traditional methods of clone isolation.