Predictors of Episode-of-Care Costs for Ankle Fractures

Ankle fractures are one of the most resource-consuming traumatic orthopedic injuries. Few studies have successfully evaluated the episode-of-care costs (EOCC) of common traumatic orthopedic injuries. The objective of this study was to determine the EOCC associated with the surgical management of ankle fractures. A retrospective cohort study of 105 consecutive patients who underwent open reduction internal fixation of an isolated ankle fracture at a Canadian Level-1 trauma center was conducted. Episode-of-care costs were generated using an activity-based costing framework. The median global episode-of-care cost for ankle fracture surgeries performed at the studied institution was $3,487 CAD [IQR 880] ($2,685 USD [IQR 616]). Patients aged 60 to 90 years had a significantly higher median EOCC than younger patients (p=0.01). Supination-adduction injuries had a significantly higher median EOCC than other injury patterns (p=0.01). The median EOCC for patients who underwent surgery within 10 days of their injury ($3,347 CAD [582], $2,577 USD [448]) was significantly lower than the cost for patients who had their surgery delayed 10 days or more after the injury ($3,634 CAD [776], $2,798 USD [598]) (p=0.03). Patient sex, anesthesia type, ASA score and surgeon's fellowship training did not affect the EOCC. This study provides valuable data on predictors of EOCC in the surgical management of ankle fractures. Delaying simple ankle fracture cases due to operating time constraints can increase the total cost and burden of these fractures on the healthcare system. In addition, this study provides a framework for future episode-of-care cost analysis studies in orthopedic surgery. LEVEL OF EVIDENCE: Level III.

Transbronchial Lung Cryobiopsy and Surgical Lung Biopsy: A Prospective Multi-Centre Agreement Clinical Trial (CAN-ICE)

Rationale: Transbronchial cryobiopsy (TBCB) for the diagnosis of interstitial lung disease (ILD) has shown promising results, but prospective studies with matched surgical lung biopsy (SLB) have yielded conflicting results. Objectives: We aimed to assess within- and between-center diagnostic agreement between TBCB and SLB at both the histopathologic and multidisciplinary discussion (MDD) levels in patients with diffuse ILD. Methods: In a multicenter prospective study, we performed matched TBCB and SLB in patients referred for SLB. After a blinded review by three pulmonary pathologists, all cases were reviewed by three independent ILD teams in an MDD. MDD was performed first with TBCB, then with SLB in a second session. Within-center and between-center diagnostic agreement was evaluated using percentages and correlation coefficients. Measurements and Main Results: Twenty patients were recruited and underwent contemporaneous TBCB and SLB. Within-center diagnostic agreement between TBCB-MDD and SLB-MDD was reached in 37 of the 60 (61.7%) paired observations, resulting in a Cohen's κ value of 0.46 (95% confidence interval [CI], 0.29-0.63). Diagnostic agreement increased among high-confidence or definitive diagnoses on TBCB-MDD (21 of 29 [72.4%]), but not significantly, and was more likely among cases with SLB-MDD diagnoses of idiopathic pulmonary fibrosis than fibrotic hypersensitivity pneumonitis (13 of 16 [81.2%] vs. 16 of 31 [51.6%]; P = 0.047). Between-center agreement for cases was markedly higher for SLB-MDD (κ = 0.71 [95% CI, 0.52-0.89]) than TBCB-MDD (κ = 0.29 [95% CI, 0.09-0.49]). Conclusions: This study demonstrated moderate TBCB-MDD and SLB-MDD diagnostic agreement for ILD, while between-center agreement was fair for TBCB-MDD and substantial for SLB-MDD. Clinical trial registered with www.clinicaltrials.gov (NCT02235779).

Towards recycling of waste carbon fiber: Strength, morphology and structural features of recovered carbon fibers

Carbon fiber is one of the most widely used materials in high demand applications due to its high specific properties, however, its post-recycling properties limit its use to low performance applications. In this research, the carbon fiber recovering is examined using two methods: two-step pyrolysis and microwave-assisted thermolysis. The results indicate that the fibers recovered by pyrolysis show reduced surface and structural damage, maintaining the original mechanical properties of the fiber with losses below 5%. The fibers recovered by microwaves undergo significant surface changes that reduce their tensile strength by up to 60% and changes in their graphitic structure, increasing their degree of crystallinity by Raman index I_D/I_G from 1.98 to 2.86 and their amorphous degree by I_D"/I_G ratio from 0.411 to 1.599. Recovering fibers from microwave technique is 70% faster compared to two step pyrolysis, and provides recycled fibers with superior surface activation with the presence of polar functional groups -OH, -CO, and -CH that react with the epoxy matrix. The thermal, morphological, structural and mechanical characterizations of the recovered fibers detailed in this work provide valuable findings to evaluate their direct reuse in new composite materials.

Wait Times and Survival in Lung Cancer Patients across the Province of Quebec, Canada

Lung cancer is the leading cause of cancer death worldwide, with a five-year survival of 22% in Canada. Guidelines recommend rapid evaluation of patients with suspected lung cancer, but the impact on survival remains unclear. We reviewed medical records of all patients with newly diagnosed lung cancer in four hospital networks across the province of Quebec, Canada, between 1 February and 30 April 2017. Patients were followed for 3 years. Wait times for diagnosis and treatment were collected, and survival analysis using a Cox regression model was conducted. We included 1309 patients, of whom 39% had stage IV non-small cell lung cancer (NSCLC). Median wait times were, in general, significantly shorter in patients with stage III–IV NSCLC or SCLC. Surgery was associated with delays compared to other types of treatments. Median survival was 12.9 (11.1–15.7) months. The multivariate survival model included age, female sex, performance status, histology and stage, treatment, and the time interval between diagnosis and treatment. Longer wait times had a slightly protective to neutral effect on survival, but this was not significant in the stage I–II NSCLC subgroup. Wait times for the diagnosis and treatment of lung cancer were generally within targets. The shorter wait times observed for advanced NSCLC and SCLC might indicate a tendency for clinicians to act quicker on sicker patients. This study did not demonstrate the detrimental effect of longer wait times on survival.

Outcomes Following Surgical Lung Biopsy for Interstitial Lung Diseases: A Monocenter Experience

BACKGROUND

 Surgical lung biopsy (SLB) is considered in the investigation of interstitial lung diseases (ILDs) when a complete clinical evaluation and a multidisciplinary discussion (MDD) do not allow the clinician to make a confident diagnosis. Owing to the risk of the procedure, an appropriate assessment of the risk/benefit ratio prior to the intervention is recommended. We aimed to assess the postoperative outcomes and diagnostic yield of SLB for the investigation of ILD in a tertiary care institution.

METHODS

 We conducted a retrospective cohort study of consecutive subjects who underwent a SLB for the investigation of ILD in our center from 2009 to 2020. The postoperative mortality and complications rates as well as the diagnostic yield of the procedure were assessed.

RESULTS

 Of the 1,805 patients newly investigated for ILD in our center from 2009 to 2020, 71 (3.93%) underwent a SLB. At days 30 and 90, the mortality rates were 0 and 2.8%, whereas 4.3 and 7.6% patients experienced an acute ILD exacerbation, respectively. In addition, 4 (5.8%) patients experienced infectious complications and 5 (7.0%) presented prolonged air leaks (all within 30 days). A definite pathological diagnosis was made in 47 (66.2%) patients. Following postoperative MDD, a confident diagnosis was made in 61 patients (85.9%) and resulted in a change of therapy in 49 (69.0%) patients.

CONCLUSION

 SLB for the diagnosis of unclassifiable ILDs is associated with low mortality but significant morbidity. However, it results in a confident diagnosis and a change in therapy in the majority of patients.

Effect of the donor´s age and type of extender (egg yolk versus clarified egg yolk) over the sperm quality of Majorera bucks preserved at 4 ºC: in vitro results and fertility trials

This study assessed the effect of donor´s age and two different extenders in the sperm quality of chilled semen in Majorera bucks. In experiment 1, semen was individually processed from 5 young (10–12 months old) and 4 mature (3–5 years old) bucks and then was diluted in two different extenders: EY (Tris‐glucose, 12% egg yolk) and CEY (Tris‐glucose, 12% clarified egg yolk) and cooled at 4°C; semen quality (sperm motility, percentages of alive spermatozoa, acrosome status and abnormal spermatozoa) was evaluated at 24, 48, 72 and 96 hr after cooling. In experiment II, 72 Majorera goats were assigned to four experimental groups: for groups 24‐EY (n = 18) and 24‐CEY (n = 18), goats were inseminated with EY and CEY cooled semen for 24 hr, respectively, while for groups 72‐EY (n = 18) and 72‐CEY (n = 18), goats were inseminated with EY and CEY cooled semen for 72 hr, respectively. In vitro results confirmed that only ejaculate volume and sperm concentration were significantly different between young and mature bucks. In addition, semen quality was similar between both diluents, presenting values for the first 48 hr similar to that recorded in fresh samples. The fertility rate was around 70% after 24 hr (4°C) in both groups, but the kidding rate was significantly lower (44.4%, p < .05) in goats inseminated with EY diluent preserved for 72 hr. Our results showed that the semen samples may be stored at 4°C in media with egg yolk or clarified egg yolk, and, therefore, the use of clarified egg yolk may represent a valid alternative to chill semen samples. Finally, young bucks (older than 10–12 months) of Majorera breed could be successfully used in breeding programmes with similar efficacy to older males.

Malignant pleural mesothelioma: Comparison of surgery-based trimodality therapy to medical therapy at two tertiary academic institutions

OBJECTIVES

Medical management based on palliative chemotherapy is currently the standard of care in malignant pleural mesothelioma (MPM). Median survival of 12-16 months has been reported with modern chemotherapy regimens with or without anti-angiogenic agents. Multimodality therapy incorporating cytoreductive surgery, systemic chemotherapy and radiotherapy has been offered for years to fit patients with early-stage disease, but its role remains debated. Our objective was to compare overall survival in patients offered multimodality therapy in a specialized clinic setting in London, UK to that of patients offered exclusively medical treatment at another academic institution in Quebec, Canada.

MATERIALS AND METHODS

We retrospectively compared the survival rates of 2 separate cohorts of patients treated consecutively: Cohort 1 (n = 106) received multimodality therapy including systemic chemotherapy, extended pleurectomy/decortication (P/D) and prophylactic radiotherapy in London (United Kingdom) between 2009 and 2016, while Cohort 2 (n = 98) received medical treatment at the Quebec Heart and Lung Institute (Canada) during the same period.

RESULTS

In Cohort 1, all patients but two completed trimodality therapy. In cohort 2, 51 % received palliative care only and 40 % received systemic chemotherapy. Median survival was 32 months vs 10 months in Cohort 1 and Cohort 2, respectively (hazard ratio with age, gender, pathology and TNM staging as covariates: 3.81; 95 % CI: 2.67-5.45; p < 0.0001). Similar results were obtained in sensitivity analyses, after excluding those who received best supportive care only and in a propensity score-matched analysis.

CONCLUSION

Aggressive therapy of MPM using cancer-directed surgery, systemic chemotherapy and prophylactic radiotherapy may provide a significant survival benefit in selected patients.

Risk Perception Among a Lung Cancer Screening Population

BACKGROUND

A successful lung cancer screening program requires a patient cohort at sufficient risk of developing cancer who are willing to participate. Among other factors, a patient's lung cancer risk perception may inform their attitudes toward screening and smoking cessation programs.

RESEARCH QUESTION

This study analyzed data from the Pan-Canadian Early Detection of Lung Cancer (PanCan) Study to address the following questions: Which factors are associated with the perception of lung cancer risk? Is there an association between risk perception for lung cancer and actual calculated risk? Is there an association between risk perception for lung cancer and the intent to quit smoking? Are there potential targets for lung cancer screening awareness?

STUDY DESIGN AND METHODS

The PanCan study recruited current or former smokers aged 50 to 75 years who had at least a 2% risk of developing lung cancer over 6 years to undergo low-dose screening CT. Risk perception and worry about lung cancer were captured on a baseline questionnaire. Cumulative logistic regression analysis was used to assess the relationship between baseline risk variables and both lung cancer risk perception and worry.

RESULTS

Among the 2,514 individuals analyzed, a higher perceived risk of lung cancer was positively associated with calculated risk (P = .032). Younger age, being a former smoker, respiratory symptoms, lower FEV₁, COPD, and a family history of lung cancer were associated with higher perceived risk. Conversely, a consistent relationship between calculated risk and worry was not identified. There was a positive association between risk perception and lung cancer worry and reported intent to quit smoking.

INTERPRETATION

Individuals' lung cancer risk perception correlated positively with calculated risk in a screening population. Promotion of screening programs may benefit from focusing on factors associated with higher risk perception; conversely, harnessing worry seemingly holds less value.

Chronic obstructive pulmonary disease prevalence and prediction in a high-risk lung cancer screening population

Background

Chronic obstructive pulmonary disease (COPD) is an underdiagnosed condition sharing risk factors with lung cancer. Lung cancer screening may provide an opportunity to improve COPD diagnosis. Using Pan-Canadian Early Detection of Lung Cancer (PanCan) study data, the present study sought to determine the following: 1) What is the prevalence of COPD in a lung cancer screening population? 2) Can a model based on clinical and screening low-dose CT scan data predict the likelihood of COPD?

Methods

The single arm PanCan study recruited current or former smokers age 50–75 who had a calculated risk of lung cancer of at least 2% over 6 years. A baseline health questionnaire, spirometry, and low-dose CT scan were performed. CT scans were assessed by a radiologist for extent and distribution of emphysema. With spirometry as the gold standard, logistic regression was used to assess factors associated with COPD.

Results

Among 2514 recruited subjects, 1136 (45.2%) met spirometry criteria for COPD, including 833 of 1987 (41.9%) of those with no prior diagnosis, 53.8% of whom had moderate or worse disease. In a multivariate model, age, current smoking status, number of pack-years, presence of dyspnea, wheeze, participation in a high-risk occupation, and emphysema extent on LDCT were all statistically associated with COPD, while the overall model had poor discrimination (c-statistic = 0.627 (95% CI of 0.607 to 0.650). The lowest and the highest risk decile in the model predicted COPD risk of 27.4 and 65.3%.

Conclusions

COPD had a high prevalence in a lung cancer screening population. While a risk model had poor discrimination, all deciles of risk had a high prevalence of COPD, and spirometry could be considered as an additional test in lung cancer screening programs.

Trial registration

(Clinical Trial Registration: ClinicalTrials.gov, number NCT00751660, registered September 12, 2008)

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-020-01344-y.

Division of an Iliac Crest Bone Biopsy Specimen to Allow Histomorphometry, Immunohistochemical, Molecular Analysis, and Tissue Banking: Technical Aspect and Applications

The evaluation of bone complications in chronic kidney disease (CKD) often requires a bone biopsy, the analysis of which can refine the diagnosis of bone defects. Bone histomorphometry performed on sections of the iliac crest biopsy remains the reference procedure for the quantitative assessment of bone health in CKD patients, whereas immunohistochemistry and other molecular biology analyses are indispensable tools for studying the disrupted signaling pathways. Traditionally, the whole iliac crest biopsy was included in methyl‐methacrylate (MMA) and was exclusively used for bone histomorphometry to describe static, dynamic, and structural parameters. Therefore, further molecular analysis of the bone tissue or the need for tissue banking would require a second biopsy to be made, because inclusion in MMA prevents the extraction of good‐quality nucleic acids. In this work, we describe a simple approach to divide a single iliac crest bone biopsy into multiple parts. This allows for simultaneous assessments of histology, immunohistochemistry, biomolecular analysis, and tissue banking while preserving the same bone surface area for histomorphometry. © 2020 American Society for Bone and Mineral Research © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Consensus statement: summary of the Quebec Lung Cancer Network recommendations for prioritizing patients with thoracic cancers in the context of the COVID-19 pandemic

Background

The emergence of covid-19 has the potential to change the way in which the health care system can accommodate various patient populations and might affect patients with non-covid-19 problems. The Quebec Lung Cancer Network, which oversees thoracic oncology services in the province of Quebec under the direction of the Ministère de la Santé et des Services sociaux, convened to develop recommendations to deal with the potential disruption of services in thoracic oncology in the province of Quebec. The summary provided here has been adapted from the original document posted on the Programme québécois du cancer Web site at: https://www.msss.gouv.qc.ca/professionnels/documents/coronavirus-2019-ncov/PJ1_Recommandations_oncologie-thoracique-200415.pdf.

Methods

Plans to optimize the health care system and potentially to prioritize services were discussed with respect to various levels of activity. For each level-of-activity scenario, suggestions were made for the services and treatments to prioritize and for those that might have to be postponed, as well as for potential alternatives to care.

Results

The principal recommendation is that the cancer centre executive committee and the multidisciplinary tumour board always try to find a solution to maintain standard-of-care therapy for all patients with thoracic tumours, using novel approaches to treatment and the adoption of a network approach to care, as needed.

Conclusions

The effect of the covid-19 pandemic on the health care system remains unpredictable and requires that cancer teams unite and offer the most efficient and innovative therapies to all patients under the various conditions that might be forced upon them.

Improving Lung Function in Severe Heterogenous Emphysema with the Spiration Valve System (EMPROVE). A Multicenter, Open-Label Randomized Controlled Clinical Trial

Rationale: Less invasive, nonsurgical approaches are needed to treat severe emphysema.

Objectives: To evaluate the effectiveness and safety of the Spiration Valve System (SVS) versus optimal medical management.

Methods: In this multicenter, open-label, randomized, controlled trial, subjects aged 40 years or older with severe, heterogeneous emphysema were randomized 2:1 to SVS with medical management (treatment) or medical management alone (control).

Measurements and Main Results: The primary efficacy outcome was the difference in mean FEV₁ from baseline to 6 months. Secondary effectiveness outcomes included: difference in FEV₁ responder rates, target lobe volume reduction, hyperinflation, health status, dyspnea, and exercise capacity. The primary safety outcome was the incidence of composite thoracic serious adverse events. All analyses were conducted by determining the 95% Bayesian credible intervals (BCIs) for the difference between treatment and control arms. Between October 2013 and May 2017, 172 participants (53.5% male; mean age, 67.4 yr) were randomized to treatment (n = 113) or control (n = 59). Mean FEV₁ showed statistically significant improvements between the treatment and control groups—between-group difference at 6 and 12 months, respectively, of 0.101 L (95% BCI, 0.060–0.141) and 0.099 L (95% BCI, 0.048–0.151). At 6 months, the treatment group had statistically significant improvements in all secondary endpoints except 6-minute-walk distance. Composite thoracic serious adverse event incidence through 6 months was greater in the treatment group (31.0% vs. 11.9%), primarily due to a 12.4% incidence of serious pneumothorax.

Conclusions: In patients with severe heterogeneous emphysema, the SVS shows significant improvement in multiple efficacy outcomes, with an acceptable safety profile.

Clinical trial registered with www.clinicaltrials.gov (NCT01812447).

Trial marketing in the Pan-Canadian Early Detection of Lung Cancer Study

BACKGROUND

Recruitment to clinical trials is suboptimal, increasing costs, and delaying the potential implementation of clinical advances. Among other barriers, the lack of marketing experience among trialists may limit recruitment. In this observational study, in the context of the Pan-Canadian Early Detection of Lung Cancer Trial, we assessed the value of a motivational survey of study participants in planning a tailored advertising campaign and analysed the value of individual components of advertising in generating telephone calls to the study and recruited subjects.

METHODS

The Pan-Canadian Early Detection of Lung Cancer Trial was a single arm study assessing risk modelling for lung cancer screening by low-dose computed tomography scan and autofluorescence bronchoscopy. Individuals were recruited to eight sites across Canada without a central marketing plan. On contact with the study, individuals reported how they heard about the study according to a predefined list. One site, the Juravinski Cancer Centre, worked with a marketing expert to develop a survey to assess participant motivations, source of study awareness, and personal habits. The survey was used to develop a media campaign for recruitment. Media events were collected from all sites. The primary analysis assessed the number of telephone contacts and recruited subjects associated with various media factors. Individual print media characteristics were assessed for their effect on recruitment.

RESULTS

At all sites, 7059 individuals contacted the study, and 2537 were eligible and recruited. Among 52 individuals completing the Juravinski Cancer Centre survey, motivation included concern for personal risk of lung cancer (71%), followed by desire to contribute to a cure (67%), followed by personal knowledge of a person with lung cancer (50%). Most reported hearing of the study from the newspaper (58%) despite no print ad yet being distributed. With survey input, a newsprint campaign was executed. The number of media events varied by site (median: 13, range: 3-28). Among all recruits, 56.4% reported referral by newspaper followed by family/friend (14%). Telephone contacts and recruited subjects per event varied significantly by site, while unpaid media events appeared superior to paid events. Print media characteristics associated with increased telephone contacts and recruitment included use of a rational appeal (vs a mixed rational-emotional), less use of white space, and larger headline font.

CONCLUSION

A survey of trial candidates provides useful information regarding personal motivation, media use, and lifestyle. Unpaid media events appear superior in generating recruitment, while print media may be superior to radio and television in selecting eligible recruits. The utility of individual print media characteristics appears to differ from the commercial advertising literature. Further research on marketing in clinical trials is encouraged to improve recruitment ( ClinicalTrials.gov registration: NCT00751660, https://clinicaltrials.gov/ct2/show/NCT00751660 ).

A Rare Complication: Development of an Aspergilloma after Endobronchial Coil Placement in a COPD Patient

Endobronchial coils are a relatively novel endoscopic lung volume reduction modality that aims to increase functional capacity in chronic obstructive pulmonary disease (COPD) patients. Two major trials have studied the safety and efficacy of this therapy, but long-term safety has not been studied. Adverse events reported are mainly periprocedural pneumothoraces and early bacterial infectious complications. We report the case of a patient with severe emphysema (Global Initiative for Chronic Obstructive Lung Disease stage IV COPD) who developed endobronchial coil-associated aspergillomas 3 years after coil placement.

Simplified Criteria Using Pleural Fluid Cholesterol and Lactate Dehydrogenase to Distinguish between Exudative and Transudative Pleural Effusions

BACKGROUND

An important part of the investigation of pleural effusion is the identification of markers that help separate exudate from transudate.

OBJECTIVES

The purposes of this study were to compare the accuracy of published and new sets of criteria to distinguish between exudative and transudative pleural effusions, and to determine whether serum biochemical analysis is necessary.

METHODS

An externally validated cohort study was performed. Pleural effusions were determined to be transudative or exudative on the basis of an assessment of the medical record by two clinicians blinded to biochemical results. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and area under the receiver operating characteristic curve were determined for each proposed combination of criteria.

RESULTS

Pleural fluid analysis was available for 311 thoracenteses in the main cohort and for 112 thoracenteses in the validation cohort. The best sensitivity (97% [95% CI 94-99]) and negative likelihood ratio (0.04 [95% CI 0.02-0.08]) for identifying exudative effusions were observed with criteria combining pleural fluid lactate dehydrogenase greater than 0.6 the upper limit of normal serum lactate dehydrogenase and pleural fluid cholesterol greater than 1.04 mmol/L (40 mg/dL). The overall diagnostic accuracy was similar to Light's criteria. Findings were similar in the validation cohort.

CONCLUSIONS

Our proposed criteria using simultaneously pleural fluid lactate dehydrogenase and pleural fluid cholesterol can identify an exudate with a sensitivity and an overall diagnostic accuracy similar to Light's criteria. It avoids simultaneous blood sampling, thus reducing patient discomfort and potential costs.

Health-related quality of life and anxiety in the PAN-CAN lung cancer screening cohort

OBJECTIVES

The impact of lung cancer screening with low-dose chest CT (LDCT) on participants' anxiety levels and health-related quality of life (HRQoL) is an important consideration in the implementation of such programmes. We aimed to describe changes in anxiety and HRQoL in a high-risk Canadian cohort undergoing LDCT lung cancer screening.

METHODS

2537 subjects who had 2% or greater lung cancer risk over 6 years using a risk prediction tool were recruited from eight centres across Canada in the Pan-Canadian Early Detection of Lung Cancer Study (2008-2010). We compared HRQoL and anxiety levels before and after screening of 1237 participants with LDCT (excluding a subset of 1300 participants who also underwent autofluorescence bronchoscopy screening), as well as after investigations performed because of a positive screening examination. The 12-item short-form Physical and Mental Component Scales (SF-12), EQ-5D-3L scores and State Trait Anxiety Inventory-State anxiety were used at each assessment.

RESULTS

Overall, there were no clinically significant differences in HRQoL outcomes between baseline and each of the survey time points following initial screening. No mean change in anxiety in the overall cohort was noted following baseline LDCT, but more participants had clinically significant increase in anxiety versus decrease after baseline screening (increase >minimal clinically important difference (MCID) (n=180) vs decrease >MCID (n=50), p<0.001). This finding persisted but to a lesser degree at the 12 month time point (increase >MCID (n=146) vs decrease >MCID (n=87), p<0.001).

CONCLUSIONS

CT screening for lung cancer has no major overall impact on HRQoL among participants, although a minority of participants (number-needed-to-harm=7 after baseline screening and 18 at 1 year) demonstrated clinically significant increased anxiety levels.

TRIALREGISTRATION NUMBER

NCT00751660; Results.

Adherence to guidelines in requesting Oncotype DX in a publicly funded health care system

Background

Oncotype dx [odx (Genomic Health, Redwood City, CA, U.S.A.)] is an approved prognostic tool for women with node-negative, hormone receptor-positive, her2-negative breast cancer. Because of cost, optimal use of this test is crucial, especially in a publicly funded health care system. We evaluated adherence with our provincial guidelines for odx requests, the management of patients with an intermediate recurrence score (rs), and the cost impact of odx.

Methods

This retrospective study included 201 consecutive patients with an odx request from two university institutions in Quebec between May 2012 and December 2014. Concordance with provincial guidelines was estimated, with its 95% confidence interval (ci). For patients with an intermediate rs, factors influencing the final treatment decision were assessed. The cost impact of odx was derived from the proportion of patients for whom chemotherapy was not recommended.

Results

In 93.0% of patients (95% ci: 89.5% to 96.6%), odx was ordered according to guidelines. The concordance was similar in both institutions (92.7%; 95% ci: 88.1% to 97.3%; and 93.6%; 95% ci: 88.2% to 99.0%). In 112 (55.7%), 78 (38.8%), and 9 (4.5%) patients, the rs suggested low, intermediate, and high risk respectively. In the intermediate-risk group, most patients (n = 58, 74.4%) did not receive chemotherapy, mainly because of patient preference and the absence of a clear proven benefit. Savings of CA$100,000 for the study period (2.5 years) were estimated to be associated with odx use.

Conclusions

In our experience, the use of odx was concordant with published recommendations and had a positive cost impact.

Participant selection for lung cancer screening by risk modelling (the Pan-Canadian Early Detection of Lung Cancer [PanCan] study): a single-arm, prospective study

BACKGROUND

Results from retrospective studies indicate that selecting individuals for low-dose CT lung cancer screening on the basis of a highly predictive risk model is superior to using criteria similar to those used in the National Lung Screening Trial (NLST; age, pack-year, and smoking quit-time). We designed the Pan-Canadian Early Detection of Lung Cancer (PanCan) study to assess the efficacy of a risk prediction model to select candidates for lung cancer screening, with the aim of determining whether this approach could better detect patients with early, potentially curable, lung cancer.

METHODS

We did this single-arm, prospective study in eight centres across Canada. We recruited participants aged 50-75 years, who had smoked at some point in their life (ever-smokers), and who did not have a self-reported history of lung cancer. Participants had at least a 2% 6-year risk of lung cancer as estimated by the PanCan model, a precursor to the validated PLCOm2012 model. Risk variables in the model were age, smoking duration, pack-years, family history of lung cancer, education level, body-mass index, chest x-ray in the past 3 years, and history of chronic obstructive pulmonary disease. Individuals were screened with low-dose CT at baseline (T0), and at 1 (T1) and 4 (T4) years post-baseline. The primary outcome of the study was incidence of lung cancer. This study is registered with ClinicalTrials.gov, number NCT00751660.

FINDINGS

7059 queries came into the study coordinating centre and were screened for PanCan risk. 15 were duplicates, so 7044 participants were considered for enrolment. Between Sept 24, 2008, and Dec 17, 2010, we recruited and enrolled 2537 eligible ever-smokers. After a median follow-up of 5·5 years (IQR 3·2-6·1), 172 lung cancers were diagnosed in 164 individuals (cumulative incidence 0·065 [95% CI 0·055-0·075], incidence rate 138·1 per 10 000 person-years [117·8-160·9]). There were ten interval lung cancers (6% of lung cancers and 6% of individuals with cancer): one diagnosed between T0 and T1, and nine between T1 and T4. Cumulative incidence was significantly higher than that observed in NLST (4·0%; p<0·0001). Compared with 593 (57%) of 1040 lung cancers observed in NLST, 133 (77%) of 172 lung cancers in the PanCan Study were early stage (I or II; p<0·0001).

INTERPRETATION

The PanCan model was effective in identifying individuals who were subsequently diagnosed with early, potentially curable, lung cancer. The incidence of cancers detected and the proportion of early stage cancers in the screened population was higher than observed in previous studies. This approach should be considered for adoption in lung cancer screening programmes.

FUNDING

Terry Fox Research Institute and Canadian Partnership Against Cancer.

Influence of trainee involvement on procedural characteristics for linear endobronchial ultrasound

Background

Linear endobronchial ultrasound (EBUS) is a safe and effective method for the diagnostic sampling of mediastinal lymph nodes. However, there is a learning curve associated with the procedure and operator experience influences diagnostic yield. We sought to determine if trainee involvement during EBUS influences procedural characteristics, complication rate, and diagnostic yield.

Methods

We performed a retrospective analysis of 220 subjects who underwent an EBUS procedure at our center from December 2012 to June 2013. Procedures were performed by six different interventional pulmonologists with substantial experience with EBUS or by a trainee under their direct supervision. Procedural characteristics and complications were recorded. Diagnostic yield and specimen adequacy were compared between groups.

Results

EBUS was performed in 220 patients with a trainee involved (n = 116) or by staff physician alone (n = 104). Patient characteristics, and the number and size of lymph node stations sampled were similar. EBUS duration was longer (16.0 vs. 13.7 minutes; P = 0.002) and the total dose of lidocaine used was higher (322.3 vs. 304.2 mg; P = 0.045) when a trainee was involved. The rate of adequate specimens sampled was comparable between the groups (92.0 vs. 92.0%; P = 0.60). Diagnostic yield was lower when a trainee was involved in the EBUS procedure (52.6 vs. 68.3%; P = 0.02).

Conclusion

Trainee involvement significantly increased EBUS duration and the dose of local anesthesia used for the procedure. Diagnostic yield was lower when a trainee was involved. Factors accounting for this difference in yield, despite adequate samples being obtained, warrant further investigation.

Use of a marketing plan for recruitment to a lung cancer screening study

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Background: Recruitment to clinic trials is typically poor. Among barriers to recruitment may be the limited knowledge of trialists with respect to marketing techniques. Improvements in marketing could decrease recruitment time and shorten the time to access new interventions. We hypothesized that a marketing plan would improve recruitment to a lung cancer screening study. Methods: The Pan-Canadian Early Detection of Lung Cancer Trial recruited subjects from 8 centres to a screening study of low-dose CT scan and autofluorescence bronchoscopy. Recruitment processes were undertaken independently at each centre. One centre (M) used marketing expertise and a marketing plan, including surveying study candidates for motivators, resulting in specific newsprint advertisements. Screened trial candidates provided demographic and tobacco use data and indicated how they had heard about the study (bus, friend/family, MD, mail, newsprint, radio, TV, other). No site paid for radio or TV time. We used regression analyses to assess whether newsprint advertisements were more effective for recruitment at site M compared with all other sites. Results: From 2008 to 2010, 7059 candidates contacted all centres for eligibility screening, including 779 at centre M. Overall, 50.2% were female; median age was 59 yrs. Compared with other centres, candidates at centre M had less education (p < 0.001), a higher median 3-year lung cancer risk (2.3 vs 2.0%, p < 0.001), but were more likely to have learned of the study by newsprint (58.8 vs 53.3%, chi-squared p = 0.004), and were more likely to be recruited (44.0 vs 34.9%, p < 0.001). It was more likely that newsprint was the driver for screening contact among candidates with higher education level (OR 1.05/level), higher age (OR 1.03 / yr) and contact at site M (OR 1.31) (all < 0.001). Recruitment after eligibility screening was higher when newsprint was the driver for contact on univariable but not multivariable analysis. Conclusions: The effectiveness of newsprint advertising in motivating study contact may be improved by the formal use of marketing expertise. Newsprint advertising may improve the likelihood of recruitment after study screening, possibly through improved initial self-screening by the candidate. Clinical trial information: NCT00751660.

The Cost-Effectiveness of High-Risk Lung Cancer Screening and Drivers of Program Efficiency

INTRODUCTION

Lung cancer risk prediction models have the potential to make programs more affordable; however, the economic evidence is limited.

METHODS

Participants in the National Lung Cancer Screening Trial (NLST) were retrospectively identified with the risk prediction tool developed from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. The high-risk subgroup was assessed for lung cancer incidence and demographic characteristics compared with those in the low-risk subgroup and the Pan-Canadian Early Detection of Lung Cancer Study (PanCan), which is an observational study that was high-risk-selected in Canada. A comparison of high-risk screening versus standard care was made with a decision-analytic model using data from the NLST with Canadian cost data from screening and treatment in the PanCan study. Probabilistic and deterministic sensitivity analyses were undertaken to assess uncertainty and identify drivers of program efficiency.

RESULTS

Use of the risk prediction tool developed from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial with a threshold set at 2% over 6 years would have reduced the number of individuals who needed to be screened in the NLST by 81%. High-risk screening participants in the NLST had more adverse demographic characteristics than their counterparts in the PanCan study. High-risk screening would cost $20,724 (in 2015 Canadian dollars) per quality-adjusted life-year gained and would be considered cost-effective at a willingness-to-pay threshold of $100,000 in Canadian dollars per quality-adjusted life-year gained with a probability of 0.62. Cost-effectiveness was driven primarily by non-lung cancer outcomes. Higher noncurative drug costs or current costs for immunotherapy and targeted therapies in the United States would render lung cancer screening a cost-saving intervention.

CONCLUSIONS

Non-lung cancer outcomes drive screening efficiency in diverse, tobacco-exposed populations. Use of risk selection can reduce the budget impact, and screening may even offer cost savings if noncurative treatment costs continue to rise.

Abstract P2-05-30: OncotypeDX® for breast cancer: A multigene assay that makes a difference?

Objective: OncotypeDX® (ODX) is a multigene diagnostic assay that can estimate the 10 year-risk of distant recurrence in women with hormone receptor positive (HR+) and node negative (N–) early breast cancer. The testreports a Recurrence Score® (RS) and three risk group categories have been described: low-risk (&lt;18), intermediate-risk (18-30) and high-risk (≥31). It helps the oncologist in the adjuvant chemotherapy decision process and globally leads to a reduction in the recommendation for chemotherapy use. This test is expensive and represents an economic burden in a publicly funded province. Nonetheless, its use has been approved over other gene expression profiling like Mammaprint® based on the evidence of its prognostic and predictive ability. We evaluated the adequacy of the requests for the ODX in an academic setting after the introduction in May 2012 of a reference framework for its use in Québec, Canada and the impact on chemotherapy recommendation. The costs generated by the test were also determined. Methods: We included all patients with an ODX request from two University Centers, CICM and CHUS, and estimated the concordance with the current provincial guideline for which an ODX may be ordered (invasive breast cancer HR+/Her2–/N- that is T1b with unfavorable characteristics or T1c or T2). For the intermediate-risk group, the factors influencing the final decision to use systemic chemotherapy were analysed. The projected cost-effectiveness of the ODX was derived from the proportion of patients (pts) for which the chemotherapy was not recommended. Results: Between May 2012 and December 2014, a total of 201 pts, 123 pts from CICM and 78 from CHUS, had an ODX done. In 93,0% (95%CI, 89,5-96,6) of pts, ODX was ordered correctly with respect to the guideline. There was no statistical differences between both sites (CICM: 92,7% [95%CI, 97,3-88,1]; CHUS 93,6% [95%CI, 88,2-99,0]). A total of 9 pts had high-risk RS (4,5%), 78 pts had intermediate-risk RS (38,8%) and 112 pts had low-risk RS (55,7%). Chemotherapy was recommended for 31 pts (18,2%) instead of an estimated 58,0% prior to the use of ODX according to previous reports published. In the intermediate-risk group, the majority of pts (74,4%) did not receive chemotherapy. The patient's preference and the absence of a proven benefit were the main reasons for withholding chemotherapy in this group. The additional cost associated with the use of the ODX was compensated with the reduction of the adjuvant systemic chemotherapy prescribed and its derived expenses (chemotherapy cost, nursing time and hospitalisations) and savings of 100 K were observed. Conclusions: In early breast cancer HR+ and N-, the use of ODX in two University Hospitals is concordant with published recommendations. ODX use is cost effective. This benefice does not take into account the psychological burden that comes with the decision to use adjuvant chemotherapy; neither does it evaluate potential long term complications. The widespread use of ODX must be looked at critically in face of other emerging gene signature tests like Endopredict® and PAM50®. As for the predictive ability of the ODX for adjuvant chemotherapy, one can question the strength of the actual evidence and argue if it confers this test an advantage over other multigene assays.

Citation Format: Martel S, Prady C, Simon R, Matte C. OncotypeDX® for breast cancer: A multigene assay that makes a difference? [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-30.

Evaluation of Pulmonary Nodules Using the Spyglass Direct Visualization System Combined With Radial Endobronchial Ultrasound: A Clinical Feasibility Study

Background:

Sampling of peripheral pulmonary nodules with radial endobronchial ultrasound (p-EBUS) increases diagnostic yield of bronchoscopy. However, diagnostic yield is influenced by numerous factors.

Objective:

We evaluated the use of SpyGlass, a one millimeter diameter optic fiber, to obtain images of the distal mucosa and of pulmonary lesions detected with p-EBUS to determine if visual aspect of the distal mucosa was predictive of diagnosis.

Methods:

We prospectively recruited subjects investigated for peripheral nodules. Bronchoscopy was performed and p-EBUS was used to locate the lesion through a guide sheath. The Spyglass fiber was introduced in the sheath to obtain images of the distal bronchial mucosa. Tissue sampling was subsequently done.

Results:

Fifteen patients were enrolled in the study. A final diagnosis of malignancy was confirmed in 80%. All lesions could be located using p-EBUS (100%). Diagnostic sensitivity for p-EBUS was 58.3%. Distal mucosa could be imaged with SpyGlass in 14/15 patients (93.3%). Mucosal appearance was described as abnormal in 7 out of the 15 subjects. Mean SpyGlass procedure time was 6.5 minutes. No direct complication was reported.

Conclusion:

Spyglass can be used in combination with p-EBUS to obtain images of the distal bronchial mucosa and peripheral pulmonary nodules. More patients will be needed to confirm whether mucosal appearance can be predictive of malignancy.

Low Prevalence of High-Grade Lesions Detected With Autofluorescence Bronchoscopy in the Setting of Lung Cancer Screening in the Pan-Canadian Lung Cancer Screening Study

BACKGROUND

Lung cancer screening with low-dose CT (LDCT) scan has been demonstrated to reduce lung cancer mortality. Preliminary reports suggested that up to 20% of lung cancers may be CT scan occult but detectable by autofluorescence bronchoscopy (AFB). We evaluated the prevalence of CT scan occult, invasive, and high-grade preinvasive lesions in high-risk participants undergoing screening for lung cancer.

METHODS

The first 1,300 participants from seven centers in the Pan-Canadian Early Detection of Lung Cancer Study who had ≥ 2% lung cancer risk over 5 years were invited to have an AFB in addition to a LDCT scan. We determined the prevalence of CT scan and AFB abnormalities and analyzed the association between selected predictor variables and preinvasive lesions plus invasive cancer.

RESULTS

A total of 776 endobronchial biopsies were performed in 333 of 1,300 (25.6%) participants. Dysplastic or higher-grade lesions were detected in 5.3% of the participants (n = 68; mild dysplasia: n = 36, moderate dysplasia: n = 25, severe dysplasia: n = 3, carcinoma in situ [CIS]: n = 1, and carcinoma: n = 4). Only one typical carcinoid tumor and one CIS lesion were detected by AFB alone, for a rate of CT scan occult cancer of 0.15% (95% CI, 0.0%-0.6%). Fifty-six prevalence lung cancers were detected by LDCT scan (4.3%). The only independent risk factors for finding of dysplasia or CIS on AFB were smoking duration (OR, 1.05; 95% CI, 1.02-1.07) and FEV₁ percent predicted (OR, 0.99; 95% CI, 0.98-0.99).

CONCLUSIONS

The addition of AFB to LDCT scan in a high lung cancer risk cohort detected too few CT occult cancers (0.15%) to justify its incorporation into a lung cancer screening program.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00751660; URL: www.clinicaltrials.gov.

Rotenone Neurotoxicity Causes Dopamine Neuron Loss in Zebrafish

ABSTRACT:Objectives: We sought to determine whether rotenone, a commonly used pesticide, exhibits neurotoxicity in zebrafish by causing dopamine neuron loss through rotenone-induced oxidative damage. Methods: We exposed transgenic zebrafish embryos expressing green fluorescent protein under the control of the cis-regulatory elements of dopamine transporter (dat) to rotenone to determine the neurotoxic effects of rotenone on dopamine neuron abundance and pattern distribution, as well as the presence of apoptotic markers. The oxidative stress potential of rotenone on embryos was assessed using a live MitoSOX Red assay, and behavioural testing on adult zebrafish was assessed using video recordings of midline crossing events. Results: Zebrafish embryos treated with rotenone displayed a 50% reduction in dopamine neurons in the ventral diencephalon when exposed to 30µM rotenone (n=6, p<0.001), and rotenone-exposed zebrafish raised to adulthood demonstrate an anxiety-like behaviour (n=5, p<0.01). Furthermore embryos exposed to rotenone also demonstrated a logarithmic increase in markers of oxidative damage (n=3, p<0.001) and apoptotic activity in their diencephalic neurons. Conclusions: These results show that rotenone can induce dopamine neuron loss in zebrafish, providing a useful model for studying the environmental causes of Parkinson’s disease. RÉSUMÉ:Objectif: Nous cherchons à déterminer si la roténone, un élément commun dans les pesticides, démontre de la neurotoxicité dans les poissons-zèbres en causant une perte de dopamine dans leurs neurones à travers le dommage oxydatif induit par la roténone. Méthode: Nous avons exposé des embryons de poissons-zèbres transgéniques qui expriment la protéine fluorescente verte sous le contrôle d’éléments cis-régulateurs des transporteurs sélectifs de dopamine (dat) à la roténone pour déterminer les effets neurotoxiques de ce dernier sur les niveaux dopaminergiques dans leurs neurones. De plus, nous avons évalué la présence de marqueurs apoptotiques. Le stress oxydatif potentiel de la roténone sur les embryons a été analysé par le « live MitoSOX Red assay » et les tests comportementaux sur les poissons-zèbres adultes furent analysés en utilisant des enregistrements vidéo. Résultats: Les embryons de poissons-zèbres qui ont été traités avec la roténone ont démontré une réduction de dopamine de 50% dans les neurones localisés dans le diencéphale ventral, quand exposés à 30µM de roténone (n=6, p<0.001). Ils ont également illustré une augmentation logarithmique dans les marqueurs de dommage oxydatif (n=3, p<0.001) et une activité apoptotique dans les neurones du diencéphale. Les poissons-zèbres exposés à de la roténone qui ont atteint l’âge adulte ont démontré des comportements d’anxiété (n=5, p<0.01). Conclusion: Les résultats démontrent que la roténone peut induire une perte dopaminergique dans les neurones des poissons-zèbres. Ces résultats s’avèrent utiles pour étudier davantage les causes environnementales reliées à la maladie de Parkinson.

Diagnostic yield of non-guided flexible bronchoscopy for peripheral pulmonary neoplasia

Background

The role of conventional bronchoscopy for peripheral pulmonary neoplasia remains controversial. We aimed to assess the diagnostic yield and the added value of non-guided bronchial aspiration, bronchoalveolar lavage (BAL), and brushing for the diagnosis of pulmonary neoplasia not visible endoscopically.

Methods

We retrospectively assessed 207 consecutive patients with a final diagnosis of peripheral lung malignancy who underwent bronchoscopy with non-guided aspiration, brushing, and BAL as their initial evaluation. The influence of clinical and radiological factors on diagnostic yield was assessed using univariate logistic regression analyses.

Results

The overall sensitivity of non-guided bronchoscopy was 25.6%, whereas sensitivities for bronchial aspiration, BAL, and brushing were 14.2%, 11.6%, and 16.5%, respectively. Younger age, larger lesion, central/intermediate distance from the hilum, presence of a bronchus sign, and higher standardized uptake value (SUV) on positron emission tomography scan were predictors of a higher diagnostic yield. Conversely, forced expiratory volume in one second, fellow implication in the procedure, and tumor histology did not influence sensitivity. The overall sensitivity of bronshoscopy was >40% for tumors >4 cm, located in the central/intermediate thirds of the lung, showing a bronchus sign, with an SUV >12 or occurring in patients <50 years of age. Conversely, the sensitivity was <10% for tumors <2 cm, located peripherally or with an SUV <4.

Conclusion

Neoplasia characteristics may help targeting situations in which conventional bronchoscopy could be used as the initial diagnostic procedure when advanced techniques are unavailable. However, advanced diagnostic tools should probably be proposed as the initial modality for the diagnosis of peripheral malignant lesions when available.

Plasma pro-surfactant protein B and lung function decline in smokers

Plasma pro-surfactant protein B (pro-SFTPB) levels have recently been shown to predict the development of lung cancer in current and ex-smokers, but the ability of pro-SFTPB to predict measures of chronic obstructive pulmonary disease (COPD) severity is unknown. We evaluated the performance characteristics of pro-SFTPB as a biomarker of lung function decline in a population of current and ex-smokers. Plasma pro-SFTPB levels were measured in 2503 current and ex-smokers enrolled in the Pan-Canadian Early Detection of Lung Cancer Study. Linear regression was performed to determine the relationship of pro-SFTPB levels to changes in forced expiratory volume in 1 s (FEV1) over a 2-year period as well as to baseline FEV1 and the burden of emphysema observed in computed tomography (CT) scans. Plasma pro-SFTPB levels were inversely related to both FEV1 % predicted (p=0.024) and FEV1/forced vital capacity (FVC) (p<0.001), and were positively related to the burden of emphysema on CT scans (p<0.001). Higher plasma pro-SFTPB levels were also associated with a more rapid decline in FEV1 at 1 year (p=0.024) and over 2 years of follow-up (p=0.004). Higher plasma pro-SFTPB levels are associated with increased severity of airflow limitation and accelerated decline in lung function. Pro-SFTPB is a promising biomarker for COPD severity and progression.

Diagnostic utility of peripheral endobronchial ultrasound with electromagnetic navigation bronchoscopy in peripheral lung nodules

BACKGROUND AND OBJECTIVE

This study aimed to investigate the diagnostic utility of peripheral endobronchial ultrasound (pEBUS) followed by as-needed electromagnetic navigation bronchoscopy (ENB) for sampling peripheral lung nodules.

METHODS

The study was a single-arm, prospective cohort study of patients with peripheral lung nodules. Peripheral lung lesion localization was initially performed using a pEBUS probe with guide sheath. If localization failed with pEBUS alone, ENB was used to help identify the lesion. Transbronchial biopsy, bronchial brush, transbronchial needle aspiration and bronchial washings were performed.

RESULTS

Sixty patients were enrolled with average lesion size of 27 mm and mean pleural distance of 20 mm. Lesions were found with pEBUS alone in 75% of cases. The addition of ENB improved lesion localization to 93%. However, diagnostic yield for pEBUS alone and pEBUS with ENB were 43% and 50%, respectively. Factors predicting need for ENB use included smaller lesion size and absence of an air bronchus sign on computed tomography.

CONCLUSIONS

ENB improves localization of lung lesions after unsuccessful pEBUS but is often not sufficient to ensure confirmation of a specific diagnosis. Technical improvements in sampling methods could improve the diagnostic yield.

Probability of cancer in pulmonary nodules detected on first screening CT

BACKGROUND

Major issues in the implementation of screening for lung cancer by means of low-dose computed tomography (CT) are the definition of a positive result and the management of lung nodules detected on the scans. We conducted a population-based prospective study to determine factors predicting the probability that lung nodules detected on the first screening low-dose CT scans are malignant or will be found to be malignant on follow-up.

METHODS

We analyzed data from two cohorts of participants undergoing low-dose CT screening. The development data set included participants in the Pan-Canadian Early Detection of Lung Cancer Study (PanCan). The validation data set included participants involved in chemoprevention trials at the British Columbia Cancer Agency (BCCA), sponsored by the U.S. National Cancer Institute. The final outcomes of all nodules of any size that were detected on baseline low-dose CT scans were tracked. Parsimonious and fuller multivariable logistic-regression models were prepared to estimate the probability of lung cancer.

RESULTS

In the PanCan data set, 1871 persons had 7008 nodules, of which 102 were malignant, and in the BCCA data set, 1090 persons had 5021 nodules, of which 42 were malignant. Among persons with nodules, the rates of cancer in the two data sets were 5.5% and 3.7%, respectively. Predictors of cancer in the model included older age, female sex, family history of lung cancer, emphysema, larger nodule size, location of the nodule in the upper lobe, part-solid nodule type, lower nodule count, and spiculation. Our final parsimonious and full models showed excellent discrimination and calibration, with areas under the receiver-operating-characteristic curve of more than 0.90, even for nodules that were 10 mm or smaller in the validation set.

CONCLUSIONS

Predictive tools based on patient and nodule characteristics can be used to accurately estimate the probability that lung nodules detected on baseline screening low-dose CT scans are malignant. (Funded by the Terry Fox Research Institute and others; ClinicalTrials.gov number, NCT00751660.).

Accurate positioning of magnetic microparticles beyond the spatial resolution of clinical MRI scanners using susceptibility artifacts

Susceptibility-based negative contrast in magnetic resonance imaging (MRI) provides a mean to visualize magnetic microparticles. In the presence of a number of microparticles in the field of view (FOV), the shape of the artifact is affected by the dipole-dipole interaction between the particles. Due to the limited spatial resolution of the clinical MR scanners, the exact positioning of the particles in MR images is not possible. However, the shape of the artifact can shed light on how the particles are distributed within the FOV. In this work, a simulation model and in-vitro experiments were used to study the shape and the amount of the susceptibility artifact for various spacing and angulations between the microparticles. The results showed that for a pair of identical particles with a diameter of D, the signal loss starts to change when particles are separated ~15 × D and they become fully distinguishable when their distance reaches ~ 40 × D.