Fleischner Society Guideline Recommendations for Incidentally Detected Pulmonary Nodules and the Probability of Lung Cancer.

PURPOSE: The Fleischner Society aims to limit further evaluations of incidentally detected pulmonary nodules when the probability of lung cancer is <1% and to pursue further evaluations when the probability of lung cancer is ≥1%. To evaluate the internal consistency of guideline goals and recommendations, the authors evaluated stratum-specific recommendations and 2-year probabilities of lung cancer. METHODS: A retrospective cohort study (2005-2015) was conducted of individuals enrolled in one of two integrated health systems with solid nodules incidentally detected on CT. The 2017 Fleischner Society guidelines were used to define strata on the basis of smoking status and nodule size and number. Lung cancer diagnoses within 2 years of nodule detection were ascertained using cancer registry data. Confidence interval (CI) inspection was used to determine if stratum-specific probabilities of lung cancer were different than 1%. RESULTS: Among 5,444 individuals with incidentally detected lung nodules (median age, 66 years; 54% women; 57% smoked; median nodule size, 5.5 mm; 55% with multiple nodules), 214 (3.9%; 95% CI, 3.4%-4.5%) were diagnosed with lung cancer within 2 years. For 7 of 12 strata (58%), 2,765 patients (51%), and 194 lung cancer cases (91%), there was alignment between Fleischner Society goals and recommendations. Alignment was indeterminate for 5 strata (42%), 2,679 patients (49%), and 20 lung cancer cases (9%) because CIs for the probability of lung cancer spanned 1%. CONCLUSIONS: Fleischner Society guideline goals and recommendations align at least half the time. It is uncertain whether alignment of guideline goals and recommendations occurs more often.

Early detection of lung cancer using ultra-low-dose computed tomography in coronary CT angiography scans among patients with suspected coronary heart disease.

OBJECTIVES: To assess whether an additional chest ultra-low-dose CT scan to the coronary CT angiography protocol can be used for lung cancer screening among patients with suspected coronary artery disease. METHODS: 175 patients underwent coronary CT angiography for assessment of coronary artery disease, additionally undergoing ultra-low-dose CT screening to early diagnosis of lung cancer in the same scanner (80kVp and 15mAs). Patients presenting pulmonary nodules were followed-up for two years, repeating low-dose CTs in intervals of 3, 6, or 12 months based on nodule size and growth rate in accordance with National Comprehensive Cancer Network guidelines. RESULTS: Ultra-low-dose CT identified 71 patients with solitary pulmonary nodules (41%), with a mean diameter of 5.50±4.00mm. Twenty-eight were >6mm, and in 79% (n=22) of these cases they were false positive findings, further confirmed by follow-up (n=20), resection (n=1), or biopsy (n=1). Lung cancer was detected in six patients due to CT screening (diagnostic yield: 3%). Among these, four cases could not be detected in the cardiac field of view. Most patients were in early stages of the disease. Two patients diagnosed at advanced stages died due to cancer complications. The addition of the ultra-low-dose CT scan represented a radiation dose increment of 1.22±0.53% (effective dose, 0.11±0.03mSv). CONCLUSIONS: Lung cancer might be detected using additional ultra-low-dose protocols in coronary CT angiography scans among patients with suspected coronary artery disease.

Recent Trends in the Identification of Incidental Pulmonary Nodules.

RATIONALE: Pulmonary nodules are common incidental findings, but information about their incidence in the era of computed tomography (CT) is lacking. OBJECTIVES: To examine recent trends in pulmonary nodule identification. METHODS: We used electronic health records and natural language processing to identify members of an integrated health system who had nodules measuring 4 to 30 mm. We calculated rates of chest CT imaging, nodule identification, and receipt of a new lung cancer diagnosis within 2 years of nodule identification, and standardized rates by age and sex to estimate the frequency of nodule identification in the U.S. population in 2010. MEASUREMENTS AND MAIN RESULTS: Between 2006 and 2012, more than 200,000 adult members underwent 415,581 chest CT examinations. The annual frequency of chest CT imaging increased from 1.3 to 1.9% for all adult members, whereas the frequency of nodule identification increased from 24 to 31% for all scans performed. The annual rate of chest CT increased from 15.4 to 20.7 per 1,000 person-years, and the rate of nodule identification increased from 3.9 to 6.6 per 1,000 person-years, whereas the rate of a new lung cancer diagnosis remained stable. By extrapolation, more than 4.8 million Americans underwent at least one chest CT scan and 1.57 million had a nodule identified, including 63,000 who received a new lung cancer diagnosis within 2 years. CONCLUSIONS: Incidental pulmonary nodules are an increasingly common consequence of routine medical care, with an incidence that is much greater than recognized previously. More frequent nodule identification has not been accompanied by increases in the diagnosis of cancerous nodules.