Background: Pulmonary nodules are among the most frequent and medically relevant incidental findings, but are easily overlooked – especially when discovered incidentally during hospitalization. While CT imaging has become an invaluable tool for expedited medical evaluation, its use has been associated with an increasing number of incidental findings, the handling of which creates both medical and logistical challenges. While each isolated pulmonary nodule carries a relatively low risk of malignancy, clear guidelines exist for the proper handling of such nodules in order to minimize further associated morbidity and mortality. Despite these guidelines, appropriate follow up is missing for over two-thirds of patients with incidental pulmonary nodules. Little data is currently available reporting frequency and rate of follow up imaging for incidental pulmonary nodules
Methods: This was a retrospective cohort study of hospitalized patients ≥35 years of age who underwent in-patient CT abdomen from 2012-2014. Those patients with CT Chest imaging done during that hospitalization or within 30 days prior to admission were excluded to ensure that pulmonary nodules were incidental and asymptomatic. Nodule size, characteristics, and stability compared to available prior imaging were noted in addition to patient age, gender, smoking status and prior history of malignancy. A review of 7173 in-patient CT Abdominal studies done from 2012-2014 in patients aged 35 years or greater was performed to determine the prevalence of incidental pulmonary nodules mentioned in radiology reports and the the frequency of follow up with CT chest imaging as recommended by Fleischner guidelines.
Results: Incidental pulmonary nodules were noted in 217 patients (3%), of whom, 95.4% were Caucasian, 58.1% were men, 66.8 were current or former smokers. The majority of patients had maximum nodule size of 4.1-6.0 mm (36.5%). Of 217 patients, 194 (89.4%) were alive, not on hospice and met criteria for follow up screening. Based on Fleischner guidelines, taking smoking status, nodule size, and reported size stability into account, 19 patients (9.8%) required follow up imaging in 3 months, 33 patients (17%) in 3-6 months, 43 patients (25.3%) in 6-12 months, 93 patients (47.9%) in 12 monthsWe analyzed patients receiving appropriate follow up imaging before or after 3 months on either side of the recommended timeframe. Only 3 patients (15.8%) underwent follow up imaging in 3 months, 14 patients (42.4%) in 3-6 months, 9 patients (22.4%) in 6-12 months and 7 patients (7.5%) in 12 months. Of the total 194 nodules needing surveillance, only 39 patients (20.1%) had discharge summary documentation mentioning pulmonary nodules. Additional analyses in ongoing to determine factors that are associated with appropriate follow up of incidental nodules detected on CT abdominal imaging
Conclusions: Pulmonary incidental nodules mentioned in radiology reports from in-patient CT abdominal imaging are likely under-documented in the discharge summary, potentially contributing to poor follow-up rates and missed opportunities for early diagnosis. Further system-based interventions may be required to improve follow up imaging
