Bassem Elaini MD, Presenter: Nothing to Disclose

Suzanne L. Aquino MD, Abstract Co-Author: Nothing to Disclose

Peter Florin Hahn MD, Abstract Co-Author: Nothing to Disclose

Leena M. Hamberg PhD, Abstract Co-Author: Nothing to Disclose

Elkan F. Halpern PhD, Abstract Co-Author: Nothing to Disclose

James Hunter Thrall MD, Abstract Co-Author: Nothing to Disclose

To determine the necessity of short-term follow-up imaging for incidentally detected noncalcified pulmonary nodules (NPN) in patients 40 years of age or younger without a history of malignancy or chronic systemic disease.

Thoracic CT scans performed between January 1998 and January 2004 detecting or following pulmonary nodules in patients 40 years of age or under at the time of initial scan were reviewed. Multi-detector row CT scanning (LightSpeed, GE Medical Systems, Milwaukee, WI) was performed in helical mode using 140kVp, 140mAs, pitch of 1.5 and 15mm table travel per rotation. 5mm images were reconstructed at 5mm intervals from the thoracic inlet to the adrenal glands. Patients were excluded if they had a history of neoplasm, infection, immunodeficiency, lack of at least 12 month follow-up, or nodules >/= 10mm at intake. Number, location, appearance, and change in size over time were parameters evaluated in each patient. Exact 95% confidence intervals (CI) were used to estimate chances of nodule growth.

486 patients 40 years of age or younger at the time of initial evaluation had a CT scan which detected at least one pulmonary nodule. 56 patients met inclusion criteria (mean age 33 years, 31 female, 25 male, 22 confirmed smokers). 26 patients had a single NPN, 30 patients had multiple NPNs. All patients had at least 12-month total follow-up (range 12-61 months, mean total follow-up 23.1 months). No interval growth was detected for any pulmonary nodule in any patient. Three patients’ nodules cleared. The median number of CT scans obtained between the initial scan and the 12-month follow-up scan was one (range 0-3). For each scan at our institution, the effective dose is approximately 10mSv, equivalent to that obtained from natural background radiation in 3.3 years. The exact 95% CI for the chance that a nodule would grow within 12-months is 0-0.06.

In young, healthy patients with pulmonary nodules 9mm or smaller by CT, we found no change in appearance over at least 12 months. A decrease in number of early interval follow-up scans (i.e. at 3 and 6 months) would result in significant reduction in radiation exposure in young patients.

Elaini, B, Aquino, S, Hahn, P, Hamberg, L, Halpern, E, Thrall, J, Incidentally Detected Noncalcified Pulmonary Nodules in Patients 40 Years of Age or Younger at Computed Tomography: Do Current Follow-up Recommendations Lead to Unnecessary Radiation Exposure?.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4405317.html