Nitra Piyavisetpat MD, PRESENTER: Nothing to Disclose

Abstract: HTML Purpose: To determine whether short-term (< 6 month) follow-up imaging by thoracic CT is necessary to evaluate small (£ 4 mm) noncalcified nodules (NCN) in patients with no history of malignancy or acute lung disease. Methods and Materials: We reviewed serial thoracic helical CT scans between 1999-2000 obtained for the evaluation or follow-up imaging of small NCNs. CT scans were performed at 5-mm collimation. Patients were excluded if they had a history of neoplasm, infection, pulmonary fibrosis, immune deficiency, solitary nodule ³ 5 mm at intake, or no follow-up scan within one year. NCNs were evaluated for number, size, configuration, and change in size over time. Exact 95% Confidence Intervals were used to estimate chances of developing malignancy in 3, 6, 12 month intervals. Results: A total of 1,826 patients received a CT for NCNs. 414 patients met inclusion criteria (221 women, 193 men, mean age, 65.6 years). Eighty-five patients had single NCN, 329 had multiple NCNs. 173 patients had additional ³ 5 mm nodules. One hundred twenty-seven patients were lost to follow up. No £4 mm NCN grew on follow-up imaging within 12 months. Eight nodules cleared. The chance of detecting a malignancy in 3, 6 and 12 months (95% CI) was less than 0.89%, 1.01% and 1.28% respectively. Three patients developed lung cancer in other nodules ³ 5 mm (5-10 mm). These nodules grew on follow up intervals of 3-13 months. One patient had a 19 mm benign hamartoma that grew in 9 months. Conclusion: The likelihood of detecting a malignancy in £ 4 mm NCN in a 3 to 12 months period in patients with no previous history of malignancy or immune disorder is small. Short-term follow-up imaging for nodules £ 4 mm is not necessary, but is recommended for nodules ³ 5 mm.      

Piyavisetpat MD, N, Small Incidental Pulmonary Nodules: How Useful is Short-term Interval CT Follow-up?.  Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL. http://archive.rsna.org/2003/3106834.html